MAX6358MSUT中文资料

高频信号发生器_______________概述MAX038是一种只需极少外围电路就能实现高 频、高精度输出三角波、锯齿波、正弦波、方波 和脉冲波的精密高频函数发生器芯片。

内部提供 的2.5V 基准电压和一个外接电阻和电容可以控制 输出频率范围在0.1Hz 到20MHz 。

占空比可在较大 的范围内由一个±2.3V的线性信号控制变化，便 于进行脉冲宽度调制和产生锯齿波。

频率调整和 频率扫描可以用同样的方式实现。

占空比和频率 控制是独立的。

通过设置2个TTL 逻辑地址引脚合适的逻辑电 平，能设定正弦波，方波或三角波的输出。

所有 波形的输出都是峰-峰值为±2VP -P 的信号。

低阻 抗输出能力可以达到±20mA。

____________________________性能o 频率调节范围：0.1Hz 到20MHzo 三角波, 锯齿波, 正弦波, 方波和脉冲波 o 频率和占空比独立可调 o 频率扫描范围：350：1 o 可控占空比：15%到85% o 低阻抗输出缓冲器： 0.1Ω o 低失真正弦波： 0.75% o 低温度漂移： 200ppm/°C______________型号信息TTL 逻辑地址引脚SYNC 从内部振荡器输出占 空比固定为50%的信号，不受其它波占空比的影 响，从而同步系统中其它振荡器。

内部振荡器 允许被连接着相位检波器输入端（PDI ）的外部 TTL 时钟同步。

型号 MAX038CPP MAX038CWP MAX038C/D MAX038EPP MAX038EWP工作温度 0°C 到 +70°C 0°C 到 +70°C 0°C 到 +70°C -40°C 到 +85°C -40°C 到 +85°C引脚--封装 20 Plastic DIP 20 SO Dice* 20 Plastic DIP 20 SO.__________________应用精密函数信号发生器 压控振荡器 频率调制器*Contact factory for dice specifications.__________________引脚图脉宽调制器 锁相环 频率合成器FSK 发生器（正弦波和方波）________________________________________________________________ Maxim Integrated Products1For free samples & the latest literature: , or phone 1-800-998-8800. For small orders, phone 408-737-7600 ext. 3468MAX038高频信号发生器图1. 内部结构及基本工作电路_______________ 详细说明MAX038是一种高频函数信号发生器，它可以使 用最少的外部元件而产生低失真正弦波，三角波， 锯齿波，方波（脉冲波）。

MAX485中文资料2009-11-28 14:49MAX485中文资料，MAX485 PDF,DATASHEET,电路图，通讯程序内容介绍：MAX481、MAX483、MAX485、MAX487-MAX491以及MAX1487是用于RS-485与RS-422通信的低功耗收发器，每个器件中都具有一个驱动器和一个接收器。

MAX483、MAX487、MAX488以及MAX489具有限摆率驱动器，可以减小EMI，并降低由不恰当的终端匹配电缆引起的反射，实现最高250kbps 的无差错数据传输。

MAX481、MAX485、MAX490、MAX491、MAX1487的驱动器摆率不受限制，可以实现最高2.5Mbps的传输速率。

这些收发器在驱动器禁用的空载或满载状态下，吸取的电源电流在120(A 至500(A 之间。

另外，MAX481、MAX483与MAX487具有低电流关断模式，仅消耗0.1µA。

所有器件都工作在5V单电源下。

驱动器具有短路电流限制，并可以通过热关断电路将驱动器输出置为高阻状态，防止过度的功率损耗。

接收器输入具有失效保护特性，当输入开路时，可以确保逻辑高电平输出。

MAX481,MAX483,MAX485,MAX487,MAX1487引脚（管脚）图及工作电路MAX485通讯程序与MAX232通讯程序在本质上是一样的，只是MAX485通讯程序需要加上通讯方向控制。

下面是基于mega128 16AU的485通信中断接收的程序，调试通过,晶振为外部16M,MAX485的DE和RE短接连PC0口，程序如下：#define SEND_485 PORTC|=0x01#define READ_485 PORTC&=0xfevoid Usart1_init(void) //16Mhz频率，设置波特率9.6k，8位数据位，无校验，接收发送使能，1位停止位{UBRR1H=0;UBRR1L=103;UCSR1B=(1<<RXCIE1)|(1<<RXEN1)|(1<<TXEN1); //发送接收使能，使用中断方式，UCSR1C=(1<<UCSZ10)|(1<<UCSZ11); //0x06 8位数据，1位停止位，无校验}void Usart1_transmit(unsigned char c) //查询方式发送接收字符函数{SEND_485;DelayBus();DelayBus();DelayBus();while( !(UCSR1A&(1<<UDRE1)));//等待发送缓冲区为空UDR1=c;while(!(UCSR1A&(1<<TXC1)));// UDCR0=c;UCSR1A |= _BV(TXC1);//将发送结束标志位清零// SET_BIT(UCSR1A,);READ_485;direction++;}SIGNAL(SIG_UART1_RECV)//serial port 1 {if(UCSR1A&(1<<RXC1)){rec1buff=UDR1;rec1_flag=1;。

MAX038芯片中文资料及在波形发生器中的应用(1)简介：波形发生器的应用范围很广。

在分析检测设备、超声设备、医疗设备及通讯设备中广泛应用。

函数发生器作为信号激励源，其参数精度是设计时应考虑的重要因素 ...波形发生器的应用范围很广。

在分析检测设备、超声设备、医疗设备及通讯设备中广泛应用。

函数发生器作为信号激励源，其参数精度是设计时应考虑的重要因素。

常用的波形产生电路有RC震荡电路、LC震荡电路、文氏震荡电路以及由555芯片构成的震荡电路等，但这些震荡电路由于核心芯片、选频及限幅元件特性的限制，在幅频精度方面或多或少的存在着不稳定或实现电路复杂等情况。

如果需要实现波形变换、幅频大小调整以及提高幅频的稳定度，设计的外围电路将会变得更为复杂。

由MAX038设计组成的波形产生电路能够输出幅频精度很高且易于调整的波形信号，在电路参数要求苛刻的工作场合能够得到较好的应用。

1 芯片功能介绍1．1 MAX038芯片的性能特点MAX038CPP芯片采用20引脚DIP封装，引脚图如图1所示。

各引脚功能简述如下：REF：芯片内部2．5 V参考电压输出；GND：模拟地；A1，A0：输出波形选择，TTL／CMOS兼容；COSC：内部震荡器外接电容；FADJ，DADJ：输出频率、占空比调节；IIN：震荡频率控制器电流输入；PDI，PDO：内部鉴相器输入、输出；SYNC：同步信号输出，允许内部震荡器与外电路同步；DGND，DV+：内部数字电路电源；V+，V-：MAX038电源(+5 V，-5 V)；OUT：波形输出端。

MAX038芯片附加少许外围电路就能够产生三角波、锯齿波、正弦波、方波、矩形脉冲波形。

该芯片具有如下的功能特点：(1)输出频率范围：0．1～20 MHz，最高可达40 MHz：(2)输出波形占空比(15％～85％)独立可调，占空比可由DADJ端调整，如果DADJ 端接地，则输出占空比为50％；(3)具有低输出阻抗的输出缓冲器，输出阻抗的典型值为0．1 Ω；(4)备有TTL兼容的独立同步信号SYNC(方波输出，固定占空比为50％)，方便组建频率合成器系统；(5)低温度漂移。

For pricing, delivery, and ordering information,please contact Maxim/Dallas Direct!at 1-888-629-4642, or visit Maxim’s website at .General DescriptionThe MAX481, MAX483, MAX485, MAX487–MAX491, and MAX1487 are low-power transceivers for RS-485 and RS-422 communication. Each part contains one driver and one receiver. The MAX483, MAX487, MAX488, and MAX489feature reduced slew-rate drivers that minimize EMI and reduce reflections caused by improperly terminated cables,thus allowing error-free data transmission up to 250kbps.The driver slew rates of the MAX481, MAX485, MAX490,MAX491, and MAX1487 are not limited, allowing them to transmit up to 2.5Mbps.These transceivers draw between 120µA and 500µA of supply current when unloaded or fully loaded with disabled drivers. Additionally, the MAX481, MAX483, and MAX487have a low-current shutdown mode in which they consume only 0.1µA. All parts operate from a single 5V supply.Drivers are short-circuit current limited and are protected against excessive power dissipation by thermal shutdown circuitry that places the driver outputs into a high-imped-ance state. The receiver input has a fail-safe feature that guarantees a logic-high output if the input is open circuit.The MAX487 and MAX1487 feature quarter-unit-load receiver input impedance, allowing up to 128 MAX487/MAX1487 transceivers on the bus. Full-duplex communi-cations are obtained using the MAX488–MAX491, while the MAX481, MAX483, MAX485, MAX487, and MAX1487are designed for half-duplex applications.________________________ApplicationsLow-Power RS-485 Transceivers Low-Power RS-422 Transceivers Level TranslatorsTransceivers for EMI-Sensitive Applications Industrial-Control Local Area Networks__Next Generation Device Features♦For Fault-Tolerant ApplicationsMAX3430: ±80V Fault-Protected, Fail-Safe, 1/4Unit Load, +3.3V, RS-485 TransceiverMAX3440E–MAX3444E: ±15kV ESD-Protected,±60V Fault-Protected, 10Mbps, Fail-Safe, RS-485/J1708 Transceivers♦For Space-Constrained ApplicationsMAX3460–MAX3464: +5V, Fail-Safe, 20Mbps,Profibus RS-485/RS-422 TransceiversMAX3362: +3.3V, High-Speed, RS-485/RS-422Transceiver in a SOT23 PackageMAX3280E–MAX3284E: ±15kV ESD-Protected,52Mbps, +3V to +5.5V, SOT23, RS-485/RS-422,True Fail-Safe ReceiversMAX3293/MAX3294/MAX3295: 20Mbps, +3.3V,SOT23, RS-855/RS-422 Transmitters ♦For Multiple Transceiver ApplicationsMAX3030E–MAX3033E: ±15kV ESD-Protected,+3.3V, Quad RS-422 Transmitters ♦For Fail-Safe ApplicationsMAX3080–MAX3089: Fail-Safe, High-Speed (10Mbps), Slew-Rate-Limited RS-485/RS-422Transceivers♦For Low-Voltage ApplicationsMAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E: +3.3V Powered, ±15kV ESD-Protected, 12Mbps, Slew-Rate-Limited,True RS-485/RS-422 TransceiversMAX481/MAX483/MAX485/MAX487–MAX491/MAX1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers______________________________________________________________Selection Table19-0122; Rev 8; 10/03Ordering Information appears at end of data sheet.M A X 481/M A X 483/M A X 485/M A X 487–M A X 491/M A X 1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers 2_______________________________________________________________________________________ABSOLUTE MAXIMUM RATINGSSupply Voltage (V CC ).............................................................12V Control Input Voltage (RE , DE)...................-0.5V to (V CC + 0.5V)Driver Input Voltage (DI).............................-0.5V to (V CC + 0.5V)Driver Output Voltage (A, B)...................................-8V to +12.5V Receiver Input Voltage (A, B).................................-8V to +12.5V Receiver Output Voltage (RO).....................-0.5V to (V CC +0.5V)Continuous Power Dissipation (T A = +70°C)8-Pin Plastic DIP (derate 9.09mW/°C above +70°C)....727mW 14-Pin Plastic DIP (derate 10.00mW/°C above +70°C)..800mW 8-Pin SO (derate 5.88mW/°C above +70°C).................471mW14-Pin SO (derate 8.33mW/°C above +70°C)...............667mW 8-Pin µMAX (derate 4.1mW/°C above +70°C)..............830mW 8-Pin CERDIP (derate 8.00mW/°C above +70°C).........640mW 14-Pin CERDIP (derate 9.09mW/°C above +70°C).......727mW Operating Temperature RangesMAX4_ _C_ _/MAX1487C_ A...............................0°C to +70°C MAX4__E_ _/MAX1487E_ A.............................-40°C to +85°C MAX4__MJ_/MAX1487MJA...........................-55°C to +125°C Storage Temperature Range.............................-65°C to +160°C Lead Temperature (soldering, 10sec).............................+300°CDC ELECTRICAL CHARACTERISTICS(V CC = 5V ±5%, T A = T MIN to T MAX , unless otherwise noted.) (Notes 1, 2)Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.V V IN = -7VV IN = 12V V IN = -7V V IN = 12V Input Current (A, B)I IN2V TH k Ω48-7V ≤V CM ≤12V, MAX487/MAX1487R INReceiver Input Resistance -7V ≤V CM ≤12V, all devices except MAX487/MAX1487R = 27Ω(RS-485), Figure 40.4V ≤V O ≤2.4VR = 50Ω(RS-422)I O = 4mA, V ID = -200mV I O = -4mA, V ID = 200mV V CM = 0V-7V ≤V CM ≤12V DE, DI, RE DE, DI, RE MAX487/MAX1487,DE = 0V, V CC = 0V or 5.25VDE, DI, RE R = 27Ωor 50Ω, Figure 4R = 27Ωor 50Ω, Figure 4R = 27Ωor 50Ω, Figure 4DE = 0V;V CC = 0V or 5.25V,all devices except MAX487/MAX1487CONDITIONSk Ω12µA ±1I OZRThree-State (high impedance)Output Current at ReceiverV 0.4V OL Receiver Output Low Voltage 3.5V OH Receiver Output High Voltage mV 70∆V TH Receiver Input Hysteresis V -0.20.2Receiver Differential Threshold Voltage-0.2mA 0.25mA-0.81.01.55V OD2Differential Driver Output (with load)V 2V 5V OD1Differential Driver Output (no load)µA±2I IN1Input CurrentV 0.8V IL Input Low Voltage V 2.0V IH Input High Voltage V 0.2∆V OD Change in Magnitude of Driver Common-Mode Output Voltage for Complementary Output States V 0.2∆V OD Change in Magnitude of Driver Differential Output Voltage for Complementary Output States V 3V OC Driver Common-Mode Output VoltageUNITS MINTYPMAX SYMBOL PARAMETERMAX481/MAX483/MAX485/MAX487–MAX491/MAX1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers_______________________________________________________________________________________3SWITCHING CHARACTERISTICS—MAX481/MAX485, MAX490/MAX491, MAX1487(V CC = 5V ±5%, T A = T MIN to T MAX , unless otherwise noted.) (Notes 1, 2)DC ELECTRICAL CHARACTERISTICS (continued)(V CC = 5V ±5%, T A = T MIN to T MAX , unless otherwise noted.) (Notes 1, 2)ns 103060t PHLDriver Rise or Fall Time Figures 6 and 8, R DIFF = 54Ω, C L1= C L2= 100pF ns MAX490M, MAX491M MAX490C/E, MAX491C/E2090150MAX481, MAX485, MAX1487MAX490M, MAX491MMAX490C/E, MAX491C/E MAX481, MAX485, MAX1487Figures 6 and 8, R DIFF = 54Ω,C L1= C L2= 100pF MAX481 (Note 5)Figures 5 and 11, C RL = 15pF, S2 closedFigures 5 and 11, C RL = 15pF, S1 closed Figures 5 and 11, C RL = 15pF, S2 closed Figures 5 and 11, C RL = 15pF, S1 closed Figures 6 and 10, R DIFF = 54Ω,C L1= C L2= 100pFFigures 6 and 8,R DIFF = 54Ω,C L1= C L2= 100pF Figures 6 and 10,R DIFF = 54Ω,C L1= C L2= 100pF CONDITIONS ns 510t SKEW ns50200600t SHDNTime to ShutdownMbps 2.5f MAX Maximum Data Rate ns 2050t HZ Receiver Disable Time from High ns 103060t PLH 2050t LZ Receiver Disable Time from Low ns 2050t ZH Driver Input to Output Receiver Enable to Output High ns 2050t ZL Receiver Enable to Output Low 2090200ns ns 134070t HZ t SKD Driver Disable Time from High |t PLH - t PHL |DifferentialReceiver Skewns 4070t LZ Driver Disable Time from Low ns 4070t ZL Driver Enable to Output Low 31540ns51525ns 31540t R , t F 2090200Driver Output Skew to Output t PLH , t PHL Receiver Input to Output4070t ZH Driver Enable to Output High UNITS MIN TYP MAX SYMBOL PARAMETERFigures 7 and 9, C L = 100pF, S2 closed Figures 7 and 9, C L = 100pF, S1 closed Figures 7 and 9, C L = 15pF, S1 closed Figures 7 and 9, C L = 15pF, S2 closedM A X 481/M A X 483/M A X 485/M A X 487–M A X 491/M A X 1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers 4_______________________________________________________________________________________SWITCHING CHARACTERISTICS—MAX483, MAX487/MAX488/MAX489(V CC = 5V ±5%, T A = T MIN to T MAX , unless otherwise noted.) (Notes 1, 2)SWITCHING CHARACTERISTICS—MAX481/MAX485, MAX490/MAX491, MAX1487 (continued)(V CC = 5V ±5%, T A = T MIN to T MAX , unless otherwise noted.) (Notes 1, 2)3001000Figures 7 and 9, C L = 100pF, S2 closed Figures 7 and 9, C L = 100pF, S1 closed Figures 5 and 11, C L = 15pF, S2 closed,A - B = 2VCONDITIONSns 40100t ZH(SHDN)Driver Enable from Shutdown toOutput High (MAX481)nsFigures 5 and 11, C L = 15pF, S1 closed,B - A = 2Vt ZL(SHDN)Receiver Enable from Shutdownto Output Low (MAX481)ns 40100t ZL(SHDN)Driver Enable from Shutdown toOutput Low (MAX481)ns 3001000t ZH(SHDN)Receiver Enable from Shutdownto Output High (MAX481)UNITS MINTYP MAX SYMBOLPARAMETERt PLH t SKEW Figures 6 and 8, R DIFF = 54Ω,C L1= C L2= 100pFt PHL Figures 6 and 8, R DIFF = 54Ω,C L1= C L2= 100pFDriver Input to Output Driver Output Skew to Output ns 100800ns ns 2000MAX483/MAX487, Figures 7 and 9,C L = 100pF, S2 closedt ZH(SHDN)Driver Enable from Shutdown to Output High2502000ns2500MAX483/MAX487, Figures 5 and 11,C L = 15pF, S1 closedt ZL(SHDN)Receiver Enable from Shutdown to Output Lowns 2500MAX483/MAX487, Figures 5 and 11,C L = 15pF, S2 closedt ZH(SHDN)Receiver Enable from Shutdown to Output Highns 2000MAX483/MAX487, Figures 7 and 9,C L = 100pF, S1 closedt ZL(SHDN)Driver Enable from Shutdown to Output Lowns 50200600MAX483/MAX487 (Note 5) t SHDN Time to Shutdownt PHL t PLH , t PHL < 50% of data period Figures 5 and 11, C RL = 15pF, S2 closed Figures 5 and 11, C RL = 15pF, S1 closed Figures 5 and 11, C RL = 15pF, S2 closed Figures 5 and 11, C RL = 15pF, S1 closed Figures 7 and 9, C L = 15pF, S2 closed Figures 6 and 10, R DIFF = 54Ω,C L1= C L2= 100pFFigures 7 and 9, C L = 15pF, S1 closed Figures 7 and 9, C L = 100pF, S1 closed Figures 7 and 9, C L = 100pF, S2 closed CONDITIONSkbps 250f MAX 2508002000Maximum Data Rate ns 2050t HZ Receiver Disable Time from High ns 25080020002050t LZ Receiver Disable Time from Low ns 2050t ZH Receiver Enable to Output High ns 2050t ZL Receiver Enable to Output Low ns ns 1003003000t HZ t SKD Driver Disable Time from High I t PLH - t PHL I DifferentialReceiver SkewFigures 6 and 10, R DIFF = 54Ω,C L1= C L2= 100pFns 3003000t LZ Driver Disable Time from Low ns 2502000t ZL Driver Enable to Output Low ns Figures 6 and 8, R DIFF = 54Ω,C L1= C L2= 100pFns 2502000t R , t F 2502000Driver Rise or Fall Time ns t PLH Receiver Input to Output2502000t ZH Driver Enable to Output High UNITS MIN TYP MAX SYMBOL PARAMETERMAX481/MAX483/MAX485/MAX487–MAX491/MAX1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers_______________________________________________________________________________________530002.5OUTPUT CURRENT vs.RECEIVER OUTPUT LOW VOLTAGE525M A X 481-01OUTPUT LOW VOLTAGE (V)O U T P U T C U R R E N T (m A )1.515100.51.02.0203540450.90.1-50-252575RECEIVER OUTPUT LOW VOLTAGE vs.TEMPERATURE0.30.7TEMPERATURE (°C)O U T P U TL O W V O L T A G E (V )500.50.80.20.60.40100125-20-41.5 2.0 3.0 5.0OUTPUT CURRENT vs.RECEIVER OUTPUT HIGH VOLTAGE-8-16M A X 481-02OUTPUT HIGH VOLTAGE (V)O U T P U T C U R R E N T (m A )2.5 4.0-12-18-6-14-10-203.54.5 4.83.2-50-252575RECEIVER OUTPUT HIGH VOLTAGE vs.TEMPERATURE3.64.4TEMPERATURE (°C)O U T P UT H I G H V O L T A G E (V )0504.04.63.44.23.83.01001259000 1.0 3.0 4.5DRIVER OUTPUT CURRENT vs.DIFFERENTIAL OUTPUT VOLTAGE1070M A X 481-05DIFFERENTIAL OUTPUT VOLTAGE (V)O U T P U T C U R R E N T (m A )2.0 4.05030806040200.5 1.5 2.53.5 2.31.5-50-2525125DRIVER DIFFERENTIAL OUTPUT VOLTAGEvs. TEMPERATURE1.72.1TEMPERATURE (°C)D I F FE R E N T I A L O U T P U T V O L T A G E (V )751.92.21.62.01.8100502.4__________________________________________Typical Operating Characteristics(V CC = 5V, T A = +25°C, unless otherwise noted.)NOTES FOR ELECTRICAL/SWITCHING CHARACTERISTICSNote 1:All currents into device pins are positive; all currents out of device pins are negative. All voltages are referenced to deviceground unless otherwise specified.Note 2:All typical specifications are given for V CC = 5V and T A = +25°C.Note 3:Supply current specification is valid for loaded transmitters when DE = 0V.Note 4:Applies to peak current. See Typical Operating Characteristics.Note 5:The MAX481/MAX483/MAX487 are put into shutdown by bringing RE high and DE low. If the inputs are in this state for lessthan 50ns, the parts are guaranteed not to enter shutdown. If the inputs are in this state for at least 600ns, the parts are guaranteed to have entered shutdown. See Low-Power Shutdown Mode section.M A X 481/M A X 483/M A X 485/M A X 487–M A X 491/M A X 1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers 6___________________________________________________________________________________________________________________Typical Operating Characteristics (continued)(V CC = 5V, T A = +25°C, unless otherwise noted.)120008OUTPUT CURRENT vs.DRIVER OUTPUT LOW VOLTAGE20100M A X 481-07OUTPUT LOW VOLTAGE (V)O U T P U T C U R R E N T (m A )6604024801012140-1200-7-5-15OUTPUT CURRENT vs.DRIVER OUTPUT HIGH VOLTAGE-20-80M A X 481-08OUTPUT HIGH VOLTAGE (V)O U T P U T C U R R E N T (m A )-31-603-6-4-2024-100-40100-40-60-2040100120MAX1487SUPPLY CURRENT vs. TEMPERATURE300TEMPERATURE (°C)S U P P L Y C U R R E N T (µA )20608050020060040000140100-50-2550100MAX481/MAX485/MAX490/MAX491SUPPLY CURRENT vs. TEMPERATURE300TEMPERATURE (°C)S U P P L Y C U R R E N T (µA )257550020060040000125100-50-2550100MAX483/MAX487–MAX489SUPPLY CURRENT vs. TEMPERATURE300TEMPERATURE (°C)S U P P L Y C U R R E N T (µA )257550020060040000125MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers_______________________________________________________________________________________7______________________________________________________________Pin DescriptionFigure 1. MAX481/MAX483/MAX485/MAX487/MAX1487 Pin Configuration and Typical Operating CircuitM A X 481/M A X 483/M A X 485/M A X 487–M A X 491/M A X 1487__________Applications InformationThe MAX481/MAX483/MAX485/MAX487–MAX491 and MAX1487 are low-power transceivers for RS-485 and RS-422 communications. The MAX481, MAX485, MAX490,MAX491, and MAX1487 can transmit and receive at data rates up to 2.5Mbps, while the MAX483, MAX487,MAX488, and MAX489 are specified for data rates up to 250kbps. The MAX488–MAX491 are full-duplex trans-ceivers while the MAX481, MAX483, MAX485, MAX487,and MAX1487 are half-duplex. In addition, Driver Enable (DE) and Receiver Enable (RE) pins are included on the MAX481, MAX483, MAX485, MAX487, MAX489,MAX491, and MAX1487. When disabled, the driver and receiver outputs are high impedance.MAX487/MAX1487:128 Transceivers on the BusThe 48k Ω, 1/4-unit-load receiver input impedance of the MAX487 and MAX1487 allows up to 128 transceivers on a bus, compared to the 1-unit load (12k Ωinput impedance) of standard RS-485 drivers (32 trans-ceivers maximum). Any combination of MAX487/MAX1487 and other RS-485 transceivers with a total of 32 unit loads or less can be put on the bus. The MAX481/MAX483/MAX485 and MAX488–MAX491 have standard 12k ΩReceiver Input impedance.Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers 8_______________________________________________________________________________________Figure 2. MAX488/MAX490 Pin Configuration and Typical Operating CircuitFigure 3. MAX489/MAX491 Pin Configuration and Typical Operating CircuitMAX483/MAX487/MAX488/MAX489:Reduced EMI and ReflectionsThe MAX483 and MAX487–MAX489 are slew-rate limit-ed, minimizing EMI and reducing reflections caused by improperly terminated cables. Figure 12 shows the dri-ver output waveform and its Fourier analysis of a 150kHz signal transmitted by a MAX481, MAX485,MAX490, MAX491, or MAX1487. High-frequency har-monics with large amplitudes are evident. Figure 13shows the same information displayed for a MAX483,MAX487, MAX488, or MAX489 transmitting under the same conditions. Figure 13’s high-frequency harmonics have much lower amplitudes, and the potential for EMI is significantly reduced.MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers_______________________________________________________________________________________9_________________________________________________________________Test CircuitsFigure 4. Driver DC Test Load Figure 5. Receiver Timing Test LoadFigure 6. Driver/Receiver Timing Test Circuit Figure 7. Driver Timing Test LoadM A X 481/M A X 483/M A X 485/M A X 487–M A X 491/M A X 1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers 10_______________________________________________________Switching Waveforms_________________Function Tables (MAX481/MAX483/MAX485/MAX487/MAX1487)Figure 8. Driver Propagation DelaysFigure 9. Driver Enable and Disable Times (except MAX488 and MAX490)Figure 10. Receiver Propagation DelaysFigure 11. Receiver Enable and Disable Times (except MAX488and MAX490)Table 1. TransmittingTable 2. ReceivingLow-Power Shutdown Mode (MAX481/MAX483/MAX487)A low-power shutdown mode is initiated by bringing both RE high and DE low. The devices will not shut down unless both the driver and receiver are disabled.In shutdown, the devices typically draw only 0.1µA of supply current.RE and DE may be driven simultaneously; the parts are guaranteed not to enter shutdown if RE is high and DE is low for less than 50ns. If the inputs are in this state for at least 600ns, the parts are guaranteed to enter shutdown.For the MAX481, MAX483, and MAX487, the t ZH and t ZL enable times assume the part was not in the low-power shutdown state (the MAX485/MAX488–MAX491and MAX1487 can not be shut down). The t ZH(SHDN)and t ZL(SHDN)enable times assume the parts were shut down (see Electrical Characteristics ).It takes the drivers and receivers longer to become enabled from the low-power shutdown state (t ZH(SHDN ), t ZL(SHDN)) than from the operating mode (t ZH , t ZL ). (The parts are in operating mode if the –R —E –,DE inputs equal a logical 0,1 or 1,1 or 0, 0.)Driver Output ProtectionExcessive output current and power dissipation caused by faults or by bus contention are prevented by two mechanisms. A foldback current limit on the output stage provides immediate protection against short cir-cuits over the whole common-mode voltage range (see Typical Operating Characteristics ). In addition, a ther-mal shutdown circuit forces the driver outputs into a high-impedance state if the die temperature rises excessively.Propagation DelayMany digital encoding schemes depend on the differ-ence between the driver and receiver propagation delay times. Typical propagation delays are shown in Figures 15–18 using Figure 14’s test circuit.The difference in receiver delay times, | t PLH - t PHL |, is typically under 13ns for the MAX481, MAX485,MAX490, MAX491, and MAX1487 and is typically less than 100ns for the MAX483 and MAX487–MAX489.The driver skew times are typically 5ns (10ns max) for the MAX481, MAX485, MAX490, MAX491, and MAX1487, and are typically 100ns (800ns max) for the MAX483 and MAX487–MAX489.MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers______________________________________________________________________________________1110dB/div0Hz5MHz500kHz/div10dB/div0Hz5MHz500kHz/divFigure 12. Driver Output Waveform and FFT Plot of MAX481/MAX485/MAX490/MAX491/MAX1487 Transmitting a 150kHz SignalFigure 13. Driver Output Waveform and FFT Plot of MAX483/MAX487–MAX489 Transmitting a 150kHz SignalM A X 481/M A X 483/M A X 485/M A X 487–M A X 491/M A X 1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers 12______________________________________________________________________________________V CC = 5V T A = +25°CV CC = 5V T A = +25°CV CC = 5V T A = +25°CV CC = 5V T A = +25°CFigure 14. Receiver Propagation Delay Test CircuitFigure 15. MAX481/MAX485/MAX490/MAX491/MAX1487Receiver t PHLFigure 16. MAX481/MAX485/MAX490/MAX491/MAX1487Receiver t PLHPHL Figure 18. MAX483, MAX487–MAX489 Receiver t PLHLine Length vs. Data RateThe RS-485/RS-422 standard covers line lengths up to 4000 feet. For line lengths greater than 4000 feet, see Figure 23.Figures 19 and 20 show the system differential voltage for the parts driving 4000 feet of 26AWG twisted-pair wire at 110kHz into 120Ωloads.Typical ApplicationsThe MAX481, MAX483, MAX485, MAX487–MAX491, and MAX1487 transceivers are designed for bidirectional data communications on multipoint bus transmission lines.Figures 21 and 22 show typical network applications circuits. These parts can also be used as line repeaters, with cable lengths longer than 4000 feet, as shown in Figure 23.To minimize reflections, the line should be terminated at both ends in its characteristic impedance, and stub lengths off the main line should be kept as short as possi-ble. The slew-rate-limited MAX483 and MAX487–MAX489are more tolerant of imperfect termination.MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers______________________________________________________________________________________13DIV Y -V ZRO5V 0V1V0V -1V5V 0V2µs/divFigure 19. MAX481/MAX485/MAX490/MAX491/MAX1487 System Differential Voltage at 110kHz Driving 4000ft of Cable Figure 20. MAX483, MAX487–MAX489 System Differential Voltage at 110kHz Driving 4000ft of CableFigure 21. MAX481/MAX483/MAX485/MAX487/MAX1487 Typical Half-Duplex RS-485 NetworkM A X 481/M A X 483/M A X 485/M A X 487–M A X 491/M A X 1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers 14______________________________________________________________________________________Figure 22. MAX488–MAX491 Full-Duplex RS-485 NetworkFigure 23. Line Repeater for MAX488–MAX491Isolated RS-485For isolated RS-485 applications, see the MAX253 and MAX1480 data sheets.MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers______________________________________________________________________________________15_______________Ordering Information_________________Chip TopographiesMAX481/MAX483/MAX485/MAX487/MAX1487N.C. RO 0.054"(1.372mm)0.080"(2.032mm)DE DIGND B N.C.V CCARE * Contact factory for dice specifications.__Ordering Information (continued)M A X 481/M A X 483/M A X 485/M A X 487–M A X 491/M A X 1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers 16______________________________________________________________________________________TRANSISTOR COUNT: 248SUBSTRATE CONNECTED TO GNDMAX488/MAX490B RO 0.054"(1.372mm)0.080"(2.032mm)N.C. DIGND Z A V CCYN.C._____________________________________________Chip Topographies (continued)MAX489/MAX491B RO 0.054"(1.372mm)0.080"(2.032mm)DE DIGND Z A V CCYREMAX481/MAX483/MAX485/MAX487–MAX491/MAX1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers______________________________________________________________________________________17Package Information(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to /packages .)S O I C N .E P SM A X 481/M A X 483/M A X 485/M A X 487–M A X 491/M A X 1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers 18______________________________________________________________________________________Package Information (continued)(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to /packages .)MAX481/MAX483/MAX485/MAX487–MAX491Low-Power, Slew-Rate-Limited RS-485/RS-422 TransceiversMaxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________19©2003 Maxim Integrated ProductsPrinted USAis a registered trademark of Maxim Integrated Products.M A X 481/M A X 483/M A X 485/M A X 487–M A X 491/M A X 1487P D I P N .E PSPackage Information (continued)(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to /packages .)。

