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MAX5457EEE+T中文资料

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General DescriptionThe MAX5456/MAX5457 dual, logarithmic taper digital potentiometers feature a simple pushbutton interface that controls volume and balance in audio applications.Each potentiometer has 32 tap points and replaces mechanical potentiometers. Refer to the MAX5408–MAX5411 data sheet for SPI™ versions of the MAX5456/MAX5457.Use the MAX5456/MAX5457 digital inputs with momen-tary contact single-pole/single-throw (SPST) pushbutton switches. Each input includes internal debounce cir-cuitry and a 50k Ωpullup resistor.The MAX5456/MAX5457 advance the wiper setting once per button push. Maxim’s proprietary SmartWiper™ con-trol eliminates the need for a microcomputer to increase the wiper transition rate. Holding the control input low for more than 1s advances the wiper at a rate of 4Hz for 4s and 16Hz per second thereafter.The MAX5456/MAX5457 provide temperature coeffi-cients of 50ppm/°C end-to-end and 5ppm/°C ratiomet-ric and a nominal resistance of 10k Ωper potentiometer.An integrated click/pop suppression feature minimizes the audible noise generated by wiper transitions. The typical total harmonic distortion plus noise (THD+N) for these devices is 0.01%.The MAX5457 features a 3-button interface with a MODE input that toggles between volume- and balance-control modes. An LED output indicates volume or bal-ance mode. The MAX5456 features a 4-button interface with separate inputs for up and down volume controls and left and right balance controls.The MAX5456/MAX5457 are available in 16-pin QSOP and 16-pin TQFN packages and are specified over the extended (-40°C to +85°C) temperature range.ApplicationsStereo Volume ControlFading and Balancing Stereo Signals Stereo Blending and MixingFeatures♦SmartWiper Control Provides Accelerated Wiper Motion ♦Debounced Pushbutton Interface with Internal Pullup Resistors♦Logarithmic Taper with 2dB Steps Between Taps ♦Single +2.7V to +5.5V or Dual ±2.7V Supply Operation♦Low 0.5µA Standby Supply Current ♦Clickless Switching♦10k ΩEnd-to-End Fixed Resistance Value ♦Mute Function to -90dB (typ)♦Power-On Reset to -12dB Wiper Position ♦32 Tap Positions for Each Wiper ♦Small 16-Pin QSOP/TQFN PackagesMAX5456/MAX5457Stereo Audio Taper Potentiometerswith Pushbutton Interface________________________________________________________________Maxim Integrated Products 1Ordering Information19-3490; Rev 1; 12/05For pricing, delivery, and ordering information,please contact Maxim/Dallas Direct!at 1-888-629-4642, or visit Maxim’s website at .Typical Application Circuits and Selector Guide appear at end of data sheet.SPI is a trademark of Motorola, Inc.SmartWiper is a trademark of Maxim Integrated Products, Inc.Pin Configurations*Future product—contact factory for availability.M A X 5456/M A X 5457Stereo Audio Taper Potentiometers with Pushbutton Interface 2_______________________________________________________________________________________ABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICS(V DD = V LOGIC = +2.7V to +5.5V, V SS = 0V, GND = 0V, V H_ = V DD , V L_ = V SS , T A = T MIN to T MAX . Typical values are at T A = +25°C,unless otherwise specified.) (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.(MAX5456) SHDN , MUTE , VOLUP , VOLDN ,BAL_to GND.....................................-0.3V to (V LOGIC + 0.3V)(MAX5457) SHDN , MUTE , UP /BAL1, DN /BAL0, MODE ,MODE_IND to GND...........................-0.3V to (V LOGIC + 0.3V)H_, L_, and W_ to V SS ..............................-0.3V to (V DD + 0.3 V)V DD to GND..............................................................-0.3V to +6V V DD to V SS ................................................................-0.3V to +6V V LOGIC to GND.........................................................-0.3V to +6V V LOGIC to V SS ...........................................................-0.3V to +6V V SS to GND............................................................-3.0V to +0.3VPeak Current into H_, L_, and W_.......................................±1mA Average Current into H_, L_, and W_..............................±500µA Input and Output Latchup Immunity...............................±200mA Continuous Power Dissipation (T A = +70°C)16-Pin QSOP (derate 8.3mW/°C above +70°C)........666.7mW 16-Pin TQFN (derate 16.9mW/°C above +70°C)....1349.1mW Operating Temperature Range ...........................-40°C to +85°C Junction Temperature......................................................+150°C Storage Temperature Range.............................-60°C to +150°C Lead Temperature (soldering, 10s).................................+300°CMAX5456/MAX5457Stereo Audio Taper Potentiometerswith Pushbutton Interface_______________________________________________________________________________________3Note 1:Parameters are 100% production tested at +85°C and limits through temperature are guaranteed by design.Note 2:Supply current measured with the supply on and a button pushed.Note 3:Supply current measured with the power on, no button pushed, and the wiper position fixed.Note 4:This is the measured current with SHDN low and MODE_IND unconnected.ELECTRICAL CHARACTERISTICS (continued)(V DD = V LOGIC = +2.7V to +5.5V, V SS = 0V, GND = 0V, V H_ = V DD , V L_ = V SS , T A = T MIN to T MAX . Typical values are at T A = +25°C,unless otherwise specified.) (Note 1)M A X 5456/M A X 5457Stereo Audio Taper Potentiometers with Pushbutton Interface 4_______________________________________________________________________________________Typical Operating Characteristics(V DD = V LOGIC = +2.7V to +5.5V, V SS = 0V, GND = 0V, V H _ = V DD , V L _ = V SS , T A = T MIN to T MAX . Typical values are at T A = +25°C,unless otherwise specified.)WIPER RESISTANCE vs. WIPER VOLTAGEWIPER VOLTAGE (V)W I P E R R E S I S T A N C E (Ω) 4.53.5 4.01.5 2.0 2.5 3.01.0650700750800850900950100010501100115012006000.5 5.0ATTENUATION vs. TAP POSITIONM A X 5456/7 t o c 02TAP POSITION A T T E N U A T I O N (d B )282420161284-60-50-40-30-20-100-70032END-TO-END RESISTANCE % CHANGEvs. TEMPERATUREM A X 5456/7 t p c 03TEMPERATURE (°C)E N D -T O -E N D R E S I S T A N C E C H A N G E (%)603510-15-0.4-0.3-0.2-0.100.10.20.30.40.5-0.5-4085ACTIVE SUPPLY CURRENT vs. TEMPERATUREA C T I V E S U P P L Y C U R R E N T (µA )185190195200210205215220180TEMPERATURE (°C)603510-15-4085WIPER SWITCHING TRANSIENT(TIMING OUT)10ms/div5V/div1V/divVOLUPWIPER TRANSITION FROM -2dB to 0dBV H_ = V DD V L_ = 0WIPER SWITCHING TRANSIENT (SUPPRESSION CIRCUIT ACTIVE)4ms/div 5V/div2V/divVOLUPWIPER TRANSITION FROM -2dB to 0dBV H _ = SQUARE WAVE FROM V DD TO V SS , V L _ = V DD / 2LOGIC SUPPLY CURRENT vs. LOGIC SUPPLY VOLTAGELOGIC SUPPLY VOLTAGE (V)L O G I C S U P P L Y C U R R E N T (µA )204060801001201401601802005.2 5.54.2 4.73.73.22.7MAX5456/MAX5457Stereo Audio Taper Potentiometerswith Pushbutton Interface_______________________________________________________________________________________5FREQUENCY RESPONSEFREQUENCY (kHz)R E S P O N S E (d B )1001010.1-6-4-202-80.011000TOTAL HARMONIC DISTORTION PLUS NOISEvs. FREQUENCYFREQUENCY (Hz)T H D +N (%)10,00010001000.0010.010.11101000.000110100,000DIGITAL SUPPLY CURRENT vs. DIGITAL INPUT VOLTAGEM A X 5456/7 t o c 10DIGITAL INPUT VOLTAGE (V)D I G I T A L S U P P L Y C U R RE N T (µA )43211002003004005006007008009001000005POWER-SUPPLY REJECTION RATIOvs. FREQUENCYFREQUENCY (kHz)P S R R (d B )10010-80-70-60-50-40-30-20-100-9011000LOGIC SUPPLY CURRENT vs. TEMPERATURETEMPERATURE (°C)L O G I C S U P P L Y C U R R E N T (m A )603510-15141142143144145146147148149150140-4085Typical Operating Characteristics (continued)(V DD = V LOGIC= +2.7V to +5.5V, V SS = 0V, GND = 0V, V H _ = V DD , V L _ = V SS , T A = T MIN to T MAX . Typical values are at T A = +25°C,unless otherwise specified.)0.050.100.150.200.250.300LOGIC SUPPLY CURRENT vs. LOGIC SUPPLY VOLTAGELOGIC SUPPLY VOLTAGE (V)L O G I C S U P P L Y C U R R E N T (µA )5.2 5.54.24.73.73.22.7WIPER-TO-END TERMINAL RESISTANCEvs. TAP POSITIONTAP POSITIONN O M I N A L E N D -T O -E N D R E S I S T A N C E (%R H L )241682550751000032SPECTRAL NOISE DENSITYM A X 5456 t o c 13FREQUENCY (kHz)N O I S E (n V R M S /√H z )1010.11234567891000.01100M A X 5456/M A X 5457Stereo Audio Taper Potentiometers with Pushbutton InterfaceMAX5456/MAX5457Stereo Audio Taper Potentiometerswith Pushbutton Interface_______________________________________________________________________________________7Detailed DescriptionThe MAX5456/MAX5457 dual, logarithmic taper digital potentiometers feature a simple pushbutton interface that controls volume and balance in audio applications. Each potentiometer has 32 tap points and replaces mechanical potentiometers (see the Functional Diagrams ).Up and Down InterfaceThe MAX5456/MAX5457 interface with momentary con-tact SPST switches. All switch inputs are internally debounced and pulled up to V LOGIC through 50k Ωresistors. The wiper setting advances once per button press up to 1s. Maxim’s SmartWiper control circuitry allows the wiper to advance at a rate of 4Hz when an input is held low from 1s up to 4s, and at a rate of 16Hz if the contact is maintained for greater than 4s (see Table 2). The SmartWiper control eliminates the need for a microcomputer to increase the wiper transition rate.The MAX5456 features independent control inputs for volume and balance control while the MAX5457 MODE input toggles between volume and balance control.Each transition of MODE from high to low toggles the MAX5457 between volume-control and balance-control modes. MODE is internally pulled high with a 50k Ωresistor to V LOGIC.Volume ControlIn volume-control mode, the MAX5456/MAX5457s’wipers move simultaneously, maintaining the balance separation between each wiper (Figure 3a).When either wiper reaches the maximum tap position (position closest to H_), further commands to increase the volume are ignored. Balance separation is main-tained in the maximum volume configuration (Figure 3b).When either wiper reaches the minimum tap position (position closest to L_), further commands to decrease the volume adjust the other wiper until it also reaches the minimum tap position (Figure 3c).Increasing the volume from this minimum position restores the original balance separation of the wipers (Figure 3d).When both wipers are in the 31st tap position (-62dB attenuation), further commands to VOLDN place the wipers in the mute position (see Table 1). VOLUP or MUTE pulses return wipers to position 31.M A X 5456/M A X 5457Stereo Audio Taper Potentiometers with Pushbutton InterfaceMAX5456/MAX5457Stereo Audio Taper Potentiometerswith Pushbutton Interface_______________________________________________________________________________________9Balance ControlIn balance-control mode, the MAX5456/MAX5457adjust the balance between channel 0 and channel 1while maintaining the set volume. For example, if the volume of channel 0 equals the volume of channel 1,forcing the balance towards channel 1 increases the attenuation of channel 0 (Figure 4a). If channel 1 is at a higher attenuation than channel 0, adjusting the bal-ance to channel 1 moves channel 1’s wiper up to the same wiper position as channel 0 before attenuating channel 0 (Figure 4b).To control the wiper quickly with a logic signal, main-tain pulses at least 22.5ms wide and separated by at least 40ms.Figure 4. Balance-Control OperationM A X 5456/M A X 5457Stereo Audio Taper Potentiometers with Pushbutton Interface10______________________________________________________________________________________Click/Pop SuppressionThe click/pop suppression feature reduces the audible noise (clicks and pops) that result from wiper transitions.The MAX5456/MAX5457 minimize this noise by allowing the wiper position changes only when V H_= V L_. Thus,the wiper changes position only when the voltage at L_ is the same as the voltage at the corresponding H_. Each wiper has its own suppression and timeout circuitry (see Figure 5a). The MAX5456/MAX5457 change wiper posi-tion after 32ms or when V H_= V L , whichever occurs first (see Figure 5b).The suppression circuitry monitors left and right chan-nels separately. In volume-control mode, when the first wiper changes position, the second wiper has 32ms to change or it will be forced to change.Power-On ResetThe power-on comparators monitor V DD - V SS and V LOGIC - GND. A power-on reset is initiated when either of the supplies is brought back to normal operating voltage. The power-on-reset feature sets both wipers to -12dB. Power-on reset places the MAX5457 in volume-control mode.Figure 5a. Wiper Transition Timing DiagramMAX5456/MAX5457Stereo Audio Taper Potentiometerswith Pushbutton Interface______________________________________________________________________________________11Figure 5b. Wiper Transition Timing DiagramShutdown, SHDNUpon entering shutdown mode, the MAX5456/MAX5457store the last wiper settings. The wipers move to the L_end of the resistor string, and the H_ end of the resistor string disconnects from the signal input. Terminating shutdown mode restores the wipers to their previous settings (see Figure 2). Shutdown does not affect the state of MODE_IND.Mute Function, MUTEThe MAX5456/MAX5457 feature a mute function. Success-ive pulses on MUTE toggle its setting. Activating the mutefunction forces both wipers to maximum attenuation (-90dB typ). Deactivating the mute function returns the wipers to their previous settings. Pressing VOLUP also deactivates mute, setting the wipers to their previous positions. MUTE is internally pulled high with a 50k Ωresistor to VLOG IC. When both wipers are in the 31st tap position (-62dB attenuation), further commands to VOLDN place the wipers in the mute position (see Table 1). VOLUP or MUTE pulses return the wipers to position 31.M A X 5456/M A X 5457Stereo Audio Taper Potentiometers with Pushbutton Interface 12______________________________________________________________________________________Mode Control, MODEThe MAX5457 MODE input toggles between volume-and balance-control modes. Force MODE low to toggle between volume-control and balance-control modes.For example, driving MODE low once while in volume-control mode, switches the MAX5457 to balance-con-trol mode. Driving mode low once again, switches the MAX5457 back to volume-control mode. MODE is inter-nally pulled high with a 50k Ωresistor to V LOGIC . The MAX5457 powers up in volume-control mode.Mode Indicator, MODE_INDMODE_IND is the volume-control and balance-control mode indicator with an open-drain output. Connect MODE_IND to an LED through a pullup resistor to V LOGIC .When the LED is on, the MAX5457 is in balance-control mode. When the LED is off, the MAX5457 is in volume-control mode. See the Mode Control, MODE sec-tion for more detail on switching between modes.Shutdown does not affect the state of MODE_IND.Multiple Button PushesThe MAX5456/MAX5457 do not respond to simultane-ous button pushes. Pushing more than one button at the same time stops the wipers in their present states. Only a single button push configures the device. Additionally,a 40ms blocking period affects all other inputs when releasing any input forced low. The MAX5456/MAX5457do not respond to any logic input until the blocking peri-od ends. If multiple wiper-control buttons are pressed,all wiper-control connections must be released before the part will respond to further commands.Applications InformationStereo Volume/Balance ControlFigure 6 shows a volume/balance application using the MAX5457. The op amp is connected in a follower (non-inverting gain) configuration to isolate the potentiome-ter’s wiper impedance from the load and provide drive capability. Connect the W_ of the MAX5457 to the posi-tive input of a noninverting gain amp. The pushbutton potentiometers attenuate the input signals. Use the MODE input to switch between volume-control and bal-ance-control modes.MAX5456/MAX5457Stereo Audio Taper Potentiometerswith Pushbutton Interface______________________________________________________________________________________13Figure 6. Volume/Balance ControlM A X 5456/M A X 5457Stereo Audio Taper Potentiometers with Pushbutton Interface 14______________________________________________________________________________________Pin Configurations (continued)Chip InformationTRANSISTOR COUNT: 15,395PROCESS: CMOS*Future product—contact factory for availability.MAX5456/MAX5457Stereo Audio Taper Potentiometerswith Pushbutton InterfaceTypical Application Circuit (Single Supply)Typical Application Circuit (Dual Supplies)M A X 5456/M A X 5457Stereo Audio Taper Potentiometers with Pushbutton Interface 16______________________________________________________________________________________Functional DiagramsMAX5456/MAX5457Stereo Audio Taper Potentiometerswith Pushbutton Interface______________________________________________________________________________________17Functional Diagrams (continued)M A X 5456/M A X 5457Stereo Audio Taper Potentiometers with Pushbutton Interface 18______________________________________________________________________________________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 .)MAX5456/MAX5457Stereo Audio Taper Potentiometerswith Pushbutton Interface______________________________________________________________________________________19Package 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 .)M A X 5456/M A X 5457Stereo Audio Taper Potentiometers with Pushbutton Interface 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.20____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600©2005 Maxim Integrated ProductsPrinted USAis a registered trademark of Maxim Integrated Products, Inc.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 .)。