DEVICE SPECIFICATIONSNI 6358X Series Data Acquisition: 1.25 MS/s/ch, 16 AI, 48 DIO, 4 AOThe following specifications are typical at 25 °C, unless otherwise noted. For more information about the NI 6358, refer to the X Series User Manual available from / manuals.Analog InputNumber of channels16 differentialADC resolution16 bitsDNL No missing codes guaranteedINL Refer to the AI Absolute Accuracy section. Sample rateSingle channel maximum 1.25 MS/sMinimum No minimumTiming resolution10 nsTiming accuracy50 ppm of sample rateInput coupling DCInput range±1 V, ±2 V, ±5 V, ±10 VMaximum working voltage for all analog inputsPositive input (AI+)±11 V for all ranges, Measurement Category I Negative input (AI-)±11 V for all ranges, Measurement Category I Caution Do not use for measurements within Categories II, III, and IV.CMRR (at 60 Hz)75 dBBandwidth 1 MHzTHD-80 dBFSInput impedanceDevice onAI+ to AI GND>100 GΩ in parallel with 100 pFAI- to AI GND>100 GΩ in parallel with 100 pF Device offAI+ to AI GND 2 kΩAI- to AI GND 2 kΩInput bias current±10 pACrosstalk (at 100 kHz)Adjacent channels-80 dBNon-adjacent channels-100 dBInput FIFO size8,182 samples shared among channels used Data transfers DMA (scatter-gather), programmed I/O Overvoltage protection for all analog input channelsDevice on±36 VDevice off±15 VInput current during overvoltage±20 mA max/AI pinconditionsAnalog T riggersNumber of triggers1Source AI <0..15>, APFI <0, 1>Functions Start Trigger, Reference Trigger, PauseTrigger, Sample Clock, Sample ClockTimebaseSource levelAI <0..15>±Full scaleAPFI <0, 1>±10 VResolution16 bitsModes Analog edge triggering, analog edge triggeringwith hysteresis, and analog window triggering 2| | NI 6358 Device SpecificationsBandwidth (-3 dB)AI <0..15> 3.4 MHzAPFI <0, 1> 3.9 MHz Accuracy±1% of range APFI <0, 1> characteristicsInput impedance10 kΩCoupling DCProtection, power on±30 VProtection, power off±15 VAI Absolute AccuracyNote For more information about absolute accuracy at full scale, refer to the AIAbsolute Accuracy Example section.Gain tempco8 ppm/°CReference tempco 5 ppm/°CResidual offset error15 ppm of rangeINL error46 ppm of rangeNote Accuracies listed are valid for up to two years from the device externalcalibration.AI Absolute Accuracy EquationAbsoluteAccuracy = Reading · (GainError) + Range · (OffsetError) + NoiseUncertainty GainError = ResidualGainError + GainTempco · (TempChangeFromLastInternalCal) + ReferenceTempco · (TempChangeFromLastExternalCal)NI 6358 Device Specifications| © National Instruments| 3OffsetError = ResidualOffsetError + OffsetTempco · (TempChangeFromLastInternalCal) + INLErrorNoiseUncertainty10,000 points.AI Absolute Accuracy ExampleAbsolute accuracy at full scale on the analog input channels is determined using the following assumptions:•TempChangeFromLastExternalCal = 10 °C •TempChangeFromLastInternalCal = 1 °C•number_of_readings = 10,000•CoverageFactor = 3 σFor example, on the 10 V range, the absolute accuracy at full scale is as follows: GainError = 114 ppm + 8 ppm · 1 + 5 ppm · 10 = 172 ppmOffsetError = 15 ppm + 35 ppm ·1 + 46 ppm = 96 ppmNoise UncertaintyAbsoluteAccuracy = 10 V · (GainError) + 10 V · (OffsetError) + NoiseUncertainty = 2688 µVAnalog OutputNumber of channels4DAC resolution16 bitsDNL±1 LSB, maxMonotonicity16 bit guaranteedAccuracy Refer to the AO Absolute Accuracy section. Maximum update rate (simultaneous)1 channel 3.3 MS/s2 channels 3.3 MS/s3 channels 3.3 MS/s4 channels 3.3 MS/sMinimum update rate No minimumTiming accuracy50 ppm of sample rateTiming resolution10 ns4| | NI 6358 Device SpecificationsOutput range±10 V, ±5 V, ±external reference onAPFI <0, 1>Output coupling DCOutput impedance0.4 ΩOutput current drive±5 mAOverdrive protection±25 VOverdrive current10 mAPower-on state±5 mVPower-on/off glitch 1.5 V peak for 200 msOutput FIFO size8,191 samples shared among channels used Data transfers DMA (scatter-gather), programmed I/OAO waveform modes Non-periodic waveform, periodic waveformregeneration mode from onboard FIFO,periodic waveform regeneration from hostbuffer including dynamic update2 µsSettling time, full-scale step,15 ppm (1 LSB)Slew rate20 V/µs6 nV · sGlitch energy at midscale transition,±10 V rangeExternal ReferenceAPFI <0, 1> characteristicsInput impedance10 kΩCoupling DCProtection, device on± 30 VProtection, device off± 15 VRange± 11 VSlew rate20 V/μsNI 6358 Device Specifications| © National Instruments| 5Figure 1. Analog Output External Reference Bandwidth–90–80–70–60–50–40–30–20–10010Frequency (Hz)N o r m a l i z e d A O A m p l i t u d e A t t e n u a t i o n (d B )AO Absolute AccuracyAbsolute accuracy at full-scale numbers is valid immediately following self calibration and assumes the device is operating within 10 °C of the last external calibration.Note Accuracies listed are valid for up to two years from the device externalcalibration.AO Absolute Accuracy EquationAbsoluteAccuracy = OutputValue ⋅ (GainError ) + Range ⋅ (OffsetError )GainError = ResidualGainError + GainTempco ⋅ (TempChangeFromLastInternalCal ) +ReferenceTempco ⋅ (TempChangeFromLastExternalCal )OffsetError = ResidualOffsetError + OffsetTempco ⋅ (TempChangeFromLastInternalCal )+ INLError6 | | NI 6358 Device SpecificationsDigital I/O/PFIStatic CharacteristicsNumber of channels48 total, 32 (P0.<0..31>,16 (PFI <0..7>/P1, PFI <8..15>/P2)Ground reference D GNDDirection control Each terminal individually programmable asinput or outputPull-down resistor50 kΩ typical, 20 kΩ minimumInput voltage protection±20 V on up to two pinsCaution Stresses beyond those listed under the Input voltage protectionspecification may cause permanent damage to the device.Waveform Characteristics (Port 0 Only)Terminals used Port 0 (P0.<0..31>)Port/sample size Up to 32 bitsWaveform generation (DO) FIFO2,047 samplesWaveform acquisition (DI) FIFO255 samplesDI Sample Clock frequency0 to 10 MHz, system and bus activitydependentDO Sample Clock frequencyRegenerate from FIFO0 to 10 MHzStreaming from memory0 to 10 MHz, system and bus activitydependentData transfers DMA (scatter-gather), programmed I/O Digital line filter settings160 ns, 10.24 μs, 5.12 ms, disablePFI/Port 1/Port 2 FunctionalityFunctionality Static digital input, static digital output, timinginput, timing outputTiming output sources Many AI, AO, counter, DI, DO timing signals Debounce filter settings90 ns, 5.12 µs, 2.56 ms, custom interval,disable; programmable high and lowtransitions; selectable per inputNI 6358 Device Specifications| © National Instruments| 7Recommended Operating Conditions Input high voltage (V IH)Minimum 2.2 VMaximum 5.25 VInput low voltage (V IL)Minimum0 VMaximum0.8 VOutput high current (I OH)P0.<0..7>-24 mA maximum PFI <0..15>/P1/P2-16 mA maximum Output low current (I OL)P0.<0..7>24 mA maximum PFI <0..15>/P1/P216 mA maximum Digital I/O CharacteristicsPositive-going threshold (VT+) 2.2 V maximum Negative-going threshold (VT-)0.8 V minimum Delta VT hysteresis (VT+ - VT-)0.2 V minimum I IL input low current (V IN = 0 V)-10 μA maximum I IH input high current (V IN = 5 V)250 μA maximum8| | NI 6358 Device SpecificationsFigure 2. P0.<0..31>: I OH versus V OHI O H (m A )–30–5–10–15–20–25–35–40–45V OH (V)0–50Figure 3. P0.<0..31>: I OL versus VOLI O L (m A )1535302520105V OL (V)400NI 6358 Device Specifications | © National Instruments | 9Figure 4. PFI <0..15>/P1/P2: I OH versus V OHI O H (m A )–30–5–10–15–20–25–35–40–45V OH (V)0–50Figure 5. PFI <0..15>/P1/P2: I OL versus V OLI O L (m A )5V OL (V)0General-Purpose CountersNumber of counter/timers 4Resolution32 bits10 | | NI 6358 Device SpecificationsCounter measurements Edge counting, pulse, pulse width,semi-period, period, two-edge separation Position measurements X1, X2, X4 quadrature encoding withChannel Z reloading; two-pulse encoding Output applications Pulse, pulse train with dynamic updates,frequency division, equivalent time sampling Internal base clocks100 MHz, 20 MHz, 100 kHzExternal base clock frequency0 MHz to 25 MHz; 0 MHz to 100 MHz onPXIe_DSTAR<A,B>Base clock accuracy50 ppmInputs Gate, Source, HW_Arm, Aux, A, B, Z,Up_Down, Sample ClockRouting options for inputs Any PFI, PXIe_DSTAR<A,B>, PXI_TRIG,PXI_STAR, analog trigger, many internaltriggersFIFO127 samples per counterData transfers Dedicated scatter-gather DMA controller foreach counter/timer, programmed I/OFrequency GeneratorNumber of channels1Base clocks20 MHz, 10 MHz, 100 kHzDivisors 1 to 16Base clock accuracy50 ppmOutput can be available on any PFI terminal.Phase-Locked Loop (PLL)Number of PLLs1NI 6358 Device Specifications| © National Instruments| 11Table 3. Reference Clock Locking Frequencies (Continued)Output of PLL100 MHz Timebase; other signals derived from100 MHz Timebase including 20 MHz and100 kHz TimebasesExternal Digital TriggersSource Any PFI, PXIe_DSTAR<A,B>, PXI_TRIG,PXI_STARPolarity Software-selectable for most signalsAnalog input function Start Trigger, Reference Trigger, PauseTrigger, Sample Clock, Convert Clock, SampleClock TimebaseAnalog output function Start Trigger, Pause Trigger, Sample Clock,Sample Clock TimebaseCounter/timer functions Gate, Source, HW_Arm, Aux, A, B, Z,Up_Down, Sample ClockDigital waveform generation (DO) function Start Trigger, Pause Trigger, Sample Clock, Sample Clock TimebaseDigital waveform acquisition (DI) function Start Trigger, Reference Trigger, Pause Trigger, Sample Clock, Sample Clock TimebaseDevice-to-Device T rigger BusInput source PXI_TRIG <0..7>, PXI_STAR,PXIe_DSTAR<A,B>Output destination PXI_TRIG <0..7>, PXIe_DSTARC 12| | NI 6358 Device SpecificationsOutput selections10 MHz Clock, frequency generator output,many internal signalsDebounce filter settings90 ns, 5.12 μs, 2.56 ms, custom interval,disable; programmable high and lowtransitions; selectable per inputBus InterfaceForm factor x1 PXI Express peripheral module,specification rev 1.0 compliantSlot compatibility x1 and x4 PXI Express or PXI Express hybridslotsDMA channels8, can be used for analog input, analog output,digital input, digital output, counter/timer 0,counter/timer 1, counter/timer 2,counter/timer 3All PXIe devices may be installed in PXI Express slots or PXI Express hybrid slots.Power RequirementsCaution The protection provided by the device can be impaired if the device isused in a manner not described in the X Series User Manual.PXIe+3.3 V7.8 W+12 V22.2 WCurrent LimitsCaution Exceeding the current limits may cause unpredictable device behavior.+5 V terminal (connector 0) 1 A max1+5 V terminal (connector 1) 1 A max11.8 A maxP0/PFI/P1/P2 and +5 V terminalscombined1Has a self-resetting fuse that opens when current exceeds this specification.NI 6358 Device Specifications| © National Instruments| 13Physical CharacteristicsPXIe printed circuit board dimensions Standard 3U PXIWeight241 g (8.5 oz)I/O connectors 2 68-pin VHDCI16-24 AWGUSB screw terminal/BNC screw terminalwiringCalibrationRecommended warm-up time15 minutesCalibration interval 2 yearsMaximum Working VoltageMaximum working voltage refers to the signal voltage plus the common-mode voltage. Channel to earth11 V, Measurement Category I Caution Do not use for measurements within Categories II, III, or IV.14| | NI 6358 Device SpecificationsShock and VibrationOperational shock30 g peak, half-sine, 11 ms pulse(Tested in accordance with IEC 60068-2-27.Test profile developed in accordance withMIL-PRF-28800F.)Random vibrationOperating 5 to 500 Hz, 0.3 g rmsNonoperating 5 to 500 Hz, 2.4 g rms(Tested in accordance with IEC 60068-2-64.Nonoperating test profile exceeds therequirements of MIL-PRF-28800F, Class 3.)EnvironmentalOperating temperature0 to 55 ºCStorage temperature-40 to 70 ºCOperating humidity10 to 90% RH, noncondensingStorage humidity 5 to 95% RH, noncondensingPollution Degree2Maximum altitude2,000 mIndoor use only.SafetyThis product is designed to meet the requirements of the following electrical equipment safety standards for measurement, control, and laboratory use:•IEC 61010-1, EN 61010-1•UL 61010-1, CSA 61010-1Note For UL and other safety certifications, refer to the product label or the OnlineProduct Certification section.Electromagnetic CompatibilityThis product meets the requirements of the following EMC standards for electrical equipment for measurement, control, and laboratory use:•EN 61326-1 (IEC 61326-1): Class A emissions; Basic immunity•EN 55011 (CISPR 11): Group 1, Class A emissionsNI 6358 Device Specifications| © National Instruments| 15•EN 55022 (CISPR 22): Class A emissions•EN 55024 (CISPR 24): Immunity•AS/NZS CISPR 11: Group 1, Class A emissions•AS/NZS CISPR 22: Class A emissions•FCC 47 CFR Part 15B: Class A emissions•ICES-001: Class A emissionsNote In the United States (per FCC 47 CFR), Class A equipment is intended foruse in commercial, light-industrial, and heavy-industrial locations. In Europe,Canada, Australia and New Zealand (per CISPR 11) Class A equipment is intendedfor use only in heavy-industrial locations.Note Group 1 equipment (per CISPR 11) is any industrial, scientific, or medicalequipment that does not intentionally generate radio frequency energy for thetreatment of material or inspection/analysis purposes.Note For EMC declarations and certifications, and additional information, refer tothe Online Product Certification section.CE ComplianceThis product meets the essential requirements of applicable European Directives, as follows:•2014/35/EU; Low-V oltage Directive (safety)•2014/30/EU; Electromagnetic Compatibility Directive (EMC)Online Product CertificationRefer to the product Declaration of Conformity (DoC) for additional regulatory compliance information. To obtain product certifications and the DoC for this product, visit / certification, search by model number or product line, and click the appropriate link in the Certification column.Environmental ManagementNI is committed to designing and manufacturing products in an environmentally responsible manner. NI recognizes that eliminating certain hazardous substances from our products is beneficial to the environment and to NI customers.For additional environmental information, refer to the Minimize Our Environmental Impact web page at /environment. This page contains the environmental regulations and directives with which NI complies, as well as other environmental information not included in this document.16| | NI 6358 Device SpecificationsWaste Electrical and Electronic Equipment (WEEE)EU Customers At the end of the product life cycle, all NI products must bedisposed of according to local laws and regulations. For more information about how to recycle NI products in your region, visit /environment/weee .电子信息产品污染控制管理办法（中国RoHS ）中国客户 National Instruments 符合中国电子信息产品中限制使用某些有害物质指令(RoHS )。