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MAX471MAX472的中文资料大全

MAX471MAX472的中文资料大全

M A X471M A X472的中文资料大全(总4页)-本页仅作为预览文档封面，使用时请删除本页-MAX471/MAX472的特点、功能美国美信公司生产的精密高端电流检测放大器是一个系列化产品，有MAX471/MA X472、 MAX4172/MAX4173等。

它们均有一个电流输出端，可以用一个电阻来简单地实现以地为参考点的电流/电压的转换，并可工作在较宽电压内。

MAX471/MAX472具有如下特点：●具有完美的高端电流检测功能；●内含精密的内部检测电阻（MAX471）；●在工作温度范围内，其精度为2%；●具有双向检测指示，可监控充电和放电状态；●内部检测电阻和检测能力为3A，并联使用时还可扩大检测电流范围；●使用外部检测电阻可任意扩展检测电流范围（MAX472）；●最大电源电流为100μA；●关闭方式时的电流仅为5μA；●电压范围为3～36V；●采用8脚DIP/SO/STO三种封装形式。

MAX471/MAX472的引脚排列如图1所示，图2所示为其内部功能框图。

表1为MAX471/MAX472的引脚功能说明。

MAX471的电流增益比已预设为500μA/A，由于2kΩ的输出电阻（ROUT）可产生1V/A的转换，因此±3A时的满度值为3V.用不同的ROUT电阻可设置不同的满度电压。

但对于MAX471，其输出电压不应大于VRS+。

对于MAX472，则不能大于。

MAX471引脚图如图１所示，MAX472引脚图如图２所示。

MAX471/MAX472的引脚功能说明引脚名称功能MAX471MAX47211SHDN关闭端。

正常运用时连接到地。

当此端接高电平时，电源电流小于5μA2，3-RS+内部电流检测电阻电池（或电源端）。

“+”仅指示与SIGN输出有关的流动方向。

封装时已将2和3连在了一起-2空脚-3RG1增益电阻端。

通过增益设置电阻连接到电流检测电阻的电池端44GND地或电池负端55SIGN集电极开路逻辑输出端。

MAX3237EEAI+T中文资料

MAX3237EEAI+T中文资料

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,or visit Maxim's website at .General DescriptionThe MAX3222E/MAX3232E/MAX3237E/MAX3241E/MAX3246E +3.0V-powered EIA/TIA-232 and V.28/V.24communications interface devices feature low power con-sumption, high data-rate capabilities, and enhanced electrostatic-discharge (ESD) protection. The enhanced ESD structure protects all transmitter outputs and receiver inputs to ±15kV using IEC 1000-4-2 Air-G ap Discharge, ±8kV using IEC 1000-4-2 Contact Discharge (±9kV for MAX3246E), and ±15kV using the Human Body Model. The logic and receiver I/O pins of the MAX3237E are protected to the above standards, while the transmit-ter output pins are protected to ±15kV using the Human Body Model.A proprietary low-dropout transmitter output stage delivers true RS-232 performance from a +3.0V to +5.5V power supply, using an internal dual charge pump. The charge pump requires only four small 0.1µF capacitors for opera-tion from a +3.3V supply. Each device guarantees opera-tion at data rates of 250kbps while maintaining RS-232output levels. The MAX3237E guarantees operation at 250kbps in the normal operating mode and 1Mbps in the MegaBaud™ operating mode, while maintaining RS-232-compliant output levels.The MAX3222E/MAX3232E have two receivers and two transmitters. The MAX3222E features a 1µA shutdown mode that reduces power consumption in battery-pow-ered portable systems. The MAX3222E receivers remain active in shutdown mode, allowing monitoring of external devices while consuming only 1µA of supply current. The MAX3222E and MAX3232E are pin, package, and func-tionally compatible with the industry-standard MAX242and MAX232, respectively.The MAX3241E/MAX3246E are complete serial ports (three drivers/five receivers) designed for notebook and subnotebook computers. The MAX3237E (five drivers/three receivers) is ideal for peripheral applications that require fast data transfer. These devices feature a shut-down mode in which all receivers remain active, while consuming only 1µA (MAX3241E/MAX3246E) or 10nA (MAX3237E).The MAX3222E, MAX3232E, and MAX3241E are avail-able in space-saving SO, SSOP, TQFN and TSSOP pack-ages. The MAX3237E is offered in an SSOP package.The MAX3246E is offered in the ultra-small 6 x 6 UCSP™package.ApplicationsBattery-Powered Equipment PrintersCell PhonesSmart Phones Cell-Phone Data Cables xDSL ModemsNotebook, Subnotebook,and Palmtop ComputersNext-Generation Device Features♦For Space-Constrained ApplicationsMAX3228E/MAX3229E: ±15kV ESD-Protected, +2.5V to +5.5V, RS-232 Transceivers in UCSP ♦For Low-Voltage or Data Cable ApplicationsMAX3380E/MAX3381E: +2.35V to +5.5V, 1µA, 2Tx/2Rx, RS-232 Transceivers with ±15kV ESD-Protected I/O and Logic PinsMAX3222E/MAX3232E/MAX3237E/MAX3241E †/MAX3246E±15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V ,Up to 1Mbps, True RS-232 Transceivers________________________________________________________________Maxim Integrated Products 119-1298; Rev 11; 10/07Ordering Information continued at end of data sheet.*Dice are tested at T A = +25°C, DC parameters only.**EP = Exposed paddle.Pin Configurations, Selector Guide, and Typical Operating Circuits appear at end of data sheet.MegaBaud and UCSP are trademarks of Maxim Integrated Products, Inc.†Covered by U.S. Patent numbers 4,636,930; 4,679,134;4,777,577; 4,797,899; 4,809,152; 4,897,774; 4,999,761; and other patents pending.M A X 3222E /M A X 3232E /M A X 3237E /M A X 3241E †/M A X 3246EUp to 1Mbps, True RS-232 TransceiversABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICS(V CC = +3V to +5.5V, C1–C4 = 0.1µF, T A = T MIN to T MAX , unless otherwise noted. Typical values are at T A = +25°C.) (Notes 3, 4)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 +6V V+ to GND (Note 1)..................................................-0.3V to +7V V- to GND (Note 1)...................................................+0.3V to -7V V+ + |V-| (Note 1).................................................................+13V Input Voltages T_IN, EN , SHDN , MBAUD to GND ........................-0.3V to +6V R_IN to GND.....................................................................±25V Output Voltages T_OUT to GND...............................................................±13.2V R_OUT, R_OUTB (MAX3241E)................-0.3V to (V CC + 0.3V)Short-Circuit Duration, T_OUT to GND.......................Continuous Continuous Power Dissipation (T A = +70°C)16-Pin SSOP (derate 7.14mW/°C above +70°C)..........571mW 16-Pin TSSOP (derate 9.4mW/°C above +70°C).......754.7mW 16-Pin TQFN (derate 20.8mW/°C above +70°C).....1666.7mW 16-Pin Wide SO (derate 9.52mW/°C above +70°C).....762mW 18-Pin Wide SO (derate 9.52mW/°C above +70°C).....762mW 18-Pin PDIP (derate 11.11mW/°C above +70°C)..........889mW 20-Pin TQFN (derate 21.3mW/°C above +70°C)........1702mW 20-Pin TSSOP (derate 10.9mW/°C above +70°C)........879mW 20-Pin SSOP (derate 8.00mW/°C above +70°C)..........640mW 28-Pin SSOP (derate 9.52mW/°C above +70°C)..........762mW 28-Pin Wide SO (derate 12.50mW/°C above +70°C).............1W 28-Pin TSSOP (derate 12.8mW/°C above +70°C)......1026mW 32-Lead Thin QFN (derate 33.3mW/°C above +70°C)..2666mW 6 x 6 UCSP (derate 12.6mW/°C above +70°C).............1010mW Operating Temperature Ranges MAX32_ _EC_ _...................................................0°C to +70°C MAX32_ _EE_ _.................................................-40°C to +85°C Storage Temperature Range.............................-65°C to +150°C Lead Temperature (soldering, 10s).................................+300°C Bump Reflow Temperature (Note 2)Infrared, 15s..................................................................+200°C Vapor Phase, 20s..........................................................