General DescriptionThe MAX6365–MAX6368 supervisory circuits simplify power-supply monitoring, battery-backup control func-tions, and memory write protection in microprocessor (µP) systems. The circuits significantly improve the size,accuracy, and reliability of modern systems with an ultra-small integrated solution.These devices perform four basic system functions:1) Provide a µP reset output during V CC supply power-up, power-down, and brownout conditions.2) Internally control V CC to backup-battery switching tomaintain data or low-power operation for CMOS RAM, CMOS µPs, real-time clocks, and other digital logic when the main supply fails.3) Provide memory write protection through internalchip-enable gating during supply or processor faults.4) Include one of the following options: a manual resetinput (MAX6365), a watchdog timer function (MAX6366), a battery-on output (MAX6367), or an auxiliary user-adjustable reset input (MAX6368).The MAX6365–MAX6368 operate from V CC supply volt-ages as low as 1.2V. The factory preset reset threshold voltages range from 2.32V to 4.63V (see Ordering Information ). In addition, each part is offered in three reset output versions: push-pull active low, open-drain active low, or open-drain active high (see Selector Guide ). The MAX6365–MAX6368 are available in minia-ture 8-pin SOT23 packages.ApplicationsCritical µP/µC Power Portable/Battery-Monitoring Powered Equipment Fax Machines Set-Top Boxes Industrial Control POS EquipmentComputers/ControllersFeatureso Low +1.2V Operating Supply Voltage (V CC or V BATT )o Precision Monitoring of +5.0V, +3.3V, +3.0V, and +2.5V Power-Supply Voltageso On-Board Gating of Chip-Enable Signals, 1.5ns Propagation Delayo Debounced Manual Reset Input (MAX6365)o Watchdog Timer, 1.6s Timeout (MAX6366)o Battery-On Output Indicator (MAX6367)o Auxiliary User-Adjustable RESET IN (MAX6368)o Low 10µA Quiescent Supply Current o Three Available Output StructuresPush-Pull RESET Open-Drain RESET Open-Drain RESETo RESET/RESET Valid Down to 1.2V Guaranteed (V CC or V BATT )o Power-Supply Transient Immunity o 150ms min Reset Timeout Period o Miniature 8-Pin SOT23 PackageMAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating________________________________________________________________Maxim Integrated Products1Pin Configurations19-1658; Rev 1; 6/01For pricing, delivery, and ordering information,please contact Maxim/Dallas Direct!at 1-888-629-4642, or visit Maxim’s website at .Ordering Information*These parts offer a choice of reset threshold voltages. From the Reset Threshold Ranges table, insert the desired threshold volt-age code in the blank to complete the part number. SOT parts come in tape-and-reel only and must be ordered in 2500-piece increments. See Device Marking Codes for a complete parts list,including SOT top marks and standard threshold versions. See Selector Guide for a listing of device features.Typical Operating Circuit appears at end of data sheet.M A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable GatingABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICS(V = +2.4V to +5.5V, V = +3.0V, CE IN = V , reset not asserted, T = -40°C to +85°C. Typical values are at T = +25°C,Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.Terminal Voltages (with respect to GND)V CC , BATT, OUT.......................................................-0.3V to +6V RESET (open drain), RESET (open drain)................-0.3V to +6V BATT ON, RESET (push-pull), RESET IN,WDI, CE IN, CE OUT...........................-0.3V to (V OUT + 0.3V)MR ..............................................................-0.3V to (V CC + 0.3V)Input CurrentV CC Peak ..............................................................................1A V CC Continuous.............................................................250mA BATT Peak.....................................................................250mA BATT Continuous.............................................................40mAGND...............................................................................75mA Output CurrentOUT...............................Short-Circuit Protected for up to 10s RESET, RESET , BATT ON, CE OUT...............................20mA Continuous Power Dissipation (T A = +70°C)8-Pin SOT23 (derate 8.75mW/°C above +70°C)........700mW Operating Temperature Range ...........................-40°C to +85°C Storage Temperature Range.............................-65°C to +150°C Junction Temperature .....................................................+150°C Lead Temperature (soldering, 10s).................................+300°CMAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating_______________________________________________________________________________________3ELECTRICAL CHARACTERISTICS (continued)(V CC = +2.4V to +5.5V, V BATT = +3.0V, CE IN = V CC , reset not asserted, T A = -40°C to +85°C. Typical values are at T A = +25°C,M A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating 4_______________________________________________________________________________________Typical Operating Characteristics(T A = +25°C, unless otherwise noted.)8109121115141316-400-2020406080SUPPLY CURRENTvs. TEMPERATURE (NO LOAD)TEMPERATURE (°C)S U P P L Y C U R R E N T (µA )0.20.60.40.81.01.2BATTERY SUPPLY CURRENT (BACKUP MODE) vs. TEMPERATURETEMPERATURE (°C)B A T T E R Y S U P P L YC U R R E N T (µA )-402040-200608021437658-40-2020406080BATT-TO-OUT ON-RESISTANCEvs. TEMPERATURETEMPERATURE (°C)B A T T -T O -O U T O N -R E S I S T A NC E (Ω)ELECTRICAL CHARACTERISTICS (continued)(V= +2.4V to +5.5V, V = +3.0V, CE IN = V , reset not asserted, T = -40°C to +85°C. Typical values are at T = +25°C,Note 2:V BATT can be 0 anytime, or V CC can go down to 0 if V BATT is active (except at startup).Note 3:RESET is pulled up to OUT. Specifications apply for OUT = V CC or OUT = BATT.Note 4:The chip-enable resistance is tested with V CC = V TH(MAX)and CE IN = V CC /2.MAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating_______________________________________________________________________________________5Typical Operating Characteristics (continued)(T A = +25°C, unless otherwise noted.)00.40.20.80.61.21.01.4-4020-20406080V CC TO OUT ON-RESISTANCEvs. TEMPERATURETEMPERATURE (°C)V C C T O O U T O N -R E S I S T A N C E (Ω)190195205200210RESET TIMEOUT PERIOD vs. TEMPERATUREM A X 6365/8-05TEMPERATURE (°C)R E S E T T I M E O U T P E R I O D (m s )-402040-206080301575604513512010590TEMPERATURE (°C)P R O P A G A T I O N D E L A Y (µs )-402040-206080V CC vs. TEMPERATURE2.03.02.55.04.54.03.5RESET THRESHOLD vs. TEMPERATURETEMPERATURE (°C)T H R E S H O L D (V )-402040-206080110010100010,000MAXIMUM TRANSIENT DURATION vs. RESET THRESHOLD OVERDRIVERESET THRESHOLD OVERDRIVE V TH - V CC (mV)M A X I M U M T R A N S I E N T D U R A T I O N (µs )40030035025020005015010003215498761000.5 1.0 1.5 2.0 2.5 3.0 3.5BATTERY SUPPLY CURRENT vs. SUPPLY VOLTAGEV CC (V)B A T T E R Y S U P P L YC U R R E N T (µA )M A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating 6_______________________________________________________________________________________1.2341.2351.236MAX6368RESET IN THRESHOLD vs. TEMPERATUREM A X 6365/8 -10TEMPERATURE (°C)V R T H (V )-402040-2060801.01.91.61.32.82.52.2MAX6368RESET IN TO RESET PROPAGATION DELAYvs. TEMPERATURETEMPERATURE (°C)P R O P A G A T I O N D E L A Y (µs )-402040-206080013245C LOAD (pF)P R O P A G A T I O N D E L A Y (n s )10050150200CHIP-ENABLE PROPAGATION DELAY vs. CE OUT LOAD CAPACITANCE515102025-40-2020406080TEMPERATURE (°C)C E I N T O C E O U T O N -R E S I S T A N C E (Ω)CE IN TO CE OUT ON-RESISTANCEvs. TEMPERATURE1.01.31.21.11.51.41.91.81.71.62.0-40-2020406080TEMPERATURE (°C)W A T C H D O G T I M E O U T P E R I O D (s )MAX6366WATCHDOG TIMEOUT PERIODvs. TEMPERATURETypical Operating Characteristics (continued)(T A = +25°C, unless otherwise noted.)MAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating_______________________________________________________________________________________7M A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating 8_______________________________________________________________________________________Detailed DescriptionThe Typical Operating Circuit shows a typical connec-tion for the MAX6365–MAX6368. OUT powers the static random-access memory (SRAM). If V CC is greater than the reset threshold (V TH ), or if V CC is lower than V TH but higher than V BATT , V CC is connected to OUT. If V CC is lower than V TH and V CC is less than V BATT ,BATT is connected to OUT. OUT supplies up to 150mA from V CC . In battery-backup mode, an internal MOSFET connects the backup battery to OUT. The on-resistance of the MOSFET is a function of backup-battery voltage and is shown in the BATT-to-OUT On-Resistance vs.Temperature graph in the T ypical Operating Char-acteristics .Chip-Enable Signal GatingThe MAX6365–MAX6368 provide internal gating of CE signals to prevent erroneous data from being written toCMOS RAM in the event of a power failure. During nor-mal operation, the CE gate is enabled and passes all CE transitions. When reset asserts, this path becomes disabled, preventing erroneous data from corrupting the CMOS RAM. All of these devices use a series trans-mission gate from CE IN to CE OUT. The 2ns propaga-tion delay from CE IN to CE OUT allows the devices to be used with most µPs and high-speed DSPs.During normal operation, CE IN is connected to CE OUT through a low on-resistance transmission gate.This is valid when reset is not asserted. If CE IN is high when reset is asserted, CE OUT remains high regard-less of any subsequent transitions on CE IN during the reset event.If CE IN is low when reset is asserted, CE OUT is held low for 12µs to allow completion of the read/write oper-ation (F igure 1). After the 12µs delay expires, the CEFunctional DiagramMAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating_______________________________________________________________________________________9OUT goes high and stays high regardless of any sub-sequent transitions on CE IN during the reset event.When CE OUT is disconnected from CE IN, CE OUT is actively pulled up to OUT.The propagation delay through the chip-enable circuit-ry depends on both the source impedance of the drive to CE IN and the capacitive loading at CE OUT. The chip-enable propagation delay is production tested from the 50% point of CE IN to the 50% point of CE OUT, using a 50Ωdriver and 50pF load capacitance.Minimize the capacitive load at CE OUT to minimize propagation delay, and use a low-output-impedance driver.Backup-Battery SwitchoverIn a brownout or power failure, it may be necessary to preserve the contents of the RAM. With a backup bat-tery installed at BATT, the MAX6365–MAX6368 auto-matically switch the RAM to backup power when V CC falls. The MAX6367 has a BATT ON output that goes high in battery-backup mode. These devices require two conditions before switching to battery-backup mode:1) V CC must be below the reset threshold.2) V CC must be below V BATT .Table 1 lists the status of the inputs and outputs in bat-tery-backup mode. The devices do not power up if theonly voltage source is on BATT. OUT only powers up from V CC at startup.Many µP-based products require manual reset capabili-ty, allowing the user or external logic circuitry to initiate a reset. For the MAX6365, a logic low on MR asserts reset.Reset remains asserted while MR is low and for a mini-mum of 150ms (t RP ) after it returns high. MR has an inter-nal 20k Ωpullup resistor to V CC . This input can be driven with TTL/CMOS logic levels or with open-drain/collector outputs. Connect a normally open momentary switch from MR to GND to create a manual reset function; exter-nal debounce circuitry is not required. If MR is driven from long cables or the device is used in a noisy environ-ment, connect a 0.1µF capacitor from MR to GND to pro-vide additional noise immunity.Figure 1. Reset and Chip-Enable TimingM A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating 10______________________________________________________________________________________Watchdog Input (MAX6366 Only)The watchdog monitors µP activity through the watch-dog input (WDI). If the µP becomes inactive, reset asserts. To use the watchdog function, connect WDI to a bus line or µP I/O line. A change of state (high to low,low to high, or a minimum 100ns pulse) resets the watchdog timer. If WDI remains high or low for longer than the watchdog timeout period (t WD ), the internal watchdog timer runs out and a reset pulse is triggered for the reset timeout period (t RP ). The internal watchdog timer clears whenever reset asserts or whenever WDI sees a rising or falling edge. If WDI remains in either a high or low state, a reset pulse asserts periodically after every t WD (F igure 2). Leave WDI unconnected to dis-able the watchdog function.BATT ON Indicator (MAX6367 Only)BATT ON is a push-pull output that drives high when in battery-backup mode. BATT ON typically sinks 3.2mA at 0.1V saturation voltage. In battery-backup mode, this terminal sources approximately 10µA from OUT. Use BATT ON to indicate battery-switchover status or to supply base drive to an external pass transistor for higher current applications (Figure 3).RESET IN Comparator (MAX6368 Only)RESET IN is compared to an internal 1.235V reference.If the voltage at RESET IN is less than 1.235V, reset asserts. Use the RESET IN comparator as an undervolt-age detector to signal a failing power supply or as a secondary power-supply reset monitor.To program the reset threshold (V RTH ) of the secondary power supply, use the following (see Typical Operating Circuit ):V RTH = V REF (R1 / R2 + 1)where V REF = 1.235V. To simplify the resistor selection,choose a value for R2 and calculate R1:R1 = R2 [(V RTH / V REF ) - 1]Since the input current at RESET IN is 25nA (max),large values (up to 1M Ω) can be used for R2 with no significant loss in accuracy. For example, in the Typical Operating Circuit , the MAX6368 monitors two supply voltages. To monitor the secondary 5V logic or analog supply with a 4.60V nominal programmed reset thresh-old, choose R2 = 100k Ω, and calculate R1 = 273k Ω.Reset OutputA µP ’s reset input starts the µP in a known state. The MAX6365–MAX6368 µP supervisory circuits assert a reset to prevent code-execution errors during power-up, power-down, and brownout conditions. RESET is guaranteed to be a logic low or logic high, depending on the device chosen (see Ordering Information ).RESET or RESET asserts when V CC is below the reset threshold and for at least 150ms (t RP ) after V CC rises above the reset threshold. RESET or RESET also asserts when MR is low (MAX6365) and when RESET IN is less than 1.235V (MAX6368). The MAX6366 watch-dog function will cause RESET (or RESET ) to assert in pulses following a watchdog timeout (Figure 2).Applications InformationOperation Withouta Backup Power SourceThe MAX6365–MAX6368 provide battery-backup func-tions. If a backup power source is not used, connect BATT to GND and OUT to V CC .Watchdog Software ConsiderationsOne way to help the watchdog timer monitor the soft-ware execution more closely is to set and reset the watchdog at different points in the program rather than pulsing the watchdog input periodically. F igure 4shows a flow diagram in which the I/O driving theFigure 2. MAX6366 Watchdog Timeout Period and Reset Active TimeMAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating______________________________________________________________________________________11watchdog is set low in the beginning of the program,set high at the beginning of every subroutine or loop,and set low again when the program returns to the beginning. If the program should hang in any subrou-tine, the problem would be quickly corrected.Replacing the Backup BatteryWhen V CC is above V TH , the backup power source can be removed without danger of triggering a reset pulse.The device does not enter battery-backup mode when V CC stays above the reset threshold voltage.Negative-Going V CC TransientsThese supervisors are relatively immune to short-dura-tion, negative-going V CC transients. Resetting the µP when V CC experiences only small glitches is usually not desirable.The T ypical Operating Characteristics section has a Maximum Transient Duration vs. Reset Threshold Overdrive graph for which reset is not asserted. The graph was produced using negative-going V CC pulses,starting at V CC and ending below the reset threshold by the magnitude indicated (reset threshold overdrive).The graph shows the maximum pulse width that a neg-ative-going V CC transient can typically have without triggering a reset pulse. As the amplitude of the tran-sient increases (i.e., goes further below the reset threshold), the maximum allowable pulse width decreases. Typically, a V CC transient that goes 100mV below the reset threshold and lasts for 30µs will not trig-ger a reset pulse.A 0.1µF bypass capacitor mounted close to the V CC pin provides additional transient immunity.M A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating 12______________________________________________________________________________________standard versions only. Contact factory for availability of nonstandard versions.MAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating______________________________________________________________________________________13Pin Configurations (continued)M A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating 14______________________________________________________________________________________Typical Operating CircuitChip InformationTRANSISTOR COUNT: 729PROCESS: CMOSSOT23, Low-Power µP Supervisory Circuitswith Battery Backup and Chip-Enable GatingMAX6365–MAX6368Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________15©2001 Maxim Integrated Products Printed USAis a registered trademark of Maxim Integrated Products.Package Information。