+215°C Note 1:V+ and V- can have maximum magnitudes of 7V, but their absolute difference cannot exceed 13V.Note 2:This device is constructed using a unique set of packaging techniques that impose a limit on the thermal profile the devicecan be exposed to during board-level solder attach and rework. This limit permits only the use of the solder profiles recom-mended in the industry-standard specification, JEDEC 020A, paragraph 7.6, Table 3 for IR/VPR and convection reflow.Preheating is required. Hand or wave soldering is not allowed.MAX3222E/MAX3232E/MAX3237E/MAX3241E †/MAX3246EUp to 1Mbps, True RS-232 Transceivers_______________________________________________________________________________________3M A X 3222E /M A X 3232E /M A X 3237E /M A X 3241E †/M A X 3246EUp to 1Mbps, True RS-232 Transceivers4_______________________________________________________________________________________TIMING CHARACTERISTICS—MAX3237E(V CC = +3V to +5.5V, C1–C4 = 0.1µF, T A = T MIN to T MAX , unless otherwise noted. Typical values are at T A = +25°C.) (Note 3)±10%. MAX3237E: C1–C4 = 0.1µF tested at +3.3V ±5%, C1–C4 = 0.22µF tested at +3.3V ±10%; C1 = 0.047µF, C2, C3, C4 =0.33µF tested at +5.0V ±10%. MAX3246E; C1-C4 = 0.22µF tested at +3.3V ±10%; C1 = 0.22µF, C2, C3, C4 = 0.54µF tested at 5.0V ±10%.Note 4:MAX3246E devices are production tested at +25°C. All limits are guaranteed by design over the operating temperature range.Note 5:The MAX3237E logic inputs have an active positive feedback resistor. The input current goes to zero when the inputs are atthe supply rails.Note 6:MAX3241EEUI is specified at T A = +25°C.Note 7:Transmitter skew is measured at the transmitter zero crosspoints.TIMING CHARACTERISTICS—MAX3222E/MAX3232E/MAX3241E/MAX3246EMAX3222E/MAX3232E/MAX3237E/MAX3241E †/MAX3246EUp to 1Mbps, True RS-232 Transceivers_______________________________________________________________________________________5-6-4-202460MAX3237ETRANSMITTER OUTPUT VOLTAGE vs. LOAD CAPACITANCE (MBAUD = GND)LOAD CAPACITANCE (pF)T R A N S M I T T E R O U T P U T V O L T A G E (V )10001500500200025003000531-1-3-5-6-2-42046-5-31-135010001500500200025003000LOAD CAPACITANCE (pF)T R A N S M I T T E R O U T P U T V O L T A G E (V )MAX3237ETRANSMITTER OUTPUT VOLTAGEvs. LOAD CAPACITANCE-7.5-5.0-2.502.55.07.5MAX3237ETRANSMITTER OUTPUT VOLTAGE vs. LOAD CAPACITANCE (MBAUD = V CC )LOAD CAPACITANCE (pF)T R A N S M I T T E R O U T P U T V O L T A G E (V )500100015002000__________________________________________Typical Operating Characteristics(V CC = +3.3V, 250kbps data rate, 0.1µF capacitors, all transmitters loaded with 3k Ωand C L , T A = +25°C, unless otherwise noted.)-6-5-4-3-2-10123456010002000300040005000MAX3241ETRANSMITTER OUTPUT VOLTAGEvs. LOAD CAPACITANCELOAD CAPACITANCE (pF)T R A N S M I T T E R O U T P U T V O L T A G E (V)302010405060020001000300040005000MAX3241EOPERATING SUPPLY CURRENT vs. LOAD CAPACITANCELOAD CAPACITANCE (pF)S U P P L Y C U R R E N T (m A )04286121014010002000300040005000MAX3241ESLEW RATE vs. LOAD CAPACITANCEM A X 3237E t o c 05LOAD CAPACITANCE (pF)S L E W R A T E (V /μs )-6-5-4-3-2-10123456010002000300040005000MAX3222E/MAX3232ETRANSMITTER OUTPUT VOLTAGEvs. LOAD CAPACITANCELOAD CAPACITANCE (pF)T R A N S M I T T E R O U T P UT V O L T A G E (V )624108141216010002000300040005000MAX3222E/MAX3232ESLEW RATE vs. LOAD CAPACITANCELOAD CAPACITANCE (pF)S L E W R A T E (V /μs)2520155103530404520001000300040005000MAX3222E/MAX3232E OPERATING SUPPLY CURRENT vs. LOAD CAPACITANCELOAD CAPACITANCE (pF)S U P P L Y C U R R E N T (m A )M A X 3222E /M A X 3232E /M A X 3237E /M A X 3241E †/M A X 3246EUp to 1Mbps, True RS-232 Transceivers6_______________________________________________________________________________________Typical Operating Characteristics (continued)(V CC = +3.3V, 250kbps data rate, 0.1µF capacitors, all transmitters loaded with 3k Ωand C L , T A = +25°C, unless otherwise noted.)20604080100MAX3237ETRANSMITTER SKEW vs. LOAD CAPACITANCE(MBAUD = V CC )LOAD CAPACITANCE (pF)100015005002000T R A N S M I T T E R S K E W (n s )-6-2-42046-3-51-1352.03.03.52.54.04.55.0SUPPLY VOLTAGE (V)T R A N S M I T T E R O U T P U T V O L T A G E (V )MAX3237ETRANSMITTER OUTPUT VOLTAGE vs. SUPPLY VOLTAGE (MBAUD = GND)10203040502.0MAX3237E SUPPLY CURRENT vs. SUPPLY VOLTAGE (MBAUD = GND)SUPPLY VOLTAGE (V)S U P P L Y C U R R E N T (m A )3.03.52.54.04.55.0MAX3246ETRANSMITTER OUTPUT VOLTAGEvs. LOAD CAPACITANCELOAD CAPACITANCE (pF)T R A N S M I T T E R O U T P U T V O L T A G E (V )4000300010002000-5-4-3-2-101234567-65000468101214160MAX3246ESLEW RATE vs. LOAD CAPACITANCELOAD CAPACITANCE (pF)S L EW R A T E (V /μs )200030001000400050001020304050600MAX3246EOPERATING SUPPLY CURRENT vs. LOAD CAPACITANCEM A X 3237E t o c 17LOAD CAPACITANCE (pF)S U P P L Y C U R R EN T (m A )1000200030004000500055453525155024681012MAX3237ESLEW RATE vs. LOAD CAPACITANCE(MBAUD = GND)LOAD CAPACITANCE (pF)S L E W R A T E (V /μs )10001500500200025003000010203050406070MAX3237ESLEW RATE vs. LOAD CAPACITANCE(MBAUD = V CC )LOAD CAPACITANCE (pF)S L E W R A T E (V /μs )5001000150020001020304050MAX3237ESUPPLY CURRENT vs. LOAD CAPACITANCE WHEN TRANSMITTING DATA (MBAUD = GND)LOAD CAPACITANCE (pF)S U P P L Y C U R R E N T (m A )10001500500200025003000MAX3222E/MAX3232E/MAX3237E/MAX3241E †/MAX3246EUp to 1Mbps, True RS-232 Transceivers_______________________________________________________________________________________7Pin DescriptionM A X 3222E /M A X 3232E /M A X 3237E /M A X 3241E †/M A X 3246EUp to 1Mbps, True RS-232 Transceivers8_______________________________________________________________________________________MAX3222E/MAX3232E/MAX3237E/MAX3241E †/MAX3246EUp to 1Mbps, True RS-232 Transceivers_______________________________________________________________________________________9Detailed DescriptionDual Charge-Pump Voltage ConverterThe MAX3222E/MAX3232E/MAX3237E/MAX3241E/MAX3246Es’ internal power supply consists of a regu-lated dual charge pump that provides output voltages of +5.5V (doubling charge pump) and -5.5V (inverting charge pump) over the +3.0V to +5.5V V CC range. The charge pump operates in discontinuous mode; if the output voltages are less than 5.5V, the charge pump is enabled, and if the output voltages exceed 5.5V, the charge pump is disabled. Each charge pump requires a flying capacitor (C1, C2) and a reservoir capacitor (C3, C4) to generate the V+ and V- supplies (Figure 1).RS-232 TransmittersThe transmitters are inverting level translators that con-vert TTL/CMOS-logic levels to ±5V EIA/TIA-232-compli-ant levels.The MAX3222E/MAX3232E/MAX3237E/MAX3241E/MAX3246E transmitters guarantee a 250kbps data rate with worst-case loads of 3k Ωin parallel with 1000pF,providing compatibility with PC-to-PC communication software (such as LapLink™). Transmitters can be par-alleled to drive multiple receivers or mice.The MAX3222E/MAX3237E/MAX3241E/MAX3246E transmitters are disabled and