For free samples & the latest literature: , or phone 1-800-998-8800.For small orders, phone 408-737-7600 ext. 3468.General DescriptionThe MAX6305–MAX6313 CMOS microprocessor (µP)supervisory circuits are designed to monitor more than one power supply. Ideal for monitoring both 5V and 3.3V in personal computer systems, these devicesFeatureso Small 5-Pin SOT23 Packageo Precision Factory-Set V CC Reset Thresholds;Available in 0.1V Increments from 2.5V to 5V o Immune to Short V TransientsMAX6305–MAX63135-Pin, Multiple-Input,Programmable Reset ICs________________________________________________________________Maxim Integrated Products 119-1145; Rev 1; 8/98M A X 6305–M A X 63135-Pin, Multiple-Input, Programmable Reset ICs 2_______________________________________________________________________________________ABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICSV CC = +2.5V to +5.5V for the MAX6305/MAX6308/MAX6311, V CC = (V TH + 2.5%) to +5.5V for the MAX6306/MAX6307/MAX6309/MAX6310/MAX6312/MAX6313; T A = 0°C to +70°C; unless otherwise noted. Typical values are at T A = +25°C.)Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.V CC ...........................................................................-0.3V to +6V All Other Pins..............................................-0.3V to (V CC + 0.3V)Input/Output Current, All Pins.............................................20mA Rate of Rise, V CC ............................................................100V/µsContinuous Power Dissipation (T A = +70°C)SOT23-5 (derate 7.1mW/°C above +70°C).................571mW Operating Temperature Range...............................0°C to +70°C Storage Temperature Range.............................-65°C to +160°C Lead Temperature (soldering, 10sec).............................+300°CMAX6305–MAX63135-Pin, Multiple-Input, Programmable Reset ICs_______________________________________________________________________________________3ELECTRICAL CHARACTERISTICS (continued)(V CC = +2.5V to +5.5V for the MAX6305/MAX6308/MAX6311, V CC = (V TH + 2.5%) to +5.5V for the MAX6306/MAX6307/MAX6309/MAX6310/MAX6312/MAX6313; T A = 0°C to +70°C; unless otherwise noted. Typical values are at T A = +25°C.)Note 1: The MAX6305/MAX6308/MAX6311 switch from undervoltage reset to normal operation between 1.5V < V CC < 2.5V.Note 2: The MAX6306/MAX6307/MAX6309/MAX6310/MAX6312/MAX6313 monitor V CC through an internal factory-trimmed voltagedivider, which programs the nominal reset threshold. Factory-trimmed reset thresholds are available in approximately 100mV increments from 2.5V to 5V (Table 1).M A X 6305–M A X 63135-Pin, Multiple-Input, Programmable Reset ICs 4_________________________________________________________________________________________________________________________________Typical Operating Characteristics(V CC = +5V, T A = +25°C, unless otherwise noted.)5.05.56.06.57.07.58.08.59.09.5-60-40-2020406080100SUPPLY CURRENT vs. TEMPERATURETEMPERATURE (°C)S U P P L Y C U R R E N T (µA )01020304050607080-60-40-2020406080100V CC FALLING PROPAGATION DELAYvs. TEMPERATURETEMPERATURE (°C)P R O P A G A T I O N D E L A Y (n s )010203040506070-60-40-20020406080100OVRST IN RISING PROPAGATION DELAY vs. TEMPERATURE (OVERVOLTAGE RESET INPUT)TEMPERATURE (°C)P R O P A G A T I O N D E L A Y (n s )020406080100120-60-40-2020406080100RST IN_ FALLING PROPAGATION DELAY vs. TEMPERATURETEMPERATURE (°C)R S T I N _ P R O P A G A T I O N D E L A Y (n s )104001200800MAXIMUM TRANSIENT DURATION vs.V CC RESET THRESHOLD OVERDRIVE10OVERDRIVE, V TH - V CC (mV)T R A N S I E N T D U R A T I O N (µs )100100010,0000.900.920.940.960.981.001.021.041.061.081.10-60-40-20020406080100RESET TIMEOUT vs. TEMPERATURE6305 T O C 05TEMPERATURE (°C)N O R M A L I Z E D R E S E T T I M E O U T0.9900.9920.9940.9960.9981.0001.0021.0041.0061.0081.010-60-40-2020406080100RESET THRESHOLD vs. TEMPERATURE6305 T O C 06TEMPERATURE (°C)N O R M A L I Z E D R E S E T T H R E S H O L D (V /V )104001200800MAXIMUM TRANSIENT DURATION vs.OVRST IN THRESHOLD OVERDRIVE10OVERDRIVE, V OVRST IN - V REF (mV)T R A N S I E N T D U R A T I O N (µs )100100010,000104001200800MAXIMUM TRANSIENT DURATION vs.RST IN_ THRESHOLD OVERDRIVE10OVERDRIVE, V REF - V RST IN (mV)T R A N S I E N T D U R A T I O N (µs )100100010,000_______________Detailed DescriptionThe MAX6305–MAX6313 CMOS microprocessor (µP)supervisory circuits are designed to monitor more than one power supply and issue a system reset when any monitored supply falls out of regulation. The MAX6305/MAX6308/MAX6311 have two adjustable undervoltage reset inputs (RST IN1 and RST IN2). The MAX6306/MAX6307/MAX6309/MAX6310/MAX6312/MAX6313 mon-itor V CC through an internal, factory-trimmed voltage divider. The MAX6306/MAX6309/MAX6312 have, in addition, an adjustable undervoltage reset input and a manual-reset input. The internal voltage divider sets the reset threshold as specified in the device part number (Table 1). The MAX6307/MAX6310/ MAX6313 feature an adjustable undervoltage reset input (RST IN) and an adjustable overvoltage reset input (OVRST IN) in addition to the factory-trimmed reset threshold on the V CC moni-tor. Program the adjustable reset inputs with an external resistor divider (see Adjustable Reset Inputs section).Reset OutputsA µP’s reset input starts the µP in a known state. These µP supervisory circuits assert reset to prevent code-execution errors during power-up, power-down, or brownout conditions.RESET (MAX6305–MAX6310) and RESET (MAX6311/MAX6312/MAX6313) are guaranteed to be asserted at a valid logic level for V CC > 1V (see Electrical Characteristics ). Once all monitored voltages exceed their programmed reset thresholds, an internal timer keeps reset asserted for the reset timeout period (t RP );after this interval, reset deasserts.If a brownout condition occurs (any or all monitored volt-ages dip outside their programmed reset threshold),reset asserts (RESET goes high; RESET goes low). Any time any of the monitored voltages dip below their reset threshold, the internal timer resets to zero and reset asserts. The internal timer starts when all of the moni-tored voltages return above their reset thresholds, and reset remains asserted for a reset timeout period. The MAX6305/MAX6306/MAX6307 feature an active-low,MAX6305–MAX63135-Pin, Multiple-Input, Programmable Reset ICs_______________________________________________________________________________________5______________________________________________________________Pin DescriptionM A X 6305–M A X 6313open-drain, N-channel output. The MAX6308/MAX6309/MAX6310 feature an active-low, complementary output structure that both sinks and sources current, and the MAX6311/MAX6312/MAX6313 have an active-high com-plementary reset output.The MAX6305/MAX6308/MAX6311 switch from under-voltage lockout operation to normal operation between 1.5V < V CC < 2.5V. Below 1.5V, V CC undervoltage-lockout mode asserts RESET . Above 2.5V, V CC normal-operation mode asserts reset if RST IN_ falls below the RST IN_ threshold.Manual-Reset Input(MAX6306/MAX6309/MAX6312)Many µP-based products require manual-reset capability,allowing an operator or external logic circuitry to initiate a reset. A logic low on MR asserts reset. Reset remains asserted while MR is low, and for a reset active timeout period (t RP ) after MR returns high. This input has an inter-nal 63.5k Ωpull-up resistor, so it can be left open if it is not used. MR can be driven with TTL-logic levels in 5V sys-tems, with CMOS-logic levels in 3V systems, or with open-drain/collector output devices. Connect a normally open momentary switch from MR to GND to create a manual-reset function; external debounce circuitry is not required.If MR is driven from long cables or if the device is used in a noisy environment, connecting a 0.1µF capacitor from MR to ground provides additional noise immunity.The MR pin has internal ESD-protection circuitry that may be forward biased under certain conditions, drawing excessive current. For example, assume the circuitry driv-ing MR uses a +5V supply other than V CC . If V CC drops or browns out lower than +4.7V, MR ’s absolute maximum rat-ing is violated (-0.3V to (V CC + 0.3V)), and undesirable current flows through the ESD structure from MR to V CC .To avoid this, it is recommended that the supply for the MR pin be the same as the supply monitored by V CC . In this way, the voltage at MR will not exceed V CC .Adjustable Reset InputsThe MAX6305–MAX6313 each have one or more reset inputs (RST IN_ /OVRST IN). These inputs are com-pared to the internal reference voltage (Figure 1).Connect a resistor voltage divider to RST IN_ such that V RST IN_falls below V RSTH (1.23V) when the monitored voltage (V IN ) falls below the desired reset threshold (V TH ) (Figure 2). Calculate the desired reset voltage with the following formula:R1 + R2V TH = ________x V RSTHR25-Pin, Multiple-Input, Programmable Reset ICs 6_______________________________________________________________________________________Figure 1. Functional DiagramMAX6305–MAX63135-Pin, Multiple-Input, Programmable Reset ICs_______________________________________________________________________________________7The ±25nA max input leakage current allows resistors on the order of megohms. Choose the pull-up resistor in the divider to minimize the error due to the input leakage cur-rent. The error term in the calculated threshold is simply:±25nA x R1If you choose R1 to be 1M Ω, the resulting error is ±25 x 10-9x 1 x 106= ±25mV.Like the V CC voltage monitors on the MAX6306/MAX6307/MAX6309/MAX6310/MAX6312/MAX6313, the RST IN_inputs (when used with a voltage divider) are designed to ignore fast voltage transients. Increase the noise immunity by connecting a capacitor on the order of 0.1µF between RST IN and GND (Figure 2). This creates a single-pole lowpass filter with a corner frequency given by:f = (1/2π) / (R1 + R2)(R1 x R2 x C)For example, if R1 = 1M Ωand R2 = 1.6M Ω, adding a 0.1µF capacitor from RST IN_ to ground results in a lowpass corner frequency of f = 2.59Hz. Note that adding capacitance to RST IN slows the circuit’s overall response time.__________Applications InformationInterfacing to µPs with Bidirectional Reset PinsSince the RESET output on the MAX6305/MAX6306/MAX6307 is open drain, these devices interface easily with µPs that have bidirectional reset pins, such as the Motorola 68HC11. Connecting the µP supervisor’s RESET output directly to the microcontroller’s RESET pin with a single pull-up resistor allows either device to assert reset (Figure 3).Negative-Going V CC TransientsIn addition to issuing a reset to the µP during power-up,power-down, and brownout conditions, these devices are relatively immune to short-duration, negative-going V CC transients (glitches).The Typical Operating Characteristics show the Maximum Transient Duration vs. V CC Reset Threshold Overdrive, for which reset pulses are not generated.The graph was produced using negative-going pulses,starting at V TH max, and ending below the pro-grammed reset threshold by the magnitude indicated (reset threshold overdrive). The graph shows the maxi-mum pulse width that a negative-going V CC transient may typically have without causing a reset pulse to be issued. As the amplitude of the transient increases (i.e.,goes farther below the reset threshold), the maximum allowable pulse width decreases.RST IN_/OVRST IN are also immune to negative/positive-going transients (see Typical Operating Characteristics ).A 0.1µF bypass capacitor mounted close to the RST IN_,OVRST IN, and/or the V CC pin provides additional tran-sient immunity.Ensuring a Valid RESET /RESETOutput Down to V CC = 0VWhen V CC falls below 1V, push/pull structured RESET /RESET current sinking (or sourcing) capabilities decrease drastically. High-impedance CMOS-logic inputs connected to RESET can drift to undetermined voltages. This presents no problem in most applica-tions, since most µPs and other circuitry do not operate with V CC below 1V. In those applications where RESET must be valid down to 0V, adding a pull-down resistor between RESET and ground sinks any stray leakageFigure 2. Increasing Noise ImmunityFigure 3. Interfacing to µPs with Bidirectional Reset I/Ocurrents, holding RESET low (Figure 4). The pull-down resistor’s value is not critical; 100k Ωis large enough not to load RESET and small enough to pull RESET to ground. For applications where RESET must be valid to V CC , a 100k Ωpull-up resistor between RESET and V CC will hold RESET high when V CC falls below 1V (Figure 5).Since the MAX6305/MAX6306/MAX6307 have open-drain, active-low outputs, they typically use a pull-up resistor. With these devices and under these conditions (V CC < 1V), RESET will most likely not maintain an active condition, but will drift toward a nonactive level due to the pull-up resistor and the RESET output’s reduction in sinking capability. These devices are not recommended for applications that require a valid RESET output below 1V.* Factory-trimmed reset thresholds are available in approximately 100mV increments with a ±1.5% room-temperature variance.M A X 6305–M A X 63135-Pin, Multiple-Input, Programmable Reset ICs 8_______________________________________________________________________________________Figure 4. Ensuring RESET Valid to V CC = 0VFigure 5. Ensuring RESET Valid to V CC = 0VTable 1. Factory-Trimmed Reset Thresholds *MAX6305UK00D1-T ABAK MAX6306UK41D3-T ABCA MAX6306UK30D1-T ABDQ MAX6307UK46D3-T ABFG MAX6305UK00D2-T ABAL MAX6306UK41D4-T ABCB MAX6306UK30D2-T ABDR MAX6307UK46D4-T ABFH MAX6305UK00D3-T ABAM MAX6306UK40D1-T ABCC MAX6306UK30D3-T ABDS MAX6307UK45D1-T ABFI MAX6305UK00D4-T ABAN MAX6306UK40D2-T ABCD MAX6306UK30D4-T ABDT MAX6307UK45D2-T ABFJ MAX6306UK50D1-T ABAO MAX6306UK40D3-T ABCE MAX6306UK29D1-T ABDU MAX6307UK45D3-T ABFK MAX6306UK50D2-T ABAP MAX6306UK40D4-T ABCF MAX6306UK29D2-T ABDV MAX6307UK45D4-T ABFL MAX6306UK50D3-T ABAQ MAX6306UK39D1-T ABCG MAX6306UK29D3-T ABDW MAX6307UK44D1-T ABFM MAX6306UK50D4-T ABAR MAX6306UK39D2-T ABCH MAX6306UK29D4-T ABDX MAX6307UK44D2-T ABFN MAX6306UK49D1-T ABAS MAX6306UK39D3-T ABCI MAX6306UK28D1-T ABDY MAX6307UK44D3-T ABFO MAX6306UK49D2-T ABAT MAX6306UK39D4-T ABCJ MAX6306UK28D2-T ABDZ MAX6307UK44D4-T ABFP MAX6306UK49D3-T ABAU MAX6306UK38D1-T ABCK MAX6306UK28D3-T ABEA MAX6307UK43D1-T ABFQ MAX6306UK49D4-T ABAV MAX6306UK38D2-T ABCL MAX6306UK28D4-T ABEB MAX6307UK43D2-T ABFR MAX6306UK48D1-T ABAW MAX6306UK38D3-T ABCM MAX6306UK27D1-T ABEC MAX6307UK43D3-T ABFS MAX6306UK48D2-T ABAX MAX6306UK38D4-T ABCN MAX6306UK27D2-T ABED MAX6307UK43D4-T ABFT MAX6306UK48D3-T ABAY MAX6306UK37D1-T ABCO MAX6306UK27D3-T ABEE MAX6307UK42D1-T ABFU MAX6306UK48D4-T ABAZ MAX6306UK37D2-T ABCP MAX6306UK27D4-T ABEF MAX6307UK42D2-T ABFV MAX6306UK47D1-T ABBA MAX6306UK37D3-T ABCQ MAX6306UK26D1-T ABEG MAX6307UK42D3-T ABFW MAX6306UK47D2-T ABBB MAX6306UK37D4-T ABCR MAX6306UK26D2-T ABEH MAX6307UK42D4-T ABFX MAX6306UK47D3-T ABBC MAX6306UK36D1-T ABCS MAX6306UK26D3-T ABEI MAX6307UK41D1-T ABFY MAX6306UK47D4-T ABBD MAX6306UK36D2-T ABCT MAX6306UK26D4-T ABEJ MAX6307UK41D2-T ABFZ MAX6306UK46D1-T ABBE MAX6306UK36D3-T ABCU MAX6306UK25D1-T ABEK MAX6307UK41D3-T ABGA MAX6306UK46D2-T ABBF MAX6306UK36D4-T ABCV MAX6306UK25D2-T ABEL MAX6307UK41D4-T ABGB MAX6306UK46D3-T ABBG MAX6306UK35D1-T ABCW MAX6306UK25D3-T ABEM MAX6307UK40D1-T ABGC MAX6306UK46D4-T ABBH MAX6306UK35D2-T ABCX MAX6306UK25D4-T ABEN MAX6307UK40D2-T ABGD MAX6306UK45D1-T ABBI MAX6306UK35D3-T ABCY MAX6307UK50D1-T ABEO MAX6307UK40D3-T ABGE MAX6306UK45D2-T ABBJ MAX6306UK35D4-T ABCZ MAX6307UK50D2-T ABEP MAX6307UK40D4-T ABGF MAX6306UK45D3-T ABBK MAX6306UK34D1-T ABDA MAX6307UK50D3-T ABEQ MAX6307UK39D1-T ABGG MAX6306UK45D4-T ABBL MAX6306UK34D2-T ABDB MAX6307UK50D4-T ABER MAX6307UK39D2-T ABGH MAX6306UK44D1-T ABBM MAX6306UK34D3-T ABDC MAX6307UK49D1-T ABES MAX6307UK39D3-T ABGI MAX6306UK44D2-T ABBN MAX6306UK34D4-T ABDD MAX6307UK49D2-T ABET MAX6307UK39D4-T ABGJ MAX6306UK44D3-T ABBO MAX6306UK33D1-T ABDE MAX6307UK49D3-T ABEU MAX6307UK38D1-T ABGK MAX6306UK44D4-T ABBP MAX6306UK33D2-T ABDF MAX6307UK49D4-T ABEV MAX6307UK38D2-T ABGL MAX6306UK43D1-T ABBQ MAX6306UK33D3-T ABDG MAX6307UK48D1-T ABEW MAX6307UK38D3-T ABGM MAX6306UK43D2-T ABBR MAX6306UK33D4-T ABDH MAX6307UK48D2-T ABEX MAX6307UK38D4-T ABGN MAX6306UK43D3-T ABBS MAX6306UK32D1-T ABDI MAX6307UK48D3-T ABEY MAX6307UK37D1-T ABGO MAX6306UK43D4-T ABBT MAX6306UK32D2-T ABDJ MAX6307UK48D4-T ABEZ MAX6307UK37D2-T ABGP MAX6306UK42D1-T ABBU MAX6306UK32D3-T ABDK MAX6307UK47D1-T ABFA MAX6307UK37D3-T ABGQ MAX6306UK42D2-T ABBV MAX6306UK32D4-T ABDL MAX6307UK47D2-T ABFB MAX6307UK37D4-T ABGR MAX6306UK42D3-T ABBW MAX6306UK31D1-T ABDM MAX6307UK47D3-T ABFC MAX6307UK36D1-T ABGS MAX6306UK42D4-T ABBX MAX6306UK31D2-T ABDN MAX6307UK47D4-T ABFD MAX6307UK36D2-T ABGT MAX6306UK41D1-T ABBY MAX6306UK31D3-T ABDO MAX6307UK46D1-T ABFE MAX6307UK36D3-T ABGU MAX6306UK41D2-TABBZMAX6306UK31D4-TABDPMAX6307UK46D2-TABFFMAX6307UK36D4-TABGVMAX6305–MAX63135-Pin, Multiple-Input, Programmable Reset ICs_______________________________________________________________________________________9Table 2. Device Marking CodesDEVICECODE DEVICECODE DEVICECODE DEVICECODEM A X 6305–M A X 63135-Pin, Multiple-Input, Programmable Reset ICs 10______________________________________________________________________________________Table 2. Device Marking Codes (continued)MAX6307UK35D1-T ABGW MAX6307UK25D3-T ABIM MAX6309UK41D1-T ABKC MAX6309UK31D3-T ABLS MAX6307UK35D2-T ABGX MAX6307UK25D4-T ABIN MAX6309UK41D2-T ABKD MAX6309UK31D4-T ABLT MAX6307UK35D3-T ABGY MAX6308UK00D1-T ABIO MAX6309UK41D3-T ABKE MAX6309UK30D1-T ABLU MAX6307UK35D4-T ABGZ MAX6308UK00D2-T ABIP MAX6309UK41D4-T ABKF MAX6309UK30D2-T ABLV MAX6307UK34D1-T ABHA MAX6308UK00D3-T ABIQ MAX6309UK40D1-T ABKG MAX6309UK30D3-T ABLW MAX6307UK34D2-T ABHB MAX6308UK00D4-T ABIR MAX6309UK40D2-T ABKH MAX6309UK30D4-T ABLX MAX6307UK34D3-T ABHC MAX6309UK50D1-T ABIS MAX6309UK40D3-T ABKI MAX6309UK29D1-T ABLY MAX6307UK34D4-T ABHD MAX6309UK50D2-T ABIT MAX6309UK40D4-T ABKJ MAX6309UK29D2-T ABLZ MAX6307UK33D1-T ABHE MAX6309UK50D3-T ABIU MAX6309UK39D1-T ABKK MAX6309UK29D3-T ABMA MAX6307UK33D2-T ABHF MAX6309UK50D4-T ABIV MAX6309UK39D2-T ABKL MAX6309UK29D4-T ABMB MAX6307UK33D3-T ABHG MAX6309UK49D1-T ABIW MAX6309UK39D3-T ABKM MAX6309UK28D1-T ABMC MAX6307UK33D4-T ABHH MAX6309UK49D2-T ABIX MAX6309UK39D4-T ABKN MAX6309UK28D2-T ABMD MAX6307UK32D1-T ABHI MAX6309UK49D3-T ABIY MAX6309UK38D1-T ABKO MAX6309UK28D3-T ABME MAX6307UK32D2-T ABHJ MAX6309UK49D4-T ABIZ MAX6309UK38D2-T ABKP MAX6309UK28D4-T ABMF MAX6307UK32D3-T ABHK MAX6309UK48D1-T ABJA MAX6309UK38D3-T ABKQ MAX6309UK27D1-T ABMG MAX6307UK32D4-T ABHL MAX6309UK48D2-T ABJB MAX6309UK38D4-T ABKR MAX6309UK27D2-T ABMH MAX6307UK31D1-T ABHM MAX6309UK48D3-T ABJC MAX6309UK37D1-T ABKS MAX6309UK27D3-T ABMI MAX6307UK31D2-T ABHN MAX6309UK48D4-T ABJD MAX6309UK37D2-T ABKT MAX6309UK27D4-T ABMJ MAX6307UK31D3-T ABHO MAX6309UK47D1-T ABJE MAX6309UK37D3-T ABKU MAX6309UK26D1-T ABMK MAX6307UK31D4-T ABHP MAX6309UK47D2-T ABJF MAX6309UK37D4-T ABKV MAX6309UK26D2-T ABML MAX6307UK30D1-T ABHQ MAX6309UK47D3-T ABJG MAX6309UK36D1-T ABKW MAX6309UK26D3-T ABMM MAX6307UK30D2-T ABHR MAX6309UK47D4-T ABJH MAX6309UK36D2-T ABKX MAX6309UK26D4-T ABMN MAX6307UK30D3-T ABHS MAX6309UK46D1-T ABJI MAX6309UK36D3-T ABKY MAX6309UK25D1-T ABMO MAX6307UK30D4-T ABHT MAX6309UK46D2-T ABJJ MAX6309UK36D4-T ABKZ MAX6309UK25D2-T ABMP MAX6307UK29D1-T ABHU MAX6309UK46D3-T ABJK MAX6309UK35D1-T ABLA MAX6309UK25D3-T ABMQ MAX6307UK29D2-T ABHV MAX6309UK46D4-T ABJL MAX6309UK35D2-T ABLB MAX6309UK25D4-T ABMR MAX6307UK29D3-T ABHW MAX6309UK45D1-T ABJM MAX6309UK35D3-T ABLC MAX6310UK50D1-T ABMS MAX6307UK29D4-T ABHX MAX6309UK45D2-T ABJN MAX6309UK35D4-T ABLD MAX6310UK50D2-T ABMT MAX6307UK28D1-T ABHY MAX6309UK45D3-T ABJO MAX6309UK34D1-T ABLE MAX6310UK50D3-T ABMU MAX6307UK28D2-T ABHZ MAX6309UK45D4-T ABJP MAX6309UK34D2-T ABLF MAX6310UK50D4-T ABMV MAX6307UK28D3-T ABIA MAX6309UK44D1-T ABJQ MAX6309UK34D3-T ABLG MAX6310UK49D1-T ABMW MAX6307UK28D4-T ABIB MAX6309UK44D2-T ABJR MAX6309UK34D4-T ABLH MAX6310UK49D2-T ABMX MAX6307UK27D1-T ABIC MAX6309UK44D3-T ABJS MAX6309UK33D1-T ABLI MAX6310UK49D3-T ABMY MAX6307UK27D2-T ABID MAX6309UK44D4-T ABJT MAX6309UK33D2-T ABLJ MAX6310UK49D4-T ABMZ MAX6307UK27D3-T ABIE MAX6309UK43D1-T ABJU MAX6309UK33D3-T ABLK MAX6310UK48D1-T ABNA MAX6307UK27D4-T ABIF MAX6309UK43D2-T ABJV MAX6309UK33D4-T ABLL MAX6310UK48D2-T ABNB MAX6307UK26D1-T ABIG MAX6309UK43D3-T ABJW MAX6309UK32D1-T ABLM MAX6310UK48D3-T ABNC MAX6307UK26D2-T ABIH MAX6309UK43D4-T ABJX MAX6309UK32D2-T ABLN MAX6310UK48D4-T ABND MAX6307UK26D3-T ABII MAX6309UK42D1-T ABJY MAX6309UK32D3-T ABLO MAX6310UK47D1-T ABNE MAX6307UK26D4-T ABIJ MAX6309UK42D2-T ABJZ MAX6309UK32D4-T ABLP MAX6310UK47D2-T ABNF MAX6307UK25D1-T ABIK MAX6309UK42D3-T ABKA MAX6309UK31D1-T ABLQ MAX6310UK47D3-T ABNG MAX6307UK25D2-TABILMAX6309UK42D4-TABKBMAX6309UK31D2-TABLRMAX6310UK47D4-TABNHDEVICECODE DEVICECODE DEVICECODE DEVICECODEMAX6305–MAX6313Programmable Reset ICs______________________________________________________________________________________11Table 2. Device Marking Codes (continued)MAX6310UK46D1-T ABNI MAX6310UK36D3-T ABOY MAX6310UK25D1-T ABQO MAX6312UK42D3-T ABSE MAX6310UK46D2-T ABNJ MAX6310UK36D4-T ABOZ MAX6310UK25D2-T ABQP MAX6312UK42D4-T ABSF MAX6310UK46D3-T ABNK MAX6310UK35D1-T ABPA MAX6310UK25D3-T ABQQ MAX6312UK41D1-T ABSG MAX6310UK46D4-T ABNL MAX6310UK35D2-T ABPB MAX6310UK25D4-T ABQR MAX6312UK41D2-T ABSH MAX6310UK45D1-T ABNM MAX6310UK35D3-T ABPC MAX6311UK00D1-T ABQS MAX6312UK41D3-T ABSI MAX6310UK45D2-T ABNN MAX6310UK35D4-T ABPD MAX6311UK00D2-T ABQT MAX6312UK41D4-T ABSJ MAX6310UK45D3-T ABNO MAX6310UK34D1-T ABPE MAX6311UK00D3-T ABQU MAX6312UK40D1-T ABSK MAX6310UK45D4-T ABNP MAX6310UK34D2-T ABPF MAX6311UK00D4-T ABQV MAX6312UK40D2-T ABSL MAX6310UK44D1-T ABNQ MAX6310UK34D3-T ABPG MAX6311UK50D1-T ABQW MAX6312UK40D3-T ABSM MAX6310UK44D2-T ABNR MAX6310UK34D4-T ABPH MAX6312UK50D2-T ABQX MAX6312UK40D4-T ABSN MAX6310UK44D3-T ABNS MAX6310UK33D1-T ABPI MAX6312UK50D3-T ABQY MAX6312UK39D1-T ABSO MAX6310UK44D4-T ABNT MAX6310UK33D2-T ABPJ MAX6312UK50D4-T ABQZ MAX6312UK39D2-T ABSP MAX6310UK43D1-T ABNU MAX6310UK33D3-T ABPK MAX6312UK49D1-T ABRA MAX6312UK39D3-T ABSQ MAX6310UK43D2-T ABNV MAX6310UK33D4-T ABPL MAX6312UK49D2-T ABRB MAX6312UK39D4-T ABSR MAX6310UK43D3-T ABNW MAX6310UK32D1-T ABPM MAX6312UK49D3-T ABRC MAX6312UK38D1-T ABSS MAX6310UK43D4-T ABNX MAX6310UK32D2-T ABPN MAX6312UK49D4-T ABRD MAX6312UK38D2-T ABST MAX6310UK42D1-T ABNY MAX6310UK32D3-T ABPO MAX6312UK48D1-T ABRE MAX6312UK38D3-T ABSU MAX6310UK42D2-T ABNZ MAX6310UK32D4-T ABPP MAX6312UK48D2-T ABRF MAX6312UK38D4-T ABSV MAX6310UK42D3-T ABOA MAX6310UK31D1-T ABPQ MAX6312UK48D3-T ABRG MAX6312UK37D1-T ABSW MAX6310UK42D4-T ABOB MAX6310UK31D2-T ABPR MAX6312UK48D4-T ABRH MAX6312UK37D2-T ABSX MAX6310UK41D1-T ABOC MAX6310UK31D3-T ABPS MAX6312UK47D1-T ABRI MAX6312UK37D3-T ABSY MAX6310UK41D2-T ABOD MAX6310UK31D4-T ABPT MAX6312UK47D2-T ABRJ MAX6312UK37D4-T ABSZ MAX6310UK41D3-T ABOE MAX6310UK30D1-T ABPU MAX6312UK47D3-T ABRK MAX6312UK36D1-T ABTA MAX6310UK41D4-T ABOF MAX6310UK30D2-T ABPV MAX6312UK47D4-T ABRL MAX6312UK36D2-T ABTB MAX6310UK40D1-T ABOG MAX6310UK30D3-T ABPW MAX6312UK46D1-T ABRM MAX6312UK36D3-T ABTC MAX6310UK40D2-T ABOH MAX6310UK30D4-T ABPX MAX6312UK46D2-T ABRN MAX6312UK36D4-T ABTD MAX6310UK40D3-T ABOI MAX6310UK29D1-T ABPY MAX6312UK46D3-T ABRO MAX6312UK35D1-T ABTE MAX6310UK40D4-T ABOJ MAX6310UK29D2-T ABPZ MAX6312UK46D4-T ABRP MAX6312UK35D2-T ABTF MAX6310UK39D1-T ABOK MAX6310UK29D3-T ABQA MAX6312UK45D1-T ABRQ MAX6312UK35D3-T ABTG MAX6310UK39D2-T ABOL MAX6310UK29D4-T ABQB MAX6312UK45D2-T ABRR MAX6312UK35D4-T ABTH MAX6310UK39D3-T ABOM MAX6310UK28D1-T ABQC MAX6312UK45D3-T ABRS MAX6312UK34D1-T ABTI MAX6310UK39D4-T ABON MAX6310UK28D2-T ABQD MAX6312UK45D4-T ABRT MAX6312UK34D2-T ABTJ MAX6310UK38D1-T ABOO MAX6310UK28D3-T ABQE MAX6312UK44D1-T ABRU MAX6312UK34D3-T ABTK MAX6310UK38D2-T ABOP MAX6310UK28D4-T ABQF MAX6312UK44D2-T ABRV MAX6312UK34D4-T ABTL MAX6310UK38D3-T ABOQ MAX6310UK27D1-T ABQG MAX6312UK44D3-T ABRW MAX6312UK33D1-T ABTM MAX6310UK38D4-T ABOR MAX6310UK27D2-T ABQH MAX6312UK44D4-T ABRX MAX6312UK33D2-T ABTN MAX6310UK37D1-T ABOS MAX6310UK27D3-T ABQI MAX6312UK43D1-T ABRY MAX6312UK33D3-T ABTO MAX6310UK37D2-T ABOT MAX6310UK27D4-T ABQJ MAX6312UK43D2-T ABRZ MAX6312UK33D4-T ABTP MAX6310UK37D3-T ABOU MAX6310UK26D1-T ABQK MAX6312UK43D3-T ABSA MAX6312UK32D1-T ABTQ MAX6310UK37D4-T ABOV MAX6310UK26D2-T ABQL MAX6312UK43D4-T ABSB MAX6312UK32D2-T ABTR MAX6310UK36D1-T ABOW MAX6310UK26D3-T ABQM MAX6312UK42D1-T ABSC MAX6312UK32D3-T ABTS MAX6310UK36D2-TABOXMAX6310UK26D4-TABQNMAX6312UK42D2-TABSDMAX6312UK32D4-TABTTDEVICECODE DEVICECODE DEVICECODE DEVICECODEM A X 6305–M A X 6313Programmable Reset ICs 12______________________________________________________________________________________Table 2. Device Marking Codes (continued)MAX6313UK49D2-T ABVB MAX6313UK49D3-T ABVC MAX6313UK49D4-T ABVD MAX6313UK48D1-T ABVE MAX6313UK48D2-T ABVF MAX6313UK48D3-T ABVG MAX6313UK48D4-T ABVH MAX6313UK47D1-T ABVI MAX6313UK47D2-T ABVJ MAX6313UK47D3-T ABVK MAX6313UK47D4-T ABVL MAX6313UK46D1-T ABVM MAX6313UK46D2-T ABVN MAX6313UK46D3-T ABVO MAX6313UK46D4-T ABVP MAX6313UK45D1-T ABVQ MAX6313UK45D2-T ABVR MAX6313UK45D3-T ABVS MAX6313UK45D4-T ABVT MAX6313UK44D1-T ABVU MAX6313UK44D2-T ABVV MAX6313UK44D3-T ABVW MAX6313UK44D4-T ABVX MAX6313UK43D1-T ABVY MAX6313UK43D2-T ABVZ MAX6313UK43D3-T ABWA MAX6313UK43D4-T ABWB MAX6313UK42D1-T ABWC MAX6313UK42D2-T ABWD MAX6313UK42D3-T ABWE MAX6313UK42D4-T ABWF MAX6313UK41D1-T ABWG MAX6313UK41D2-TABWHDEVICECODE DEVICECODE DEVICECODE DEVICECODE MAX6313UK33D4-T ABXP MAX6313UK32D1-T ABXQ MAX6313UK32D2-T ABXR MAX6313UK32D3-T ABXS MAX6313UK32D4-T ABXT MAX6313UK31D1-T ABXU MAX6313UK31D2-T ABXV MAX6313UK31D3-T ABXW MAX6313UK31D4-T ABXX MAX6313UK30D1-T ABXY MAX6313UK30D2-T ABXZ MAX6313UK30D3-T ABYA MAX6313UK30D4-T ABYB MAX6313UK29D1-T ABYC MAX6313UK29D2-T ABYD MAX6313UK29D3-T ABYE MAX6313UK29D4-T ABYF MAX6313UK28D1-T ABYG MAX6313UK28D2-T ABYH MAX6313UK28D3-T ABYI MAX6313UK28D4-T ABYJ MAX6313UK27D1-T ABYK MAX6313UK27D2-T ABYL MAX6313UK27D3-T ABYM MAX6313UK27D4-T ABYN MAX6313UK26D1-T ABYO MAX6313UK26D2-T ABYP MAX6313UK26D3-T ABYQ MAX6313UK26D4-T ABYR MAX6313UK25D1-T ABYS MAX6313UK25D2-T ABYT MAX6313UK25D3-T ABYU MAX6313UK25D4-TABYVMAX6313UK41D3-T ABWI MAX6313UK41D4-T ABWJ MAX6313UK40D1-T ABWK MAX6313UK40D2-T ABWL MAX6313UK40D3-T ABWM MAX6313UK40D4-T ABWN MAX6313UK39D1-T ABWO MAX6313UK39D2-T ABWP MAX6313UK39D3-T ABWQ MAX6313UK39D4-T ABWR MAX6313UK38D1-T ABWS MAX6313UK38D2-T ABWT MAX6313UK38D3-T ABWU MAX6313UK38D4-T ABWV MAX6313UK37D1-T ABWW MAX6313UK37D2-T ABWX MAX6313UK37D3-T ABWY MAX6313UK37D4-T ABWZ MAX6313UK36D1-T ABXA MAX6313UK36D2-T ABXB MAX6313UK36D3-T ABXC MAX6313UK36D4-T ABXD MAX6313UK35D1-T ABXE MAX6313UK35D2-T ABXF MAX6313UK35D3-T ABXG MAX6313UK35D4-T ABXH MAX6313UK34D1-T ABXI MAX6313UK34D2-T ABXJ MAX6313UK34D3-T ABXK MAX6313UK34D4-T ABXL MAX6313UK33D1-T ABXM MAX6313UK33D2-T ABXN MAX6313UK33D3-TABXOMAX6312UK31D1-T ABTU MAX6312UK31D2-T ABTV MAX6312UK31D3-T ABTW MAX6312UK31D4-T ABTX MAX6312UK30D1-T ABTY MAX6312UK30D2-T ABTZ MAX6312UK30D3-T ABUA MAX6312UK30D4-T ABUB MAX6312UK29D1-T ABUC MAX6312UK29D2-T ABUD MAX6312UK29D3-T ABUE MAX6312UK29D4-T ABUF MAX6312UK28D1-T ABUG MAX6312UK28D2-T ABUH MAX6312UK28D3-T ABUI MAX6312UK28D4-T ABUJ MAX6312UK27D1-T ABUK MAX6312UK27D2-T ABUL MAX6312UK27D3-T ABUM MAX6312UK27D4-T ABUN MAX6312UK26D1-T ABUO MAX6312UK26D2-T ABUP MAX6312UK26D3-T ABUQ MAX6312UK26D4-T ABUR MAX6312UK25D1-T ABUS MAX6312UK25D2-T ABUT MAX6312UK25D3-T ABUU MAX6312UK25D4-T ABUV MAX6313UK50D1-T ABUW MAX6313UK50D2-T ABUX MAX6313UK50D3-T ABUY MAX6313UK50D4-T ABUZ MAX6313UK49D1-TABVA。