the outputs are forcedinto a high-impedance state when the device is in shut-down mode (SHDN = G ND). The MAX3222E/MAX3232E/MAX3237E/MAX3241E/MAX3246E permit the outputs to be driven up to ±12V in shutdown.The MAX3222E/MAX3232E/MAX3241E/MAX3246E transmitter inputs do not have pullup resistors. Connect unused inputs to GND or V CC . The MAX3237E’s trans-mitter inputs have a 400k Ωactive positive-feedback resistor, allowing unused inputs to be left unconnected.MAX3237E MegaBaud OperationFor higher-speed serial communications, the MAX3237E features MegaBaud operation. In MegaBaud operating mode (MBAUD = V CC ), the MAX3237E transmitters guarantee a 1Mbps data rate with worst-case loads of 3k Ωin parallel with 250pF for +3.0V < V CC < +4.5V. For +5V ±10% operation, the MAX3237E transmitters guarantee a 1Mbps data rate into worst-case loads of 3k Ωin parallel with 1000pF.RS-232 ReceiversThe receivers convert RS-232 signals to CMOS-logic output levels. The MAX3222E/MAX3237E/MAX3241E/MAX3246E receivers have inverting three-state outputs.Drive EN high to place the receiver(s) into a high-impedance state. Receivers can be either active or inactive in shutdown (Table 1).Figure 1. Slew-Rate Test CircuitsLapLink is a trademark of Traveling Software.M A X 3222E /M A X 3232E /M A X 3237E /M A X 3241E †/M A X 3246EUp to 1Mbps, True RS-232 Transceivers10______________________________________________________________________________________The complementary outputs on the MAX3237E/MAX3241E (R_OUTB) are always active, regardless of the state of EN or SHDN . This allows the device to be used for ring indicator applications without forward biasing other devices connected to the receiver outputs. This is ideal for systems where V CC drops to zero in shutdown to accommodate peripherals such as UARTs (Figure 2).MAX3222E/MAX3237E/MAX3241E/MAX3246E Shutdown ModeSupply current falls to less than 1µA in shutdown mode (SHDN = low). The MAX3237E’s supply current falls to10nA (typ) when all receiver inputs are in the invalid range (-0.3V < R_IN < +0.3). When shut down, the device’s charge pumps are shut off, V+ is pulled down to V CC , V- is pulled to ground, and the transmitter out-puts are disabled (high impedance). The time required to recover from shutdown is typically 100µs, as shown in Figure 3. Connect SHDN to V CC if shutdown mode is not used. SHDN has no effect on R_OUT or R_OUTB (MAX3237E/MAX3241E).±15kV ESD ProtectionAs with all Maxim devices, ESD-protection structures are incorporated to protect against electrostatic dis-charges encountered during handling and assembly.The driver outputs and receiver inputs of the MAX3222E/MAX3232E/MAX3237E/MAX3241E/MAX3246E have extra protection against static electricity. Maxim’s engineers have developed state-of-the-art structures to protect these pins against ESD of ±15kV without damage.The ESD structures withstand high ESD in all states:normal operation, shutdown, and powered down. After an ESD event, Maxim’s E versions keep working without latchup, whereas competing RS-232 products can latch and must be powered down to remove latchup.Furthermore, the MAX3237E logic I/O pins also have ±15kV ESD protection. Protecting the logic I/O pins to ±15kV makes the MAX3237E ideal for data cable applications.SHDN T2OUTT1OUT5V/div2V/divV CC = 3.3V C1–C4 = 0.1μFFigure 3. Transmitter Outputs Recovering from Shutdown or Powering UpMAX3222E/MAX3232E/MAX3237E/MAX3241E †/MAX3246EUp to 1Mbps, True RS-232 TransceiversESD protection can be tested in various ways; the transmitter outputs and receiver inputs for the MAX3222E/MAX3232E/MAX3241E/MAX3246E are characterized for protection to the following limits:•±15kV using the Human Body Model•±8kV using the Contact Discharge method specified in IEC 1000-4-2•±9kV (MAX3246E only) using the Contact Discharge method specified in IEC 1000-4-2•±15kV using the Air-G ap Discharge method speci-fied in IEC 1000-4-2Figure 4a. Human Body ESD Test ModelFigure 4b. Human Body Model Current WaveformFigure 5a. IEC 1000-4-2 ESD Test Model Figure 5b. IEC 1000-4-2 ESD Generator Current WaveformM A X 3222E /M A X 3232E /M A X 3237E /M A X 3241E †/M A X 3246EUp to 1Mbps, True RS-232 Transceiverscharacterized for protection to ±15kV per the Human Body Model.ESD Test ConditionsESD performance depends on a variety of conditions.Contact Maxim for a reliability report that documents test setup, test methodology, and test results.Human Body ModelFigure 4a shows the Human Body Model, and Figure 4b shows the current waveform it generates when dis-charged into a low impedance. This model consists of a 100pF capacitor charged to the ESD voltage of interest,which is then discharged into the test device through a 1.5k Ωresistor.IEC 1000-4-2The IEC 1000-4-2 standard covers ESD testing and performance of finished equipment; it does not specifi-cally refer to integrated circuits. The MAX3222E/MAX3232E/MAX3237E/MAX3241E/MAX3246E help you design equipment that meets level 4 (the highest level)of IEC 1000-4-2, without the need for additional ESD-protection components.The major difference between tests done using the Human Body Model and IEC 1000-4-2 is higher peak current in IEC 1000-4-2, because series resistance is lower in the IEC 1000-4-2 model. Hence, the ESD with-stand voltage measured to IEC 1000-4-2 is generally lower than that measured using the Human Body Model. Figure 5a shows the IEC 1000-4-2 model, and Figure 5b shows the current waveform for the ±8kV IEC 1000-4-2 level 4 ESD Contact Discharge test. The Air-G ap Discharge test involves approaching the device with a charged probe. The Contact Discharge method connects the probe to the device before the probe is energized.Machine ModelThe Machine Model for ESD tests all pins using a 200pF storage capacitor and zero discharge resis-tance. Its objective is to emulate the stress caused by contact that occurs with handling and assembly during manufacturing. All pins require this protection during manufacturing, not just RS-232 inputs and outputs.Therefore, after PC board assembly, the Machine Model is less relevant to I/O ports.Table 2. Required Minimum Capacitor ValuesFigure 6a. MAX3241E Transmitter Output Voltage vs. Load Current Per TransmitterTable 3. Logic-Family Compatibility with Various Supply VoltagesMAX3222E/MAX3232E/MAX3237E/MAX3241E †/MAX3246EUp to 1Mbps, True RS-232 TransceiversApplications InformationCapacitor SelectionThe capacitor type used for C1–C4 is not critical for proper operation; polarized or nonpolarized