MAX6387XS18D7中⽂资料General Description The MAX6381–MAX6390 microprocessor (µP) supervisory circuits monitor power-supply voltages from +1.8V to +5.0V while consuming only 3µA of supply current at +1.8V. Whenever V CC falls below the factory-set reset thresholds, the reset output asserts and remains assert-ed for a minimum reset timeout period after V CC rises above the reset threshold. Reset thresholds are available from +1.58V to +4.63V, in approximately 100mV incre-ments. Seven minimum reset timeout delays ranging from 1ms to 1200ms are available.The MAX6381/MAX6384/MAX6387 have a push-pull active-low reset output. The MAX6382/MAX6385/ MAX6388 have a push-pull active-high reset output, and the MAX6383/MAX6386/MAX6389/MAX6390 have an open-drain active-low reset output. The MAX6384/MAX6385/MAX6386 also feature a debounced manual reset input (with internal pullup resistor). The MAX6387/MAX6388/MAX6389 have an auxiliary input for monitoring a second voltage. The MAX6390 offers a manual reset input with a longer V CC reset timeout period (1120ms or 1200ms) and a shorter manual reset timeout (140ms or 150ms). The MAX6381/MAX6382/MAX6383 are available in 3-pin SC70 and6-pinµDFN packages and the MAX6384–MAX6390 are available in 4-pin SC70 andFeaturesFactory-Set Reset Threshold Voltages Rangingfrom +1.58V to +4.63V in Approximately 100mVIncrements±2.5% Reset Threshold Accuracy OverTemperature (-40°C to +125°C)Seven Reset Timeout Periods Available: 1ms,20ms, 140ms, 280ms, 560ms, 1120ms,1200ms (min)3 Reset Output OptionsActive-Low Push-PullActive-High Push-PullActive-Low Open-DrainReset Output State Guaranteed ValidDown to V CC= 1VManual Reset Input (MAX6384/MAX6385/MAX6386)Auxiliary RESET IN(MAX6387/MAX6388/MAX6389)V CC Reset Timeout (1120ms or 1200ms)/ManualReset Timeout (140ms or 150ms) (MAX6390)Negative-Going V CC Transient ImmunityLow Power Consumption of 6µA at +3.6Vand 3µA at +1.8VPin Compatible withMAX809/MAX810/MAX803/MAX6326/MAX6327/MAX6328/MAX6346/MAX6347/MAX6348,and MAX6711/MAX6712/MAX6713Tiny 3-Pin/4-Pin SC70 and 6-Pin µDFN PackagesMAX6381–MAX6390 SC70/µDFN, Single/Dual Low-Voltage,Low-Power µP Reset Circuits ________________________________________________________________Maxim Integrated Products1Pin Configurations19-1839; Rev 4; 4/07Ordering InformationOrdering Information continued at end of data sheet.Typi cal Operati ng Ci rcui t appears at end of data sheet.Selector Guide appears at end of data sheet.after "XR", "XS", or "LT." Insert reset timeout delay (see ResetTimeout Delay table) after "D" to complete the part number.Sample stock is generally held on standard versions only (seeStandard Versions table). Standard versions have an orderincrement requirement of 2500 pieces. Nonstandard versionshave an order increment requirement of 10,000 pieces.Contact factory for availability of nonstandard versions.+Denotes a lead-free package.For pricing, delivery, and ordering information,please contact Maxim Direct at 1-888-629-4642,or visit Maxim’s website at /doc/5700977901f69e3143329415.html .ComputersControllersIntelligent InstrumentsCritical µP and µCPower MonitoringPortable/Battery-Powered EquipmentDual Voltage SystemsM A X 6381–M A X 6390SC70/µDFN, Single/Dual Low-Voltage, Low-Power µP Reset CircuitsABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICS(V CC = full range, T A = -40°C to +125°C, unless otherwise specified. Typical values are at T A = +25°C.) (Note 1)Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.V CC to GND..........................................................-0.3V to +6.0V RESET Open-Drain Output....................................-0.3V to +6.0V RESET , RESET (push-pull output)..............-0.3V to (V CC + 0.3V)MR , RESET IN.............................................-0.3V to (V CC + 0.3V)Input Current (V CC ).............................................................20mA Output Current (all pins).....................................................20mAContinuous Power Dissipation (T A = +70°C)3-Pin SC70 (derate 2.9mW/°C above +70°C)..............235mW 4-Pin SC70 (derate 3.1mW/°C above +70°C)..............245mW 6-Pin µDFN (derate 2.1mW/°C above +70°C)..........167.7mW Operating Temperature Range .........................-40°C to+125°C Storage Temperature Range.............................-65°C to +150°C Lead Temperature (soldering,10s).................................+300°CMAX6381–MAX6390SC70/µDFN, Single/Dual Low-Voltage,Low-Power µP Reset Circuits_______________________________________________________________________________________3M A X 6381–M A X 6390SC70/µDFN, Single/Dual Low-Voltage, Low-Power µP Reset Circuits4______________________________________________________________________________________Typical Operating Characteristics(T A = +25°C, unless otherwise noted.)215436789-40-105-25203550658095110125SUPPLY CURRENT vs. TEMPERATURE(NO LOAD)TEMPERATURE (°C)S U P P L Y C U R R E N T (µA )25292735333137394143-40-105-25203550658095110125POWER-DOWN RESET DELAYvs. TEMPERATURETEMPERATURE (°C)P O W E R -D O W N R E S E T D E L A Y (µs )0.940.980.961.021.001.061.041.08-40-10520-253550658095110125 NORMALIZED POWER-UP RESET TIMEOUTvs. TEMPERATUREM A X 6381/90 t o c 03TEMPERATURE (°C)N O R M A L I Z E D R E S E T T I M E O U T P E R I O D0.9900.9851.0150.9950.9901.0001.0051.0101.020-40-10520-253550958011065125 M A X 6381/90 t o c 04TEMPERATURE (°C)N O R M A L I Z E D R E S E T TH R E S H O L D NORMALIZED RESET THRESHOLDvs. TEMPERATURE00.40.20.80.61.01.2063912OUTPUT-VOLTAGE LOW vs. SINK CURRENTI SINK (mA)V O L (V )01.00.52.01.52.53.00500750250100012501500OUTPUT-VOLTAGE HIGH vs. SOURCE CURRENTI SOURCE (µA)V O H (V )45001100010010MAXIMUM TRANSIENT DURATION vs. RESET COMPARATOR OVERDRIVE15050350250500200100400300RESET COMPARATOR OVERDRIVE, V TH - V CC (mV)M A X I M U M T R A N S I E N T D U R A T I O N (µs )3.53.93.74.54.34.14.74.95.35.15.5-40-105-25203550658095110125RESET IN TO RESET DELAYvs. TEMPERATUREM A X 6381/90 t o c 08TEMPERATURE (°C)R E S E T I N D E L A Y (µs )MAX6381–MAX6390SC70/µDFN, Single/Dual Low-Voltage,Low-Power µP Reset CircuitsPin DescriptionM A X 6381–M A X 6390SC70/µDFN, Single/Dual Low-Voltage, Low-Power µP Reset Circuits6_______________________________________________________________________________________ Detailed DescriptionRESET OutputA µP reset input starts the µP in a known state. These µP supervisory circuits assert reset to prevent code execution errors during power-up, power-down, or brownout conditions.Reset asserts when V CC is below the reset threshold;once V CC exceeds the reset threshold, an internal timer keeps the reset output asserted for the reset timeout period. After this interval, reset output deasserts. Reset output is guaranteed to bein the correct logic state for V CC ≥1V.Manual Reset Input (MAX6384/MAX6385/MAX6386/MAX6390)Many µP-based products require manual reset capabil-ity, allowing the operator, a test technician, or external logic circuitry to initiate a reset. A logic low on MR asserts reset. Reset remains asserted while MR is low,and for the reset active timeout period (t RP ) after MR returns high. This input has an internal 63k ?pullup resistor (1.56k ?for MAX6390), so it can be left uncon-nected if it is not used. MR can be driven with TTL or CMOS logic levels, or with open-drain/collector outputs.Connect a normally open momentary switch from MR to G ND to create a manual-reset function; external debounce circuitry is not required. If MR is driven from long cables or if the device is used in a noisy environ-ment, connecting a 0.1µF capacitor from MR to G ND provides additional noise immunity.RESET IN Comparator(MAX6387/MAX6388/MAX6389)RESET IN is compared to an internal +1.27V reference.If the voltage at RESET IN is less than 1.27V, reset asserts. Use the RESET IN comparator as a user-adjustable reset detector or as a secondary power-sup-ply monitor by implementing a resistor-divider at RESET IN (shown in Figure 1). Reset asserts when either V CC or RESET IN falls below its respective threshold volt-age. Use the following equation to set the threshold:V INTH = V THRST (R1/R2 + 1)where V THRST = +1.27V. To simplify the resistor selec-tion, choose a value of R2 and calculate R1:R1 = R2 [(V INTH /V THRST ) - 1]Since the input current at RESET IN is 50nA (max),large values can be used for R2 with no significant loss in accuracy.___________Applications InformationNegative-Going V CC TransientsIn addition to issuing a reset to the µP during power-up,power-down, and brownout conditions, the MAX6381–MAX6390 are relatively immune to short dura-tion negative-going V CC transients (glitches).The Typical Operating Characteristics section shows the Maximum Transient Durations vs. Reset Comparator Overdrive, for which the MAX6381–MAX6390 do not generate a reset pulse. This graph was generated usinga negative-going pulse applied to V CC , starting above the actual reset threshold and ending below it by the magnitude indicated (reset comparator overdrive). The graph indicates the typical maximum pulse width a neg-ative-going V CC transient may have without causing a reset pulse to be issued. As the magnitude of the tran-sient increases (goes farther below the reset threshold),the maximum allowable pulse width decreases. A 0.1µF capacitor mounted as close as possible to V CC provides additional transient immunity.Ensuring a Valid RESET Output Down to V CC = 0VThe MAX6381–MAX6390 are guaranteed to operate properly down to V CC = 1V. In applications that require valid reset levels down to V CC = 0V, a pulldown resistor to active-low outputs (push/pull only, Figure 2) and a pullup resistor to active-high outputs (push/pull only)will ensure that the reset line is valid while the reset out-put can no longer sink or source current. This schemedoes not work with the open-drain outputs of the MAX6383/MAX6386/MAX6389/MAX6390. The resistor value used is not critical, but it must be small enough not to load the reset output when V CC is above the reset threshold. For most applications, 100k ?is ade-quate.MAX6381–MAX6390SC70/µDFN, Single/Dual Low-Voltage,Low-Power µP Reset Circuits_______________________________________________________________________________________7M A X 6381–M A X 6390SC70/µDFN, Single/Dual Low-Voltage, Low-Power µP Reset Circuits 8_______________________________________________________________________________________ Selector GuideOrdering Information (continued)Note:Insert reset threshold suffix (see Reset Threshold table)after "XR", "XS", or "LT." Insert reset timeout delay (see Reset Timeout Delay table) after "D" to complete the part number.Sample stock is generally held on standard versions only (see Standard Versions table). Standard versions have an order increment requirement of 2500 pieces. Nonstandard versions have an order increment requirement of 10,000 pieces.Contact factory for availability of nonstandard versions.*MAX6390 is available with D4 or D7 timing only.+Denotes a lead-free package.MAX6381–MAX6390SC70/µDFN, Single/Dual Low-Voltage,Low-Power µP Reset Circuits_______________________________________________________________________________________9Chip InformationTRANSISTOR COUNT: 647PROCESS: BiCMOSPin Configurations (continued)M A X 6381–M A X 6390SC70/µDFN, Single/Dual Low-Voltage, Low-Power µP Reset Circuits10______________________________________________________________________________________ Package Information(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,go to /doc/5700977901f69e3143329415.html /packages .)MAX6381–MAX6390SC70/µDFN, Single/Dual Low-Voltage,Low-Power µP Reset Circuits______________________________________________________________________________________11Package Information (continued)(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,go to /doc/5700977901f69e3143329415.html /packages .)M A X 6381–M A X 6390SC70/µDFN, Single/Dual Low-Voltage, Low-Power µP Reset Circuits12______________________________________________________________________________________ Package Information (continued)(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,go to /doc/5700977901f69e3143329415.html /packages .)SC70/µDFN, Single/Dual Low-Voltage,Low-Power µP Reset CircuitsMaxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600____________________13?2007 Maxim Integrated Productsis a registered trademark of Maxim Integrated Products, Inc.MAX6381–MAX6390Package Information (continued)(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,go to /doc/5700977901f69e3143329415.html /packages .)Revision HistoryPages changed at Rev 4: Title on all pages, 1, 2, 5,7–13。