capacitors can be used. The charge pump requires 0.1µF capaci-tors for 3.3V operation. For other supply voltages, see Table 2 for required capacitor values. Do not use val-ues smaller than those listed in Table 2. Increasing the capacitor values (e.g., by a factor of 2) reduces ripple on the transmitter outputs and slightly reduces power consumption. C2, C3, and C4 can be increased without changing C1’s value. However, do not increase C1without also increasing the values of C2, C3, C4,and C BYPASS to maintain the proper ratios (C1 to the other capacitors).When using the minimum required capacitor values,make sure the capacitor value does not degradeexcessively with temperature. If in doubt, use capaci-tors with a larger nominal value. The capacitor’s equiv-alent series resistance (ESR), which usually rises at low temperatures, influences the amount of ripple on V+and V-.Power-Supply DecouplingIn most circumstances, a 0.1µF V CC bypass capacitor is adequate. In applications sensitive to power-supply noise, use a capacitor of the same value as charge-pump capacitor C1. Connect bypass capacitors as close to the IC as possible.Operation Down to 2.7VTransmitter outputs meet EIA/TIA-562 levels of ±3.7V with supply voltages as low as 2.7V.Figure 6b. Mouse Driver Test CircuitM A X 3222E /M A X 3232E /M A X 3237E /M A X 3241E †/M A X 3246EUp to 1Mbps, True RS-232 TransceiversFigure 7. Loopback Test CircuitT1IN T1OUTR1OUT5V/div5V/div5V/divV CC = 3.3V C1–C4 = 0.1μFFigure 8. MAX3241E Loopback Test Result at 120kbps T1INT1OUTR1OUT5V/div5V/div5V/divV CC = 3.3V, C1–C4 = 0.1μFFigure 9. MAX3241E Loopback Test Result at 250kbps+5V 0+5V 0-5V +5VT_INT_OUT5k Ω + 250pFR_OUTV CC = 3.3V C1–C4 = 0.1μFFigure 10. MAX3237E Loopback Test Result at 1000kbps (MBAUD = V CC )Transmitter Outputs Recoveringfrom ShutdownFigure 3 shows two transmitter outputs recovering from shutdown mode. As they become active, the two trans-mitter outputs are shown going to opposite RS-232 levels (one transmitter input is high; the other is low). Each transmitter is loaded with 3k Ωin parallel with 2500pF.The transmitter outputs display no ringing or undesir-able transients as they come out of shutdown. Note thatthe transmitters are enabled only when the magnitude of V- exceeds approximately -3.0V.Mouse DrivabilityThe MAX3241E is designed to power serial mice while operating from low-voltage power supplies. It has been tested with leading mouse brands from manu-facturers such as Microsoft and Logitech. The MAX3241E successfully drove all serial mice tested and met their current and voltage requirements.MAX3222E/MAX3232E/MAX3237E/MAX3241E †/MAX3246EUp to 1Mbps, True RS-232 TransceiversFigure 6a shows the transmitter output voltages under increasing load current at +3.0V. Figure 6b shows a typical mouse connection using the MAX3241E.High Data RatesThe MAX3222E/MAX3232E/MAX3237E/MAX3241E/MAX3246E maintain the RS-232 ±5V minimum transmit-ter output voltage even at high data rates. Figure 7shows a transmitter loopback test circuit. Figure 8shows a loopback test result at 120kbps, and Figure 9shows the same test at 250kbps. For Figure 8, all trans-mitters were driven simultaneously at 120kbps into RS-232 loads in parallel with 1000pF. For Figure 9, a single transmitter was driven at 250kbps, and all transmitters were loaded with an RS-232 receiver in parallel with 1000pF.The MAX3237E maintains the RS-232 ±5.0V minimum transmitter output voltage at data rates up to 1Mbps.Figure 10 shows a loopback test result at 1Mbps with MBAUD = V CC . For Figure 10, all transmitters were loaded with an RS-232 receiver in parallel with 250pF.Interconnection with 3V and 5V LogicThe MAX3222E/MAX3232E/MAX3237E/MAX3241E/MAX3246E can directly interface with various 5V logic families, including ACT and HCT CMOS. See Table 3for more information on possible combinations of inter-connections.UCSP ReliabilityThe UCSP represents a unique packaging form factor that may not perform equally to a packaged product through traditional mechanical reliability tests. UCSP reliability is integrally linked to the user’s assembly methods, circuit board material, and usage environ-ment. The user should closely review these areas when considering use of a UCSP package. Performance through Operating Life Test and Moisture Resistance remains uncompromised as the wafer-fabrication process primarily determines it.Mechanical stress performance is a greater considera-tion for a UCSP package. UCSPs are attached through direct solder contact to the user’s PC board, foregoing the inherent stress relief of a packaged product lead frame. Solder joint contact integrity must be consid-ered. Table 4 shows the testing done to characterize the UCSP reliability performance. In conclusion, the UCSP is capable of performing reliably through envi-ronmental stresses as indicated by the results in the table. Additional usage data and recommendations are detailed in the UCSP application note, which can be found on Maxim’s website at .Table 4. Reliability Test DataM A X 3222E /M A X 3232E /M A X 3237E /M A X 3241E †/M A X 3246EUp to 1Mbps, True RS-232 Transceivers__________________________________________________________Pin ConfigurationsMAX3222E/MAX3232E/MAX3237E/MAX3241E †/MAX3246EUp to 1Mbps, True RS-232 TransceiversPin Configurations (continued)M A X 3222E /M A X 3232E /M A X 3237E /M A X 3241E †/M A X 3246EUp to 1Mbps, True RS-232 Transceivers__________________________________________________Typical Operating CircuitsMAX3222E/MAX3232E/MAX3237E/MAX3241E †/MAX3246EUp to 1Mbps, True RS-232 Transceivers_____________________________________Typical Operating Circuits (continued)M A X 3222E /M A X 3232E /M A X 3237E /M A X 3241E †/M A X 3246EUp to 1Mbps, True RS-232 Transceivers_____________________________________Typical Operating Circuits (continued)MAX3222E/MAX3232E/MAX3237E/MAX3241E †/MAX3246EUp to 1Mbps, True RS-232 Transceivers______________________________________________________________________________________21Selector Guide___________________Chip InformationTRANSISTOR COUNT:MAX3222E/MAX3232E: 1129MAX3237E: 2110MAX3241E: 1335MAX3246E: 842PROCESS: BICMOSOrdering Information (continued)†Requires solder temperature profile described in the AbsoluteMaximum Ratings section. UCSP Reliability is integrally linked to the user’s assembly methods, circuit board material, and environment. Refer to the UCSP Reliability Notice in the UCSP Reliability section of this datasheet for more information.**EP = Exposed paddle.。