General DescriptionThe MX536A and MX636 are true RMS-to-DC convert-ers. They feature low power and are designed to accept low-level input signals from 0 to 7V RMS for the MX536A and 0 to 200mV RMS for the MX636. Both devices accept complex input waveforms containing AC and DC com-ponents. They can be operated from either a single sup-ply or dual supplies. Both devices draw less than 1mA of quiescent supply current, making them ideal for bat-tery-powered applications.Input and output offset, positive and negative waveform symmetry (DC reversal), and full-scale accuracy are laser trimmed, so that no external trims are required to achieve full rated accuracy.________________________ApplicationsDigital MultimetersBattery-Powered Instruments Panel Meters Process Control____________________________Featureso True RMS-to-DC Conversiono Computes RMS of AC and DC Signals o Wide Response:2MHz Bandwidth for V RMS > 1V (MX536A)1MHz Bandwidth for V RMS > 100mV (MX636)o Auxiliary dB Output:60dB Range (MX536A)50dB Range (MX636)o Single- or Dual-Supply Operation o Low Power: 1.2mA typ (MX536A)800µA typ (MX636)MX536A/MX636True RMS-to-DC Converters________________________________________________________________Maxim Integrated Products1Pin Configurations_________Typical Operating Circuits19-0824; Rev 2; 3/96Ordering Information continued at end of data sheet.*Maxim reserves the right to ship ceramic packages in lieu of CERDIP packages.** Dice are specified at T A = +25°C.For free samples & the latest literature: , or phone 1-800-998-8800.For small orders, phone 408-737-7600 ext. 3468.M X 536A /M X 636True RMS-to-DC Converters 2_______________________________________________________________________________________ABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICS—MX536A(T A = +25°C, +V S = +15V, -V S = -15V, unless otherwise noted.)Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.Supply Voltage:Dual Supplies (MX536A)............................±18V(MX636).............................±12VSingle Supply (MX536A)...........................+36V(MX636).............................+24VInput Voltage (MX536A).......................................................±25V(MX636).........................................................±12VPower Dissipation (Package)Plastic DIP (derate 12mW/°C above +75°C)...............450mW Small Outline (derate 10mW/°C above +75°C)............400mW Ceramic (derate 10mW/°C above +75°C)...................500mW TO-100 metal can (derate 7mW/°C above +75°C)......450mWOutput Short-Circuit Duration........................................Indefinite Operating Temperature RangesCommercial (J, K)...............................................0°C to +70°C Military (S)......................................................-55°C to +125°C Storage Temperature Range.............................-55°C to +150°C Lead Temperature (soldering, 10sec)................................300°CMX536A/MX636True RMS-to-DC Converters_______________________________________________________________________________________3ELECTRICAL CHARACTERISTICS—MX536A (continued)(T A = +25°C, +V S = +15V, -V S = -15V, unless otherwise noted.)M X 536A /M X 636True RMS-to-DC Converters 4_______________________________________________________________________________________ELECTRICAL CHARACTERISTICS—MX536A (continued)(T A = +25°C, +V S = +15V, -V S = -15V, unless otherwise noted.)ELECTRICAL CHARACTERISTICS—MX636(T A = +25°C, +V S = +3V, -V S = -5V, unless otherwise noted.)MX536A/MX636True RMS-to-DC Converters_______________________________________________________________________________________5ELECTRICAL CHARACTERISTICS—MX636 (continued)(T= +25°C, +V = +3V, -V = -5V, unless otherwise noted.)M X 536A /M X 636_______________Detailed DescriptionThe MX536A/MX636 uses an implicit method of RMS computation that overcomes the dynamic range as well as other limitations inherent in a straightforward compu-tation of the RMS. The actual computation performed by the MX536A/MX636 follows the equation:V RMS = Avg. [V IN 2/V RMS ]The input voltage, V IN , applied to the MX536A/MX636 is processed by an absolute-value/voltage to current con-verter that produces a unipolar current I 1(Figure 1).This current drives one input of a squarer/divider that produces a current I 4that has a transfer function:I 4= I 12I 3The current I 4drives the internal current mirror through a lowpass filter formed by R1 and an external capaci-tor, C AV . As long as the time constant of this filter is greater than the longest period of the input signal, I 4is averaged. The current mirror returns a current, I 3, to the square/divider to complete the circuit. The current I 4is then a function of the average of (I 12/I 4), which is equal to I 1RMS .The current mirror also produces a 2 · I 4output current,I OUT , that can be used directly or converted to a volt-age using resistor R2 and the internal buffer to provide a low-impedance voltage output. The transfer function for the MX536A/MX636 is:V OUT = 2 · R2 · I RMS = V INThe dB output is obtained by the voltage at the emitter of Q3, which is proportional to the -log V IN . The emitter follower Q5 buffers and level shifts this voltage so that the dB output is zero when the externally set emitter current for Q5 approximates I 3.Standard Connection(Figure 2)The standard RMS connection requires only one exter-nal component, C AV . In this configuration the MX536A/MX636 measures the RMS of the AC and DC levels present at the input, but shows an error for low-frequency inputs as a function of the C AV filter capaci-tor. Figure 3 gives practical values of C AV for various values of averaging error over frequency for the stan-dard RMS connections (no post filtering). If a 3µF capacitor is chosen, the additional error at 100Hz will be 1%. If the DC error can be rejected, a capacitor should be connected in series with the input, as would typically be the case in single-supply operation.The input and output signal ranges are a function of the supply voltages. Refer to the electrical characteristics for guaranteed performance. The buffer amplifier can be used either for lowering the output impedance of the cir-cuit, or for other applications such as buffering high-impedance input signals. The MX536A/MX636 can be used in current output mode by disconnecting the inter-nal load resistor, R L , from ground. The current output is available at pin 8 (pin 10 on the “H” package) with a nominal scale of 40µA/V RMS input for the MX536A and 100µA/V RMS input for the MX636. The output is positive.True RMS-to-DC Converters 6_______________________________________________________________________________________ELECTRICAL CHARACTERISTICS—MX636 (continued)(T= +25°C, +V = +3V, -V = -5V, unless otherwise noted.)Note 1:Accuracy is specified for 0 to 7V RMS , DC or 1kHz sine-wave input with the MX536A connected as in Figure 2.Note 2:Error vs. crest factor is specified as an additional error for 1V RMS rectangular pulse stream, pulse width = 200µs.Note 3:Input voltages are expressed in volts RMS, and error as % of reading.Note 4:With 2k Ωexternal pull-down resistor.Note 5:Accuracy is specified for 0 to 200mV, DC or 1kHz sine-wave input. Accuracy is degraded at higher RMS signal levels.Note 6:Measured at pin 8 of DIP and SO (I OUT ), with pin 9 tied to COMMON.Note 7:Error vs. crest factor is specified as an additional error for 200mV RMS rectangular pulse input, pulse width = 200µs.Note 8:Input voltages are expressed in volts RMS.Note 9:With 10k Ωexternal pull-down resistor from pin 6 (BUF OUT) to -V S .Note 10:With BUF input tied to COMMON.MX536A/MX636True RMS-to-DC Converters_______________________________________________________________________________________7Figure 1. MX536A Simplified SchematicFigure 2. MX536A/MX636 Standard RMS ConnectionM X 536A /M X 636High-Accuracy AdjustmentsThe accuracy of the MX536A/MX636 can be improved by the addition of external trims as shown in Figure 4.R4 trims the offset. The input should be grounded and R4 adjusted to give zero volts output from pin 6. R1 is trimmed to give the correct value for either a calibrated DC input or a calibrated AC signal. For example: 200mV DC input should give 200mV DC output; a ±200mV peak-to-peak sine-wave should give 141mV DC output.Single-Supply OperationBoth the MX536A and the MX636 can be used with a single supply down to +5V (Figure 5). The major limita-tion of this connection is that only AC signals can be measured, since the differential input stage must be biased off ground for proper operation. The load resis-tor is necessary to provide output sink current. The input signal is coupled through C2 and the value cho-sen so that the desired low-frequency break point is obtained with the input resistance of 16.7k Ωfor the MX536A and 6.7k Ωfor the MX636.Figure 5 shows how to bias pin 10 within the range of the supply voltage (pin 2 on “H” packages). It is critical that no extraneous signals are coupled into this pin. A capacitor connected between pin 10 and ground is recommended. The common pin requires less than 5µA of input current, and if the current flowing through resis-tors R1 and R2 is chosen to be approximately 10 times the common pin current, or 50µA, the resistor values can easily be calculated.Choosing the Averaging Time ConstantBoth the MX536A and MX636 compute the RMS value of AC and DC signals. At low frequencies and DC, the output tracks the input exactly; at higher frequencies,the average output approaches the RMS value of the input signal. The actual output differs from the ideal by an average (or DC) error plus some amount of ripple.The DC error term is a function of the value of C AV and the input signal frequency. The output ripple is inverse-True RMS-to-DC Converters 8_______________________________________________________________________________________Figure 3. Lower Frequency for Stated % of Reading Error and Settling Time for Circuit shown in Figure 2Figure 4. Optional External Gain and Output Offset TrimsFigure 5. Single-Supply Operationly proportional to the value of C AV . Waveforms with high crest factors, such as a pulse train with low duty cycle,should have an average time constant chosen to be at least ten times the signal period.Using a large value of C AV to remove the output ripple increases the settling time for a step change in the input signal level. Figure 3 shows the relationship between C AV and settling time, where 115ms settling equals 1µF of C AV . The settling time, or time for the RMS converter to settle to within a given percent of the change in RMS level, is set by the averaging time constant, which varies approximately 2:1 between increasing and decreasing input signals. For example, increasing input signals require 2.3 time constants to settle to within 1%, and 4.6time constants for decreasing signals levels.In addition, the settling time also varies with input signal levels, increasing as the input signal is reduced, and decreasing as the input is increased as shown in Figures 6a and 6b.Using Post FiltersA post filter allows a smaller value of C AV , and reduces ripple and improves the overall settling time. The value of C AV should be just large enough to give the maxi-mum DC error at the lowest frequency of interest. The post filter is used to remove excess output ripple.Figures 7, 8, and 9 give recommended filter connec-tions and values for both the MX536A and MX636.Table 1 lists the number of time constants required for the RMS section to settle to within different percentages of the final value for a step change in the input signal.Decibel Output (dB)The dB output of the MX536A/MX636 originates in the squarer/divider section and works well over a 60dB range. The connection for dB measurements is shown in Figure 10. The dB output has a temperature drift of 0.03dB/°C, and in some applications may need to be compensated. Figure 10 shows a compensation scheme. The amplifier can be used to scale the output for a particular application. The values used in Figure 10 give an output of +100mV/dB.MX536A/MX636True RMS-to-DC Converters_______________________________________________________________________________________910012.51m100m10157.5RMS INPUT LEVEL (V)S E T T L I N G T I M E R E L A T I V E T O 1V R M S I N P U T S E T T L I N G T I M E10mMX536AFigure 6a. MX536A Settling Time vs. Input Level 10012.51m100m157.5RMS INPUT LEVEL (V)S E T T L I N G T I M E R E L A T I V E T O 200m V R M S I N P U T S E T T L I N G T I M E10mMX636Figure 6b. MX636 Settling Time vs. Input LevelNote:(τ) Settling Times for Linear RC FilterM X 536A /M X 636Frequency ResponseThe MX536A/MX636 utilizes a logarithmic circuit in per-forming the RMS computation of the input signal. The bandwidth of the RMS converters is proportional to sig-nal level. Figures 11 and 12 represent the frequency response of the converters from 10mV to 7V RMS for the MX536A and 1mV to 1V for the MX636, respectively.The dashed lines indicate the upper frequency limits for 1%, 10%, and ±3dB of reading additional error.Caution must be used when designing RMS measuring systems so that overload does not occur. The input clipping level for the MX636 is ±12V, and for the MX536A it is ±20V. A 7V RMS signal with a crest factor of 3 has a peak input of 21V.Application in a Low-Cost DVMA low-cost digital voltmeter (DVM) using just two inte-grated circuits plus supporting circuitry and LCD dis-play is shown in Figure 13. The MAX130 is a 3 1/2 digit integrating A/D converter with precision bandgap refer-ence. The 10M Ωinput attenuator is AC coupled to pin 6 of the MX636 buffer amplifier. The output from the MX636 is connected to the MAX130 to give a direct reading to the LCD display.True RMS-to-DC Converters 10______________________________________________________________________________________Figure 7. MX536A/MX636 with a One-Pole Output FilterFigure 8. MX536A/MX636 with a Two-Pole Output FilterFigure 9. Performance Features of Various Filter Types for MX536A/MX636MX536A/MX636True RMS-to-DC Converters______________________________________________________________________________________11Figure 10. dB ConnectionFigure 12. MX636 High-Frequency ResponseFigure 11. MX536A High-Frequency Response*** Dice are specified at T A = +25°C.M X 536A /M X 636True RMS-to-DC Converters Pin Configurations (continued)Figure 13. Portable High-Z Input RMS DPM and dB MeterTypical Operating________________Circuits (continued)___________________________________________Ordering Information (continued)Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.12____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600©1998 Maxim Integrated ProductsPrinted USAis a registered trademark of Maxim Integrated Products.。

____________________________________概述MAX6950/MAX6951是紧凑的共阴极显示驱动器，通过SPI TM 、QSPI TM 、MICROWIRE TM 兼容的串行接口，连接微处理器和独立的7段LED数码管、条形图或分立的LED。

电源电压可低至2.7V。

MAX6950可驱动5位7段数码管或40个分立的LED。

MAX6951可驱动8位7段数码管或64个分立的LED。

内置16进制字符译码器(0–9，A –F)、复用扫描电路、段码和位驱动器，以及存储每一位数据的静态RAM。

用户可以为每一个显示位选择16进制译码方式，或非译码方式，驱动任何7段码组合、柱状图或分立LED。

LED段电流由内部数字亮度控制电路设定，段驱动器为限斜率输出，以降低EMI。

每个显示位单独寻址和刷新，无须重写所有显示单元。

这些器件具有低功耗关断模式、数字亮度控制电路、扫描限制寄存器(允许用户选择1至8位显示)、各驱动器可相互保持同步的段闪烁控制，以及强制所有LED点亮的测试模式。

____________________________________应用机顶盒面板仪表白色家电条形图和点阵显示器工业控制器和仪表专业音响设备医疗设备____________________________________特性♦兼容于高速、26MHz、SPI/QSPI/MICROWIRE 串行接口♦工作电压+2.7V至+5.5V ♦独立的LED段控制♦各驱动器可相互保持同步的段闪烁控制♦16进制译码/非译码位选择♦数字亮度控制♦上电时所有显示器关闭♦驱动共阴极LED数码管♦复用时钟可同步于外部时钟♦限斜率的段驱动器，以降低EMI ♦75µA低功耗关断模式(数据保持不变)♦小巧的16引脚QSOP封装MAX6950/MAX6951串行接口、+2.7V至+5.5V、5位和8位LED显示驱动器________________________________________________________________Maxim Integrated Products 1________________________________引脚配置________________________________定购信息功能图参见产品资料的末尾部分。

General DescriptionMaxim’s MAX630 and MAX4193 CMOS DC-DC regula-tors are designed for simple, efficient, minimum-size DC-DC converter circuits in the 5mW to 5W range. The MAX630 and MAX4193 provide all control and power handling functions in a compact 8-pin package: a 1.31V bandgap reference, an oscillator, a voltage com-parator, and a 375mA N-channel output MOSF ET. A comparator is also provided for low-battery detection.Operating current is only 70µA and is nearly indepen-dent of output switch current or duty cycle. A logic-level input shuts down the regulator to less than 1µA quies-cent current. Low-current operation ensures high effi-ciency even in low-power battery-operated systems.The MAX630 and MAX4193 are compatible with most battery voltages, operating from 2.0V to 16.5V.The devices are pin compatible with the Raytheon bipo-lar circuits, RC4191/2/3, while providing significantly improved efficiency and low-voltage operation. Maxim also manufactures the MAX631, MAX632, and MAX633DC-DC converters, which reduce the external compo-nent count in fixed-output 5V, 12V, and 15V circuits.See Table 2 at the end of this data sheet for a summary of other Maxim DC-DC converters.Applications+5V to +15V DC-DC ConvertersHigh-Efficiency Battery-Powered DC-DC Converters+3V to +5V DC-DC Converters 9V Battery Life ExtensionUninterruptible 5V Power Supplies5mW to 5W Switch-Mode Power SuppliesFeatures♦High Efficiency—85% (typ)♦70µA Typical Operating Current ♦1µA Maximum Quiescent Current ♦2.0V to 16.5V Operation♦525mA (Peak) Onboard Drive Capability ♦±1.5% Output Voltage Accuracy (MAX630)♦Low-Battery Detector♦Compact 8-Pin Mini-DIP and SO Packages ♦Pin Compatible with RC4191/2/3MAX630/MAX4193CMOS Micropower Step-UpSwitching Regulator________________________________________________________________Maxim Integrated Products 1Pin ConfigurationOrdering InformationTypical Operating Circuit19-0915; Rev 2; 9/08For pricing, delivery, and ordering information,please contact Maxim/Dallas Direct!at 1-888-629-4642, or visit Maxim’s website at .*Dice are specified at T A = +25°C. Contact factory for dice specifications.**Contact factory for availability and processing to MIL-STD-883.†Contact factory for availibility.M A X 630/M A X 4193CMOS Micropower Step-Up Switching Regulator 2_______________________________________________________________________________________ABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICSStresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.Supply Voltage.......................................................................18V Storage Temperature Range ............................-65°C to +160°C Lead Temperature (soldering, 10s).................................+300°C Operating Temperature RangeMAX630C, MAX4193C........................................0°C to +70°C MAX630E, MAX4193E.....................................-40°C to +85°C MAX630M, MAX4193M..................................-55°C to +125°CPower Dissipation8-Pin PDIP (derate 6.25mW/°C above +50°C).............468mW 8-Pin SO (derate 5.88mW/°C above +50°C)................441mW 8-Pin CERDIP (derate 8.33mW/°C above +50°C)........833mW Input Voltage (Pins 1, 2, 6, 7).....................-0.3V to (+V S + 0.3V)Output Voltage, L X and LBD..................................................18V L X Output Current..................................................525mA (Peak)LBD Output Current............................................................50mAMAX630/MAX4193CMOS Micropower Step-UpSwitching Regulator_______________________________________________________________________________________3L X ON-RESISTANCE vs.TEMPERATURETEMPERATURE (°C)L X R O N (Ω)100755025-25-5024680125SUPPLY CURRENT vs.TEMPERATUREM A X 630/4193 t o c 02TEMPERATURE (°C)I S (μA )100755025-25-50402080601201001400125SUPPLY CURRENT vs.SUPPLY VOLTAGEM A X 630/4193 t o c 03+V S (V)I S (μA )14121086425015010025020030016Typical Operating Characteristics(T A = +25°C, unless otherwise noted.)ELECTRICAL CHARACTERISTICSNote 1:Guaranteed by correlation with DC pulse measurements.Note 2:The operating frequency range is guaranteed by design and verified with sample testing.Detailed DescriptionThe operation of the MAX630 can best be understood by examining the voltage regulating loop of F igure 1.R1 and R2 divide the output voltage, which is com-pared with the 1.3V internal reference by comparator COMP1. When the output voltage is lower than desired,the comparator output goes high and the oscillator out-put pulses are passed through the NOR gate latch,turning on the output N-channel MOSFET at pin 3, L X .As long as the output voltage is less than the desired voltage, pin 3 drives the inductor with a series of pulses at the oscillator frequency.Each time the output N-channel MOSFET is turned on,the current through the external coil, L1, increases,storing energy in the coil. Each time the output turns off,the voltage across the coil reverses sign and the volt-age at L X rises until the catch diode, D1, is forward biased, delivering power to the output.When the output voltage reaches the desired level,1.31V x (1 + R1 / R2), the comparator output goes low and the inductor is no longer pulsed. Current is then supplied by the filter capacitor, C1, until the output volt-age drops below the threshold, and once again L X is switched on, repeating the cycle. The average duty cycle at L X is directly proportional to the output current.Output Driver (L X Pin)The MAX630/MAX4193 output device is a large N-channel MOSFET with an on-resistance of 4Ωand a peak current rating of 525mA. One well-known advan-tage that MOSF ETs have over bipolar transistors in switching applications is higher speed, which reduces switching losses and allows the use of smaller, lighter,less costly magnetic components. Also important is that MOSF ETs, unlike bipolar transistors, do not require base current that, in low-power DC-DC converters,often accounts for a major portion of input power.The operating current of the MAX630 and MAX4193increases by approximately 1µA/kHz at maximum power output due to the charging current required by the gate capacitance of the L X output driver (e.g., 40µA increase at a 40kHz operating frequency). In compari-son, equivalent bipolar circuits typically drive their NPN L X output device with 2mA of base drive, causing the bipolar circuit’s operating current to increase by a fac-tor of 10 between no load and full load.OscillatorThe oscillator frequency is set by a single external, low-cost ceramic capacitor connected to pin 2, C X . 47pF sets the oscillator to 40kHz, a reasonable compromise between lower switching losses at low frequencies and reduced inductor size at higher frequencies.M A X 630/M A X 4193CMOS Micropower Step-Up Switching Regulator 4_______________________________________________________________________________________Low-Battery DetectorThe low-battery detector compares the voltage on LBR with the internal 1.31V reference. The output, LBD, is an open-drain N-channel MOSFET. In addition to detecting and warning of a low battery voltage, the comparator can also perform other voltage-monitoring operations such as power-failure detection.Another use of the low-battery detector is to lower the oscillator frequency when the input voltage goes below a specified level. Lowering the oscillator frequency increases the available output power, compensating for the decrease in available power caused by reduced input voltage (see Figure 5).Logic-Level Shutdown InputThe shutdown mode is entered whenever I C (pin 6) is driven below 0.2V or left floating. When shut down, theMAX630’s analog circuitry, oscillator, L X , and LBD out-puts are turned off. The device’s quiescent current dur-ing shutdown is typically 10nA (1µA max).Bootstrapped OperationIn most circuits, the preferred source of +V S voltage for the MAX630 and MAX4193 is the boosted output volt-age. This is often referred to as a “bootstrapped” oper-ation since the circuit figuratively “lifts” itself up.The on-resistance of the N-channel L X output decreas-es with an increase in +V S ; however, the device operat-ing current goes up with +V S (see the Typical Operating Characteristics , I S vs. +V S graph). In circuits with very low output current and input voltages greater than 3V, it may be more efficient to connect +V S direct-ly to the input voltage rather than bootstrap.MAX630/MAX4193CMOS Micropower Step-UpSwitching Regulator_______________________________________________________________________________________5Figure 1. +5V to +15V Converter and Block DiagramM A X 630/M A X 4193External ComponentsResistorsSince the LBR and V FB input bias currents are specified as 10nA (max), the current in the dividers R1/R2 and R3/R4 (Figure 1) may be as low as 1µA without signifi-cantly affecting accuracy. Normally R2 and R4 are between 10k Ωand 1M Ω, which sets the current in the voltage-dividers in the 1.3µA to 130µA range. R1 and R3 can then be calculated as follows:where V OUT is the desired output voltage and V LB isthe desired low-battery warning threshold.If the I C (shutdown) input is pulled up through a resistor rather than connected directly to +V S , the current through the pullup resistor should be a minimum of 4µAInductor ValueThe available output current from a DC-DC voltageboost converter is a function of the input voltage, exter-nal inductor value, output voltage, and the operating frequency.The inductor must 1) have the correct inductance, 2) be able to handle the required peak currents, and 3) have acceptable series resistance and core losses. If the inductance is too high, the MAX630 will not be able to deliver the desired output power, even with the L X out-put on for every oscillator cycle. The available output power can be increased by either decreasing the inductance or the frequency. Reducing the frequency increases the on-period of the L X output, thereby increasing the peak inductor current. The available out-put power is increased since it is proportional to the square of the peak inductor current (I PK ).where P OUT includes the power dissipated in the catchdiode (D1) as well as that in the load. If the inductance is too low, the current at L X may exceed the maximum rating. The minimum allowed inductor value is expressed by:where I MAX ≈525mA (peak L X current) and t ON is the on-time of the L X output.The most common MAX630 circuit is a boost-mode converter (Figure 1). When the N-channel output device is on, the current linearly rises since:At the end of the on-time (14µs for 40kHz, 55% duty-cycle oscillator) the current is:The energy in the coil is:At maximum load, this cycle is repeated 40,000 timesper second, and the power transferred through the coil is 40,000 x 5.25 = 210mW. Since the coil only supplies the voltage above the input voltage, at 15V, the DC-DC converter can supply 210mW / (15V - 5V) = 21mA. The coil provides 210mW and the battery directly supplies another 105mW, for a total of 315mW of output power. If the load draws less than 21mA, the MAX630 turns on its output only often enough to keep the output voltage at a constant 15V.Reducing the inductor value increases the available output current: lower L increases the peak current,thereby increasing the available power. The external inductor required by the MAX630 is readily obtained from a variety of suppliers (Table 1). Standard coils are suitable for most applications.Types of InductorsMolded InductorsThese are cylindrically wound coils that look similar to 1W resistors. They have the advantages of low cost and ease of handling, but have higher resistance, higher losses, and lower power handling capability than other types.102112131131104134131131ΩΩΩΩ≤≤=−≤≤=− .. ..R M R R x V VR M R R x V VOUTLBCMOS Micropower Step-Up Switching Regulator 6_______________________________________________________________________________________Potted Toroidal InductorsA typical 1mH, 0.82Ωpotted toroidal inductor (Dale TE-3Q4TA) is 0.685in in diameter by 0.385in high and mounts directly onto a PC board by its leads. Such devices offer high efficiency and mounting ease, but at a somewhat higher cost than molded inductors.Ferrite Cores (Pot Cores)Pot cores are very popular as switch-mode inductors since they offer high performance and ease of design.The coils are generally wound on a plastic bobbin,which is then placed between two pot core sections. A simple clip to hold the core sections together com-pletes the inductor. Smaller pot cores mount directly onto PC boards through the bobbin terminals. Cores come in a wide variety of sizes, often with the center posts ground down to provide an air gap. The gap pre-vents saturation while accurately defining the induc-tance per turn squared.Pot cores are suitable for all DC-DC converters, but are usually used in the higher power applications. They are also useful for experimentation since it is easy to wind coils onto the plastic bobbins.Toroidal CoresIn volume production, the toroidal core offers high per-formance, low size and weight, and low cost. They are,however, slightly more difficult for prototyping, in that manually winding turns onto a toroid is more tedious than on the plastic bobbins used with pot cores.Toroids are more efficient for a given size since the flux is more evenly distributed than in a pot core, where the effective core area differs between the post, side, top,and bottom.Since it is difficult to gap a toroid, manufacturers produce toroids using a mixture of ferromagnetic powder (typically iron or Mo-Permalloy powder) and a binder. The perme-ability is controlled by varying the amount of binder,which changes the effective gap between the ferromag-netic particles. Mo-Permalloy powder (MPP) cores have lower losses and are recommended for the highest effi-ciency, while iron powder cores are lower cost.DiodesIn most MAX630 circuits, the inductor current returns to zero before L X turns on for the next output pulse. This allows the use of slow turn-off diodes. On the other hand, the diode current abruptly goes from zero to full peak current each time L X switches off (Figure 1, D1).To avoid excessive losses, the diode must therefore have a fast turn-on time.F or low-power circuits with peak currents less than 100mA, signal diodes such as 1N4148s perform well.For higher-current circuits, or for maximum efficiency at low power, the 1N5817 series of Schottky diodes are recommended. Although 1N4001s and other general-purpose rectifiers are rated for high currents, they are unacceptable because their slow turn-on time results in excessive losses.MAX630/MAX4193CMOS Micropower Step-UpSwitching Regulator_______________________________________________________________________________________7Table 1. Coil and Core ManufacturersM A X 630/M A X 4193Filter CapacitorThe output-voltage ripple has two components, with approximately 90 degrees phase difference between them. One component is created by the change in the capacitor’s stored charge with each output pulse. The other ripple component is the product of the capacitor’s charge/discharge current and its effective series resis-tance (ESR). With low-cost aluminum electrolytic capacitors, the ESR-produced ripple is generally larger than that caused by the change in charge.where V IN is the coil input voltage, L is its inductance, f is the oscillator frequency, and ESR is the equivalent series resistance of the filter capacitor.The output ripple resulting from the change in charge on the filter capacitor is:where t CHG and t DIS are the charge and dischargetimes for the inductor (1/2f can be used for nominal cal-culations).Oscillator Capacitor, C XThe oscillator capacitor, C X , is a noncritical ceramic or silver mica capacitor. C X can also be calculated by:where f is the desired operating frequency in Hertz, and C INT is the sum of the stray capacitance on the C X pin and the internal capacitance of the package. The internal capacitance is typically 1pF for the plastic package and 3pF for the CERDIP package. Typical stray capacitances are about 3pF for normal PC board layouts, but will be significantly higher if a socket is used.Bypassing and CompensationSince the inductor-charging current can be relatively large, high currents can flow through the ground con-nection of the MAX630/MAX4193. To prevent unwanted feedback, the impedance of the ground path must be as low as possible, and supply bypassing should be used for the device.When large values (>50k Ω) are used for the voltage-setting resistors, R1 and R2 of F igure 1, stray capaci-tance at the V FB input can add a lag to the feedback response, destabilizing the regulator, increasing low-frequency ripple, and lowering efficiency. This can often be avoided by minimizing the stray capacitance at the V FB node. It can also be remedied by adding a lead compensation capacitor of 100pF to 10nF in paral-lel with R1 in Figure 1.DC-DC Converter ConfigurationsDC-DC converters come in three basic topologies:buck, boost, and buck-boost (Figure 2). The MAX630 is usually operated in the positive-voltage boost circuit,where the output voltage is greater than the input.The boost circuit is used where the input voltage is always less than the desired output and the buck circuit is used where the input is greater than the output. Thebuck-boost circuit inverts, and can be used with, inputCMOS Micropower Step-Up Switching Regulator 8_______________________________________________________________________________________Figure 2. DC-DC Converter Configurationsvoltages that are either greater or less than the output. DC-DC converters can also be classified by the control method. The two most common are pulse-width modu-lation (PWM) and pulse-frequency modulation (PF M). PWM switch-mode power-supply ICs (of which current-mode control is one variant) are well-established in high-power off-line switchers. Both PWM and PF M cir-cuits control the output voltage by varying duty cycle. In the PWM circuit, the frequency is held constant and the width of each pulse is varied. In the PFM circuit, the pulse width is held constant and duty cycle is con-trolled by changing the pulse repetition rate.The MAX630 refines the basic PFM by employing a con-stant-frequency oscillator. Its output MOSFET is switched on when the oscillator is high and the output voltages is lower than desired. If the output voltage is higher than desired, the MOSFET output is disabled for that oscillator cycle. This pulse skipping varies the average duty cycle, and thereby controls the output voltage.Note that, unlike the PWM ICs, which use an op amp as the control element, the MAX630 uses a comparator tocompare the output voltage to an onboard reference. This reduces the number of external components and operating current.Typical Applications+5V to +15V DC-DC Converter Figure 1 shows a simple circuit that generates +15V at approximately 20mA from a +5V input. The MAX630 has a ±1.5% reference accuracy, so the output voltage has an untrimmed accuracy of ±3.5% if R1 and R2 are 1% resistors. Other output voltages can also be select-ed by changing the feedback resistors. Capacitor C X sets the oscillator frequency (47pF = 40kHz), while C1 limits output ripple to about 50mV.With a low-cost molded inductor, the circuit’s efficiency is about 75%, but an inductor with lower series resis-tance such as the Dale TE3Q4TA increases efficiency to around 85%. A key to high efficiency is that the MAX630 itself is powered from the +15V output. This provides the onboard N-channel output device with 15V gate drive, lowering its on-resistance to about 4Ω. When +5V power is first applied, current flows through L1 and D1, supplying the MAX630 with 4.4V for startup.+5V to ±15V DC-DC Converter The circuit in F igure 3 is similar to that of F igure 1 except that two more windings are added to the induc-tor. The 1408 (14mm x 8mm) pot core specified is an IEC standard size available from many manufacturers (see Table 1). The -15V output is semiregulated, typi-cally varying from -13.6V to -14.4V as the +15V load current changes from no load to 20mA.2.5W, 3V to 5V DC-DC ConverterSome systems, although battery powered, need high currents for short periods, and then shut down to a low-power state. The extra circuitry of Figure 4 is designed tomeet these high-current needs. Operating in the buck-boost or flyback mode, the circuit converts -3V to +5V.The left side of Figure 4 is similar to Figure 1 and sup-plies 15V for the gate drive of the external power MOS-FET. This 15V gate drive ensures that the external deviceis completely turned on and has low on-resistance.The right side of F igure 4 is a -3V to +5V buck-boost converter. This circuit has the advantage that when theMAX630 is turned off, the output voltage falls to 0V,unlike the standard boost circuit, where the output volt-age is V BATT- 0.6V when the converter is shut down.When shut down, this circuit uses less than 10µA, withmost of the current being the leakage current of the power MOSFET.The inductor and output-filter capacitor values havebeen selected to accommodate the increased power levels. With the values indicated, this circuit can supplyup to 500mA at 5V, with 85% efficiency. Since the leftside of the circuit powers only the right-hand MAX630,the circuit starts up with battery voltages as low as1.5V, independent of the loading on the +5V output.MAX630/MAX4193CMOS Micropower Step-UpSwitching Regulator _______________________________________________________________________________________9M A X 630/M A X 4193+3V Battery to +5V DC-DC ConverterA common power-supply requirement involves conver-sion of a 2.4V or 3V battery voltage to a 5V logic sup-ply. The circuit in Figure 5 converts 3V to 5V at 40mA with 85% efficiency. When I C (pin 6) is driven low, the output voltage will be the battery voltage minus the drop across diode D1.The optional circuitry using C1, R3, and R4 lowers the oscillator frequency when the battery voltage falls to 2.0V. This lower frequency maintains the output-power capability of the circuit by increasing the peak inductor current, compensating for the reduced battery voltage.Uninterruptable +5V SupplyIn Figure 6, the MAX630 provides a continuous supply of regulated +5V, with automatic switchover between line power and battery backup. When the line-powered input voltage is at +5V, it provides 4.4V to the MAX630and trickle charges the battery. If the line-powered input falls below the battery voltage, the 3.6V battery supplies power to the MAX630, which boosts the bat-tery voltage up to +5V, thus maintaining a continuous supply to the uninterruptable +5V bus. Since the +5V output is always supplied through the MAX630, there are no power spikes or glitches during power transfer.The MAX630’s low-battery detector monitors the line-powered +5V, and the LBD output can be used to shut down unnecessary sections of the system during power failures. Alternatively, the low-battery detector could monitor the NiCad battery voltage and provide warning of power loss when the battery is nearly discharged.Unlike battery backup systems that use 9V batteries,this circuit does not need +12V or +15V to recharge the battery. Consequently, it can be used to provide +5V backup on modules or circuit cards that only have 5V available.9V Battery Life ExtenderFigure 7’s circuit provides a minimum of 7V until the 9V battery voltage falls to less than 2V. When the battery voltage is above 7V, the MAX630’s I C pin is low, putting it into the shutdown mode that draws only 10nA. When the battery voltage falls to 7V, the MAX8212 voltage detector’s output goes high, enabling the MAX630. The MAX630 then maintains the output voltage at 7V, even as the battery voltage falls below 7V. The LBD is used to decrease the oscillator frequency when the battery voltage falls to 3V, thereby increasing the output cur-rent capability of the circuit.CMOS Micropower Step-Up Switching Regulator 10______________________________________________________________________________________Figure 4. High-Power 3V to 5V Converter with ShutdownNote that this circuit (with or without the MAX8212) can be used to provide 5V from four alkaline cells. The initial volt-age is approximately 6V, and the output is maintained at 5V even when the battery voltage falls to less than 2V.Dual-Tracking RegulatorA MAX634 inverting regulator is combined with a MAX630 in F igure 8 to provide a dual-tracking ±15Voutput from a 9V battery. The reference for the -15V output is derived from the positive output through R3and R4. Both regulators are set to maximize output power at low-battery voltage by reducing the oscillator frequency, through LBR, when V BATT falls to 7.2V.MAX630/MAX4193Switching Regulator______________________________________________________________________________________11Figure 5. 3V to 5V Converter with Low-Battery Frequency ShiftFigure 7. Battery Life Extension Down to 3V InFigure 6. Uninterruptable +5V SupplyM A X 630/M A X 4193Switching Regulator 12______________________________________________________________________________________Table 2. Maxim DC-DC ConvertersFigure 8. ±12V Dual-Tracking RegulatorMAX630/MAX4193Switching Regulator______________________________________________________________________________________13Package InformationFor the latest package outline information, go to /packages .Chip TopographyLBR17I CV FB6230.089"(2.26mm)C XL XM A X 630/M A X 4193Switching Regulator Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.14____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600©2008 Maxim Integrated Productsis a registered trademark of Maxim Integrated Products, Inc.Revision History。

MAX6387XS26D7-T中文资料元器件交易网19-1839; Rev 1; 04/01SC70, Single/Dual Low-Voltage, Low-Power µP Reset CircuitsGeneral DescriptionFeaturesThe MAX6381�CMAX6390 microprocessor (µP) supervisorycircuits monitor power supply voltages from +1.8V tooFactory-Set Reset Threshold Voltages Ranging+5.0V while consuming only 3µA of supply current atfrom +1.58V to+4.63V in Approximately 100mV+1.8V. Whenever VCCfalls below the factory-set resetIncrementsthresholds, the reset output asserts and remains assert-o±2.5% Reset Threshold Accuracy Overed for a minimum reset timeout period after VCCrisesTemperature (-40°C to +125°C)above the reset threshold. Re set thresholds are availablefrom +1.58V to +4.63V, in approximately 100mV incre-oSeven Reset Timeout Periods Available: 1ms,ments. Seven minimum reset timeout delays ranging20ms, 140ms, 280ms, 560ms, 1120ms, from 1ms to 1200ms are available.1200ms (min)The MAX6381/MAX6384/MAX6387 have a push-pullo3 Reset Output Optionsactive-low reset output. The MAX6382/MAX6385/Active-Low Push-PullMAX6388 have a push-pull active-high reset output,Active-High Push-Pulland theMAX6383/MAX6386/MAX6389/MAX6390 have an open-drain active-low reset output. TheActive-Low Open-DrainMAX6384/MAX6385/MAX6386 also feature aoReset Output State Guaranteed Valid debounced manual reset input (with internal pullupDown to VCC= 1Vresistor). The MAX6387/MAX6388/MAX6389 have anauxiliary input for monitoring a second voltage. TheoManual Reset Input(MAX6384/MAX6385/MAX6386)MAX6390 offers a manual reset input with a longer VoAuxiliary RESETINreset timeout period (1120ms or 1200ms) and ashorterCC(MAX6387/MAX6388/MAX6389)manual reset timeout (140ms or 150ms).oVCCReset Timeout (1120ms or 1200ms)/ManualThe MAX6381/MAX6382/MAX6383 are available in 3-pinReset Timeout (140ms or 150ms) (MAX6390)SC70 packages and the MAX6384�CMAX6390 are avail-able in 4-pin SC70 packages.oNegative-Going VCCTransient Immunity________________________ApplicationsoLow Power Consumption of 6µA at +3.6V and 3µA at +1.8VComputersoPin Compatible withControllersMAX809/MAX810/MAX803/MAX6326/MAX6327/Intelligent InstrumentsMAX6328/MAX6346/MAX6347/MAX6348, Critical µP and µC Power Monitoringand MAX6711/MAX6712/MAX6713Portable/Battery-Powered EquipmentoTiny 3-Pin SC70 and 4-Pin SC70 PackagesDual Voltage SystemsPin ConfigurationsNote:Insert reset threshold suffix (see Reset Threshold table)after "XR" or "XS". Insert reset timeout delay (see Reset TimeoutDelay table) after "D" to complete the part number. Samplestock is generally held on standard versions only (seeStandard Versions table). Standard versions have an orderincrement requirement of 2500 pieces. Nonstandard versionshave an order increment requirement of 10,000 pieces.Contact factory for availability of nonstandard versions.*MAX6390 is available with D4 or D7 timing only.Ordering Information continuedat end of data sheet.Typical Operating Circuit appears at end of data sheet.Selector Guide appears at end of data sheet.________________________________________________________________Maxim Integrated Products1For pricing, delivery, and ordering information,please contactMaxim/Dallas Direct!at 1-888-629-4642, or visit Maxim’s website at .MAX6381�CMAX6390SC70, Single/Dual Low-Voltage, Low-Power µP Reset CircuitsMAX6381�CMAX6390ABSOLUTE MAXIMUM RATINGSVCC to GND..........................................................-0.3Vto +6.0VRESETOpen-Drain Output....................................-0.3V to+6.0VRESET, RESET (Push-Pull Output).............-0.3V to (VCC+ 0.3V)MR, RESET IN.............................................-0.3V to (VCC+ 0.3V)Input Current (VCC).............................................................20mAOutput Current (All Pins).....................................................20mAContinuous Power Dissip ation (TA= +70°C)3-Pin SC70 (derate 2.9mW/°C above +70°C)........235mW4-Pin SC70 (derate 3.1mW/°C above +70°C)........245mWOperating Temperature Range.........................-40°C to +125°CStorage Temperature Range.............................-65°C to +150°CLead Temperature (soldering, 10s).................................+300°CStresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functionaloperation of the device at these or any other conditions beyondthose indicated in the operational sections of the specifications is not implied. Exposure toabsolute maximum rating conditions for extended periodsmay affect device reliability.ELECTRICAL CHARACTERISTICSSC70, Single/Dual Low-Voltage, Low-Power µP Reset Circuits_______________________________________________________________________________________3MAX6381�CMAX6390SC70, Single/Dual Low-Voltage, Low-Power µP Reset CircuitsMAX6381�CMAX6390Typical Operating Characteristics(TA = +25°C, unless otherwise noted.)SUPPLY CURRENT vs. TEMPERATURE(NO LOAD)POWER-DOWN RESET DELAYvs. TEMPERATURENORMALIZED RESET TIMEOUT PERIOD8SUPPLY CURRENT (µA)7654321041POWER-DOWN RESET DELAY (µs)393735333129271.061.041.021.000.980.960.94-40-25-105203550658095110125TEMPERATURE (°C)25-40-25-105203550658095110125TEMPERATURE (°C)-40-25-105203550658095110125TEMPERATURE (°C)NORMALIZED RESET THRESHOLDvs. TEMPERATUREMAX6381/90 toc04OUTPUT VOLTAGE LOWvs. SINK CURRENTOUTPUT VOLTAGE HIGHvs. SOURCE CURRENT1.020NORMALIZED RESETTHRESHOLD1.0151.0101.0051.0000.9950.9900.985 1.21.00.8VOL (V)0.60.40.20036ISINK (mA)93.02.52.0VOH (V)1.51.00.500250500750100012500.990-40-25-105203550658095110125TEMPERATURE (°C)121500ISOURCE (µA)MAXIMUM TRANSIENT DURATIONvs. RESET COMPARATOR OVERDRIVERESET IN TO RESET DELAYvs. TEMPERATURE5.35.1RESET IN DELAY (µs)4.94.74.54.34.13.93.73.5MAX6381/90 toc08500MAXIMUM TRANSIENT DURATION (µs)450400350300250200150100501101005.51000-40-25-105203550658095110125TEMPERATURE (°C)RESET COMPARATOR OVERDRIVE, VTH - VCC (mV)4_____________________________________________________________________________ _________MAX6381/90 toc039NORMALIZED POWER-UP RESET TIMEOUTvs. TEMPERATURE1.0843SC70, Single/Dual Low-Voltage, Low-Power µP Reset Circuits______________________________________________________________________________ _________5MAX6381�CMAX6390SC70, Single/Dual Low-Voltage, Low-Power µP ResetCircuitsMAX6381�CMAX6390Detailed DescriptionRESET OutputA µP reset input starts the µP in a known state. TheseµP supervisory circuits assert reset to prevent codeexecution errors during power-up, power-down, orbrownout conditions.Reset asserts when VCCis below the reset threshold;once VCCexceeds the reset threshold, an internal timerkeeps the reset output asserted for the reset timeoutperiod. After this interval, reset output deasserts. Resetoutput is guaranteed to be in the correct logic state forVCC≥1V.Manual Reset Input (MAX6384/MAX6385/MAX6386/MAX6390)Man y µP-based products require manual reset capabil-ity, allowing the operator, a test technician, or externallogic circuitry to initiate a reset. A logic low on MRasserts reset. Reset remains asserted while MRis low,and for the reset active timeout period (tRP) after MRreturns high. This input has an internal 63k pullupresistor (1.35k for MAX6390), so it can be left uncon-nected if it is not used. MRcan be driven with TTL orCMOS logic levels, or with open-drain/collector outputs.Connect a normally open momentary switch from MRtoGND to create a manual-reset function; externaldebounce circuitry is not required. If MRis driven fromlong cables or if the device is used in anoisy environ-ment, connecting a 0.1µF capacitor from MRto GNDprovides additional noise immunity.RESET IN Comparator(MAX6387/MAX6388/MAX6389)RESET IN is compared to an internal +1.27V reference.If the voltage at RESET IN is less than 1.27V, resetasserts. Use the RESET IN comparator as a user-adjustable reset detector or as a secondary power-sup-ply monitor by implementing a resistor-divider at RESETIN (shown in Figure 1). Reset asserts when either VCCor RESET IN falls below its respective threshold volt-age. Use the following equation to set the threshold:VINTH= VTHRST (R1/R2 + 1)where VTHRST= +1.27V. To simplify the resistor selec-tion, choose a value of R2 and calculate R1:R1 = R2 [(VINTH/VTHRST) - 1]Since the input current at RESET IN is 50nA (max),large values can be used for R2 with no significant lossin accuracy.___________Applications InformationIn addition to issuing a reset to the µP during power-up,power-down, and brownout conditions, theMAX6381�CMAX6390 are relatively immune to short dura-tion negative-going VCCtransients (glitches).The Typical Operating Characteristicssection shows theMaximum Transient Durations vs. Reset ComparatorOverdrive, for which the MAX6381�CMAX6390 do notgenerate a reset pulse. This graph was generated usingNegative-Going VCCTransients6_____________________________________________________________________________ __________SC70, Single/Dual Low-Voltage, Low-Power µP Reset CircuitsMAX6381�CMAX6390not work with the open-drain outputs of theMAX6383/MAX6386/MAX6389/MAX6390. The resistorvalue used is not critical, but it must be small enoughnot to load the reset output when VCCis above the resetthreshold. For most applications, 100k is adequate.a negative-going pulse applied to VCC, starting above theactual reset threshold and ending below it by the magni-tude indicated (reset comparator overdrive). The graphindicates the typical maximum pulse width a negative-going VCCtransient may have without causing a resetpulse to be issued. As the magnitude of the transientincreases (goes farther below the reset threshold), themaximum allowable pulse width decreases. A 0.1µFcapacitor mounted as close as possible to VCCprovidesadditional transient immunity.The MAX6381�CMAX6390 are guaranteed to operateproperly down to VCC= 1V.In applications that requirevalid reset levels down to VCC= 0, a pulldown resistor toactive-low outputs (push/pull only, Figure 2) and apullup resistorto active-high outputs (push/pull only) willensure that the reset line isvalid while the reset outputcan no longer sink or source current. This scheme doesEnsuring a Valid RESETOutput Down to VCC= 0_______________________________________________________________________________________7SC70, Single/Dual Low-Voltage, Low-Power µP ResetCircuitsMAX6381�CMAX6390Pin Configurations (continued)*MRis for MAX6384/MAX6385/MAX6386/MAX6390**RESET IN is forMAX6387/MAX6388/MAX6389( ) are for MAX6382/MAX6385/MAX6388Chip InformationTRANSISTOR COUNT: 647PROCESS: BiCMOSSC70, Single/Dual Low-Voltage, Low-Power µP Reset CircuitsOrdering InformationNote:Insert reset threshold suffix (see Reset Threshold table)after "XR" or "XS". Insert reset timeout delay (see Reset TimeoutDelay table) after "D" to complete the part number. Samplestock is generally held on standard versions only (seeStandard Versions table). Standard versions have an orderincrement requirement of 2500 pieces. Nonstandard versionshave an order increment requirement of 10,000 pieces.Contact factory for availability of nonstandard versions.*MAX6390 is available with D4 or D7 timing only.______________________________________________________________________________ _________9MAX6381�CMAX6390SC70, Single/Dual Low-Voltage, Low-Power µP ResetCircuitsMAX6381�CMAX6390Package Information10____________________________________________________________________________ __________SC70, Single/Dual Low-Voltage, Low-Power µP Reset CircuitsPackage Information (continued)Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses areimplied. Maxim reserves the right to change the circuitry and specifications without notice at any time.Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600____________________11©2001 Maxim Integrated ProductsPrinted USAis a registered trademark of Maxim Integrated Products.MAX6381�CMAX6390感谢您的阅读，祝您生活愉快。