MAX4145EEE+T中文资料

MAX4145EEE+T中文资料


1
For free samples and the latest literature, visit or phone 1-800-998-8800. For small orders, phone 1-800-835-8769.
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High-Speed, Low-Distortion, Differential Line Receivers MAX4144/MAX4145/MAX4146
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (VCC to VEE) ..................................................12V Voltage on IN_, SHDN, REF, OUT, SENSE, RG_.................................(VEE - 0.3V) to (VCC + 0.3V) Short-Circuit Duration to Ground ........................................10sec Input Current (IN_, RG_)...................................................±10mA Output Current................................................................±120mA Continuous Power Dissipation (TA = +70°C) 14-Pin SO (derate 8.33mW/°C above +70°C)..............667mW 16-Pin QSOP (derate 8.33mW/°C above +70°C).........667mW Operating Temperature Range ...........................-40°C to +85°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10sec) .............................+300°C
MEMORY存储芯片MAX488EESA+T中文规格书

MEMORY存储芯片MAX488EESA+T中文规格书

±15kV ESD-Protected, Slew-Rate-Limited,Low-Power, RS-485/RS-422 Transceivers__________Function Tables (MAX481E/MAX483E/MAX485E/MAX487E/MAX1487E) Table 1. Transmitting Table 2. Receiving__________Applications Information The MAX481E/MAX483E/MAX485E/MAX487E–MAX491E and MAX1487E are low-power transceivers for RS-485 and RS-422 communications. These “E” versions of the MAX481, MAX483, MAX485, MAX487–MAX491, and MAX1487 provide extra protection against ESD. The rugged MAX481E, MAX483E, MAX485E, MAX497E–MAX491E, and MAX1487E are intended for harsh envi-ronments where high-speed communication is important. These devices eliminate the need for transient suppres-sor diodes and the associated high capacitance loading. The standard (non-“E”) MAX481, MAX483, MAX485, MAX487–MAX491, and MAX1487 are recommended for applications where cost is critical.The MAX481E, MAX485E, MAX490E, MAX491E, and MAX1487E can transmit and receive at data rates up to 2.5Mbps, while the MAX483E, MAX487E, MAX488E, and MAX489E are specified for data rates up to 250kbps. The MAX488E–MAX491E are full-duplex transceivers, while the MAX481E, MAX483E, MAX487E, and MAX1487E are half-duplex. In addition, driver-enable (DE) and receiver-enable (RE) pins are included on the MAX481E, MAX483E, MAX485E, MAX487E, MAX489E, MAX491E, and MAX1487E. When disabled, the driver and receiver outputs are high impedance.±15kV ESD Protection As with all Maxim devices, ESD-protection structures are incorporated on all pins to protect against electro-static discharges encountered during handling and assembly. The driver outputs and receiver inputs have extra protection against static electricity. Maxim’s engi-neers developed state-of-the-art structures to protect these pins against ESD of ±15kV without damage. The ESD structures withstand high ESD in all states: normal operation, shutdown, and powered down. After an ESD event, Maxim’s MAX481E, MAX483E, MAX485E, MAX487E–MAX491E, and MAX1487E keep working without latchup.ESD protection can be tested in various ways; the transmitter outputs and receiver inputs of this product family are characterized for protection to ±15kV using the Human Body Model.Other ESD test methodologies include IEC10004-2 con-tact discharge and IEC1000-4-2 air-gap discharge (for-merly IEC801-2).ESD Test Conditions ESD performance depends on a variety of conditions. Contact Maxim for a reliability report that documents test set-up, test methodology, and test results.Human Body Model F igure 4 shows the Human Body Model, and F igure 5 shows the current waveform it generates when dis-charged into a low impedance. This model consists of a 100pF capacitor charged to the ESD voltage of inter-est, which is then discharged into the test device through a 1.5kΩresistor.IEC1000-4-2 The IEC1000-4-2 standard covers ESD testing and per-formance of finished equipment; it does not specifically refer to integrated circuits (Figure 6).MAX481E/MAX483E/MAX485E/MAX487E–MAX491E/MAX1487E Maxim Integrated9±15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 TransceiversThe major difference between tests done using the Human Body Model and IEC1000-4-2 is higher peak current in IEC1000-4-2, because series resistance is lower in the IEC1000-4-2 model. Hence, the ESD with-stand voltage measured to IEC1000-4-2 is generally lower than that measured using the Human Body Model. Figure 7 shows the current waveform for the 8kV IEC1000-4-2 ESD contact-discharge test.The air-gap test involves approaching the device with a charged probe. The contact-discharge method connects the probe to the device before the probe is energized.Machine Model The Machine Model for ESD tests all pins using a 200pF storage capacitor and zero discharge resis-tance. Its objective is to emulate the stress caused by contact that occurs with handling and assembly during manufacturing. Of course, all pins require this protec-tion during manufacturing—not just inputs and outputs. Therefore,after PC board assembly,the Machine Model is less relevant to I/O ports.MAX487E/MAX1487E:128 Transceivers on the Bus The 48kΩ, 1/4-unit-load receiver input impedance of the MAX487E and MAX1487E allows up to 128 transceivers on a bus, compared to the 1-unit load (12kΩinput impedance) of standard RS-485 drivers (32 transceivers maximum). Any combination of MAX487E/MAX1487E and other RS-485 transceivers with a total of 32 unit loads or less can be put on the bus. The MAX481E, MAX483E, MAX485E, and MAX488E–MAX491E have standard 12kΩreceiver input impedance.MAX483E/MAX487E/MAX488E/MAX489E:Reduced EMI and Reflections The MAX483E and MAX487E–MAX489E are slew-rate limited, minimizing EMI and reducing reflections caused by improperly terminated cables. F igure 16 shows the driver output waveform and its Fourier analy-sis of a 150kHz signal transmitted by a MAX481E, MAX485E, MAX490E, MAX491E, or MAX1487E. High-frequency harmonics with large amplitudes are evident.F igure 17 shows the same information displayed for a MAX483E, MAX487E, MAX488E, or MAX489E transmit-ting under the same conditions. F igure 17’s high-fre-quency harmonics have much lower amplitudes, and the potential for EMI is significantly reduced.Low-Power Shutdown Mode(MAX481E/MAX483E/MAX487E) 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 0.5µA 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.F or the MAX481E, MAX483E, and MAX487E, the t ZH and t ZL enable times assume the part was not in the low-power shutdown state (the MAX485E, MAX488E–MAX491E, and MAX1487E can not be shut down). The t ZH(SHDN)and t ZL(SHDN)enable times assume the parts were shut down (see Electrical Characteristics).Figure 16. Driver Output Waveform and FFT Plot of MAX485E/MAX490E/MAX491E/MAX1487E Transmitting a 150kHz SignalFigure 17. Driver Output Waveform and FFT Plot ofMAX483E/MAX487E–MAX489E Transmitting a 150kHz SignalMAX481E/MAX483E/MAX485E/ MAX487E–MAX491E/MAX1487E 12。