特征内置软启动：4ms优化的Hiccup Mode 设计，以提高效率和降低待机功耗正常工作时无音频噪声设计 固定工作频率：50KHz 内置斜波补偿电路低的启动电流和工作电流 内置前沿消隐电路 欠压锁定保护 过载保护(OLP) 过压保护(OVP)保护解除后自动恢复功能应用电池充电器数码相机、摄像机适配器VCR, SVR, DVD & DVCD 播放器电源机顶盒电源个人电脑、服务器辅助电源 开放式开关电源概要CRE635X 集成了专门的电流模式PWM 控制器和高压功率MOSFET ，适用于24W 以内的高性能、低待机功耗、低成本的离线式反激开关电源中。

CRE635X 具有软启动的功能。

为了保证芯片正常工作特针对各种故障设计了一系列完善的具有可恢复功能的保护措施，包括VDD 欠压锁定保护（UVLO ）、过压保护（OVP ）及箝位、逐周期电流限制（OCP ）、过载保护（OLP ）和图腾柱输出驱动高箝位等。

芯片内置的频率抖动和图腾柱栅极软驱动技术可容易地获得良好的EMI 性能。

CRE635X 具有 DIP-8L & SOP-8L 两种封装可供选择。

内部方框图管脚定义（DIP-8L & SOP-8L）典型应用管脚说明GND 地。

FB 反馈输入引脚。

PWM控制器的占空比由此引脚上的反馈电压和SENSE引脚上 的检测电压共同决定。

VDD-G 内部栅极驱动电源输入。

SENSE 电流采样输入。

VDD 芯片电源。

Drain 高压MOSFET漏极。

此引脚连接在变压器初级侧线圈一端。

线圈另一端接整 流输入电容阳极。

绝对最大额定值漏极电压（关闭状态） -0.3V to 600VVDD电压-0.3V to 30VVDD-G输入电压-0.3V to 30VVDD箝位连续电流10 mAFB输入电压-0.3V to 7VSense输入电压-0.3V to 7V最小/最大工作结温度T j-20。

to 150。

用于Peltier模块的集成温度控制器概论MAX1978 / MAX1979是用于Peltier热电冷却器（TEC）模块的最小, 最安全, 最精确完整的单芯片温度控制器。

片上功率FET和热控制环路电路可最大限度地减少外部元件, 同时保持高效率。

可选择的500kHz / 1MHz开关频率和独特的纹波消除方案可优化元件尺寸和效率, 同时降低噪声。

内部MOSFET的开关速度经过优化, 可降低噪声和EMI。

超低漂移斩波放大器可保持±0.001°C的温度稳定性。

直接控制输出电流而不是电压, 以消除电流浪涌。

独立的加热和冷却电流和电压限制提供最高水平的TEC保护。

MAX1978采用单电源供电, 通过在两个同步降压调节器的输出之间偏置TEC, 提供双极性±3A输出。

真正的双极性操作控制温度, 在低负载电流下没有“死区”或其他非线性。

当设定点非常接近自然操作点时, 控制系统不会捕获, 其中仅需要少量的加热或冷却。

模拟控制信号精确设置TEC 电流。

MAX1979提供高达6A的单极性输出。

提供斩波稳定的仪表放大器和高精度积分放大器, 以创建比例积分（PI）或比例积分微分（PID）控制器。

仪表放大器可以连接外部NTC或PTC热敏电阻, 热电偶或半导体温度传感器。

提供模拟输出以监控TEC温度和电流。

此外, 单独的过热和欠温输出表明当TEC温度超出范围时。

片上电压基准为热敏电阻桥提供偏置。

MAX1978 / MAX1979采用薄型48引脚薄型QFN-EP 封装, 工作在-40°C至+ 85°C温度范围。

采用外露金属焊盘的耐热增强型QFN-EP封装可最大限度地降低工作结温。

评估套件可用于加速设计。

应用光纤激光模块典型工作电路出现在数据手册的最后。

WDM, DWDM激光二极管温度控制光纤网络设备EDFA光放大器电信光纤接口ATE特征♦尺寸最小, 最安全, 最精确完整的单芯片控制器♦片上功率MOSFET-无外部FET♦电路占用面积<0.93in2♦回路高度<3mm♦温度稳定性为0.001°C♦集成精密积分器和斩波稳定运算放大器♦精确, 独立的加热和冷却电流限制♦通过直接控制TEC电流消除浪涌♦可调节差分TEC电压限制♦低纹波和低噪声设计♦TEC电流监视器♦温度监控器♦过温和欠温警报♦双极性±3A输出电流（MAX1978）♦单极性+ 6A输出电流（MAX1979）订购信息* EP =裸焊盘。

General DescriptionThe MAX6365–MAX6368 supervisory circuits simplify power-supply monitoring, battery-backup control func-tions, and memory write protection in microprocessor (µP) systems. The circuits significantly improve the size,accuracy, and reliability of modern systems with an ultra-small integrated solution.These devices perform four basic system functions:1) Provide a µP reset output during V CC supply power-up, power-down, and brownout conditions.2) Internally control V CC to backup-battery switching tomaintain data or low-power operation for CMOS RAM, CMOS µPs, real-time clocks, and other digital logic when the main supply fails.3) Provide memory write protection through internalchip-enable gating during supply or processor faults.4) Include one of the following options: a manual resetinput (MAX6365), a watchdog timer function (MAX6366), a battery-on output (MAX6367), or an auxiliary user-adjustable reset input (MAX6368).The MAX6365–MAX6368 operate from V CC supply volt-ages as low as 1.2V. The factory preset reset threshold voltages range from 2.32V to 4.63V (see the Ordering Information ). In addition, each part is offered in three reset output versions: push-pull active low, open-drain active low, or open-drain active high (see the Selector Guide ). The MAX6365–MAX6368 are available in minia-ture 8-pin SOT23 packages.ApplicationsCritical µP/µC Power Portable/Battery-Monitoring Powered Equipment Fax Machines Set-Top Boxes Industrial Control POS EquipmentComputers/ControllersFeatures♦Low +1.2V Operating Supply Voltage (V CC or V BATT )♦Precision Monitoring of +5.0V, +3.3V, +3.0V, and +2.5V Power-Supply Voltages♦On-Board Gating of Chip-Enable Signals, 1.5ns Propagation Delay♦Debounced Manual Reset Input (MAX6365)♦Watchdog Timer, 1.6s Timeout (MAX6366)♦Battery-On Output Indicator (MAX6367)♦Auxiliary User-Adjustable RESET IN (MAX6368)♦Low 10µA Quiescent Supply Current ♦Three Available Output StructuresPush-Pull RESET Open-Drain RESET Open-Drain RESET♦RESET/RESET Valid Down to 1.2V Guaranteed (V CC or V BATT )♦Power-Supply Transient Immunity ♦150ms min Reset Timeout Period ♦Miniature 8-Pin SOT23 PackageMAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating________________________________________________________________Maxim Integrated Products1Pin Configurations19-1658; Rev 3; 12/05For pricing, delivery, and ordering information,please contact Maxim/Dallas Direct!at 1-888-629-4642, or visit Maxim’s website at .Ordering Information*These parts offer a choice of reset threshold voltages. From the Reset Threshold Ranges table, insert the desired threshold volt-age code in the blank to complete the part number. SOT parts come in tape-and-reel only and must be ordered in 2500-piece increments. See Device Marking Codes for a complete parts list,including SOT top marks and standard threshold versions. See Selector Guide for a listing of device features.Devices are available in both leaded and lead-free packaging.Specify lead-free by replacing “-T” with “+T” when ordering.Typical Operating Circuit appears at end of data sheet.M A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable GatingABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICS(V = +2.4V to +5.5V, V = +3.0V, CE IN = V , reset not asserted, T = -40°C to +85°C. Typical values are at T = +25°C,Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.Terminal Voltages (with respect to GND)V CC , BATT, OUT.......................................................-0.3V to +6V RESET (open drain), RESET (open drain)................-0.3V to +6V BATT ON, RESET (push-pull), RESET IN,WDI, CE IN, CE OUT...........................-0.3V to (V OUT + 0.3V)MR ..............................................................-0.3V to (V CC + 0.3V)Input CurrentV CC Peak ..............................................................................1A V CC Continuous.............................................................250mA BATT Peak.....................................................................250mA BATT Continuous.............................................................40mAGND...............................................................................75mA Output CurrentOUT...............................Short-Circuit Protected for up to 10s RESET, RESET , BATT ON, CE OUT...............................20mA Continuous Power Dissipation (T A = +70°C)8-Pin SOT23 (derate 8.75mW/°C above +70°C)........700mW Operating Temperature Range ...........................-40°C to +85°C Storage Temperature Range.............................-65°C to +150°C Junction Temperature .....................................................+150°C Lead Temperature (soldering, 10s).................................+300°CMAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating_______________________________________________________________________________________3ELECTRICAL CHARACTERISTICS (continued)(V CC = +2.4V to +5.5V, V BATT = +3.0V, CE IN = V CC , reset not asserted, T A = -40°C to +85°C. Typical values are at T A = +25°C,M A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating 4_______________________________________________________________________________________Typical Operating Characteristics(T A = +25°C, unless otherwise noted.)8109121115141316-400-2020406080SUPPLY CURRENTvs. TEMPERATURE (NO LOAD)TEMPERATURE (°C)S U P P L Y C U R R E N T (µA )0.20.60.40.81.01.2BATTERY SUPPLY CURRENT (BACKUP MODE) vs. TEMPERATURETEMPERATURE (°C)B A T T E R Y S U P P L YC U R R E N T (µA )-402040-200608021437658-40-2020406080BATT-TO-OUT ON-RESISTANCEvs. TEMPERATURETEMPERATURE (°C)B A T T -T O -O U T O N -R E S I S T A NC E (Ω)ELECTRICAL CHARACTERISTICS (continued)(V= +2.4V to +5.5V, V = +3.0V, CE IN = V , reset not asserted, T = -40°C to +85°C. Typical values are at T = +25°C,Note 2:V BATT can be 0 anytime, or V CC can go down to 0 if V BATT is active (except at startup).Note 3:RESET is pulled up to OUT. Specifications apply for OUT = V CC or OUT = BATT.Note 4:The chip-enable resistance is tested with V CC = V TH(MAX)and CE IN = V CC / 2.MAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating_______________________________________________________________________________________5Typical Operating Characteristics (continued)(T A = +25°C, unless otherwise noted.)00.40.20.80.61.21.01.4-4020-20406080V CC TO OUT ON-RESISTANCEvs. TEMPERATURETEMPERATURE (°C)V C C T O O U T O N -R E S I S T A N C E (Ω)190195205200210RESET TIMEOUT PERIOD vs. TEMPERATUREM A X 6365/8-05TEMPERATURE (°C)R E S E T T I M E O U T P E R I O D (m s )-402040-206080301575604513512010590TEMPERATURE (°C)P R O P A G A T I O N D E L A Y (µs )-402040-206080V CC TO RESET PROPAGATION DELAYvs. TEMPERATURE2.03.02.55.04.54.03.5RESET THRESHOLD vs. TEMPERATURETEMPERATURE (°C)T H R E S H O L D (V )-402040-206080110010100010,000MAXIMUM TRANSIENT DURATION vs. RESET THRESHOLD OVERDRIVERESET THRESHOLD OVERDRIVE V TH - V CC (mV)M A X I M U M T R A N S I E N T D U R A T I O N (µs )40030035025020005015010003215498761000.5 1.0 1.5 2.0 2.5 3.03.5BATTERY SUPPLY CURRENT vs. SUPPLY VOLTAGEV CC (V)B A T T E R Y S U P P L YC U R R E N T (µA )M A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating 6_______________________________________________________________________________________1.2341.2351.236MAX6368RESET IN THRESHOLD vs. TEMPERATUREM A X 6365/8 -10TEMPERATURE (°C)V R T H (V )-402040-2060801.01.91.61.32.82.52.2MAX6368RESET IN TO RESET PROPAGATION DELAYvs. TEMPERATURETEMPERATURE (°C)P R O P A G A T I O N D E L A Y (µs )-402040-206080013245C LOAD (pF)P R O P A G A T I O N D E L A Y (n s )10050150200CHIP-ENABLE PROPAGATION DELAY vs. CE OUT LOAD CAPACITANCE515102025-40-2020406080TEMPERATURE (°C)C E I N T O C E O U T O N -R E S I S T A N C E (Ω)CE IN TO CE OUT ON-RESISTANCEvs. TEMPERATURE1.01.31.21.11.51.41.91.81.71.62.0-40-2020406080TEMPERATURE (°C)W A T C H D O G T I M E O U T P E R I O D (s )MAX6366WATCHDOG TIMEOUT PERIODvs. TEMPERATURETypical Operating Characteristics (continued)(T A = +25°C, unless otherwise noted.)MAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating_______________________________________________________________________________________7M A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating 8_______________________________________________________________________________________Detailed DescriptionThe Typical Operating Circuit shows a typical connec-tion for the MAX6365–MAX6368. OUT powers the static random-access memory (SRAM). If V CC is greater than the reset threshold (V TH ), or if V CC is lower than V TH but higher than V BATT , V CC is connected to OUT. If V CC is lower than V TH and V CC is less than V BATT ,BATT is connected to OUT. OUT supplies up to 150mA from V CC . In battery-backup mode, an internal MOSFET connects the backup battery to OUT. The on-resistance of the MOSFET is a function of backup-battery voltage and is shown in the BATT-to-OUT On-Resistance vs.Temperature graph in the T ypical Operating Char-acteristics .Chip-Enable Signal GatingThe MAX6365–MAX6368 provide internal gating of CE signals to prevent erroneous data from being written toCMOS RAM in the event of a power failure. During nor-mal operation, the CE gate is enabled and passes all CE transitions. When reset asserts, this path becomes disabled, preventing erroneous data from corrupting the CMOS RAM. All of these devices use a series trans-mission gate from CE IN to CE OUT. The 2ns propaga-tion delay from CE IN to CE OUT allows the devices to be used with most µPs and high-speed DSPs.During normal operation, CE IN is connected to CE OUT through a low on-resistance transmission gate.This is valid when reset is not asserted. If CE IN is high when reset is asserted, CE OUT remains high regard-less of any subsequent transitions on CE IN during the reset event.If CE IN is low when reset is asserted, CE OUT is held low for 12µs to allow completion of the read/write oper-ation (F igure 1). After the 12µs delay expires, the CEFunctional DiagramMAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating_______________________________________________________________________________________9OUT goes high and stays high regardless of any sub-sequent transitions on CE IN during the reset event.When CE OUT is disconnected from CE IN, CE OUT is actively pulled up to OUT.The propagation delay through the chip-enable circuit-ry depends on both the source impedance of the drive to CE IN and the capacitive loading at CE OUT. The chip-enable propagation delay is production tested from the 50% point of CE IN to the 50% point of CE OUT, using a 50Ωdriver and 50pF load capacitance.Minimize the capacitive load at CE OUT to minimize propagation delay, and use a low-output-impedance driver.Backup-Battery SwitchoverIn a brownout or power failure, it may be necessary to preserve the contents of the RAM. With a backup bat-tery installed at BATT, the MAX6365–MAX6368 auto-matically switch the RAM to backup power when V CC falls. The MAX6367 has a BATT ON output that goes high in battery-backup mode. These devices require two conditions before switching to battery-backup mode:1) V CC must be below the reset threshold.2) V CC must be below V BATT .Table 1 lists the status of the inputs and outputs in bat-tery-backup mode. The devices do not power up if the only voltage source is on BATT. OUT only powers upfrom V CC at startup.Many µP-based products require manual reset capabili-ty, allowing the user or external logic circuitry to initiate a reset. For the MAX6365, a logic low on MR asserts reset.Reset remains asserted while MR is low and for a mini-mum of 150ms (t RP ) after it returns high. MR has an inter-nal 20k Ωpullup resistor to V CC . This input can be driven with TTL/CMOS logic levels or with open-drain/collector outputs. Connect a normally open momentary switch from MR to GND to create a manual reset function; exter-nal debounce circuitry is not required. If MR is driven from long cables or the device is used in a noisy environ-ment, connect a 0.1µF capacitor from MR to GND to pro-vide additional noise immunity.Figure 1. Reset and Chip-Enable TimingM A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating 10______________________________________________________________________________________Watchdog Input (MAX6366 Only)The watchdog monitors µP activity through the watch-dog input (WDI). If the µP becomes inactive, reset asserts. To use the watchdog function, connect WDI to a bus line or µP I/O line. A change of state (high to low,low to high, or a minimum 100ns pulse) resets the watchdog timer. If WDI remains high or low for longer than the watchdog timeout period (t WD ), the internal watchdog timer runs out and a reset pulse is triggered for the reset timeout period (t RP ). The internal watchdog timer clears whenever reset asserts or whenever WDI sees a rising or falling edge. If WDI remains in either a high or low state, a reset pulse asserts periodically after every t WD (Figure 2).BATT ON Indicator (MAX6367 Only)BATT ON is a push-pull output that drives high when in battery-backup mode. BATT ON typically sinks 3.2mA at 0.1V saturation voltage. In battery-backup mode, this terminal sources approximately 10µA from OUT. Use BATT ON to indicate battery-switchover status or to supply base drive to an external pass transistor for higher current applications (Figure 3).RESET IN Comparator (MAX6368 Only)RESET IN is compared to an internal 1.235V reference.If the voltage at RESET IN is less than 1.235V, reset asserts. Use the RESET IN comparator as an undervolt-age detector to signal a failing power supply or as a secondary power-supply reset monitor.To program the reset threshold (V RTH ) of the secondary power supply, use the following (see Typical Operating Circuit ):V RTH = V REF (R1 / R2 + 1)where V REF = 1.235V. To simplify the resistor selection,choose a value for R2 and calculate R1:R1 = R2 [(V RTH / V REF ) - 1]Since the input current at RESET IN is 25nA (max),large values (up to 1M Ω) can be used for R2 with no significant loss in accuracy. For example, in the Typical Operating Circuit , the MAX6368 monitors two supply voltages. To monitor the secondary 5V logic or analog supply with a 4.60V nominal programmed reset thresh-old, choose R2 = 100k Ω, and calculate R1 = 273k Ω.Reset OutputA µP’s reset input starts the µP in a known state. The MAX6365–MAX6368 µP supervisory circuits assert a reset to prevent code-execution errors during power-up, power-down, and brownout conditions. RESET is guaranteed to be a logic low or logic high, depending on the device chosen (see the Ordering Information ).RESET or RESET asserts when V CC is below the reset threshold and for at least 150ms (t RP ) after V CC rises above the reset threshold. RESET or RESET also asserts when MR is low (MAX6365) and when RESET IN is less than 1.235V (MAX6368). The MAX6366 watch-dog function will cause RESET (or RESET ) to assert in pulses following a watchdog timeout (Figure 2).Applications InformationOperation Withouta Backup Power SourceThe MAX6365–MAX6368 provide battery-backup func-tions. If a backup power source is not used, connect BATT to GND and OUT to V CC .Watchdog Software ConsiderationsOne way to help the watchdog timer monitor the soft-ware execution more closely is to set and reset the watchdog at different points in the program rather than pulsing the watchdog input periodically. F igure 4shows a flow diagram in which the I/O driving theFigure 2. MAX6366 Watchdog Timeout Period and Reset Active TimeMAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating______________________________________________________________________________________11watchdog is set low in the beginning of the program,set high at the beginning of every subroutine or loop,and set low again when the program returns to the beginning. If the program should hang in any subrou-tine, the problem would be quickly corrected.Replacing the Backup BatteryWhen V CC is above V TH , the backup power source can be removed without danger of triggering a reset pulse.The device does not enter battery-backup mode when V CC stays above the reset threshold voltage.Negative-Going V CC TransientsThese supervisors are relatively immune to short-dura-tion, negative-going V CC transients. Resetting the µP when V CC experiences only small glitches is usually not desirable.The T ypical Operating Characteristics section has a Maximum Transient Duration vs. Reset Threshold Overdrive graph for which reset is not asserted. The graph was produced using negative-going V CC pulses,starting at V CC and ending below the reset threshold by the magnitude indicated (reset threshold overdrive).The graph shows the maximum pulse width that a neg-ative-going V CC transient can typically have without triggering a reset pulse. As the amplitude of the tran-sient increases (i.e., goes further below the reset threshold), the maximum allowable pulse width decreases. Typically, a V CC transient that goes 100mV below the reset threshold and lasts for 30µs will not trig-ger a reset pulse.A 0.1µF bypass capacitor mounted close to the V CC pin provides additional transient immunity.M A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating 12______________________________________________________________________________________standard versions only. Contact factory for availability of nonstandard versions.MAX6365–MAX6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating______________________________________________________________________________________13Pin Configurations (continued)M A X 6365–M A X 6368SOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable Gating 14______________________________________________________________________________________Typical Operating CircuitChip InformationTRANSISTOR COUNT: 729PROCESS: CMOSSOT23, Low-Power µP Supervisory Circuits with Battery Backup and Chip-Enable GatingMAX6365–MAX6368Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________15©2005 Maxim Integrated ProductsPrinted USAis a registered trademark of Maxim Integrated Products, Inc.Package Information(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to /packages .)。