APM9945KC-TUL中文资料

ST公司的L9945是八路MOSFET预驱动器,可配置成用于低边,高边,峰值和保持以及H桥负载的控制,设计用于12V(客车)和24V(商用车)电池系统.所有输出是PWM控制的,其中6个输出能安全驱动相关载荷,一个能激励需要专用使能引脚(EN6)的相关载荷.L9945提供控制两个单独H桥的功能,还能驱动多达两个需要”峰值保持”控制的负载.每个输出提供全部的诊断信息如对电池短路,对地短路和负载开路.而每个输出状态能不断通过专用SPI寄存器进行监测.器件满足AEC-Q100规范,3.3V和5V逻辑兼容I/O,工作电池电压3.8V到36V,工作的VDD电压4.5V-5.5V,L9945中的10位ADC通过SPI对电池和芯片温度进行测量.主要用在汽车电子.本文介绍了L9945主要特性,框图以及评估板EVAL-L9945及其应用框图,配置框图,电路图,材料清单和PCB设计图.The L9945 is an 8-channel MOSFET pre-driver configurable for low-side, high-side, peak and hold and H-Bridge load control. It is designed to comply with the requirements of 12 V (passenger vehicle) and 24 V(commercial vehicle) battery systems.All outputs can be PWM controlled. Six outputs are capable of driving safety relevant loads. One output can be dedicated to the actuation ofsafety relevant loads requiring a dedicated enable pin (EN6).The device offers the possibility of controlling two independent H-Bridges.The device can also drive up to two loads requiring "peak & hold"control strategy.The driver outputs are protected against short circuit condition.The device protects the external MOS in case of an overcurrent event.Each output provides full diagnostic information such as short tobattery, short to ground and open-load. Each output status can beconstantly monitored through dedicated SPI registers.The voltage slew rate of the external transistors 1-8 is controlled during turn ON and turn OFF in order to improve EMI behavior. A double,redundant, external disable source is available through DIS and NDIS pins in order to improve safety. The device is configurable via SPI through a 32-bit protocol.L9945主要特性:AEC-Q100 qualified12 V and 24 V battery systems compliance3.3 V and 5 V logic compatible I/O8-channel configurable MOSFET pre-driverHigh-side (N-channel and P-channel MOS)Low-side (N-channel MOS)H-bridge (up to 2 H-bridge)Peak & Hold (2 loads)ST L9945八路12V和24V系统全配置高－低边MOSFET预驱动解决方案Operating battery supply voltage 3.8 V to 36 VOperating VDD supply voltage 4.5 V to 5.5 VAll device pins, except the ground pins, withstand at least 40 V Programmable gate charge/discharge currents for improving EMI behavior Individual diagnosis for:Short circuit to batteryOpen loadShort circuit to groundHighly flexible overcurrent sensing implementationPossibility of monitoring external MOS drain to source voltage Possibility of monitoring voltage on external shunt resistor64 programmable overcurrent thresholds independent for each channel Ultra-fast output shutdown in case of overcurrentCurrent limitation for H-Bridge configuration32-bit SPI protocol available for configuration and diagnostics Failures latched even if they occur during diagnostics reading Daisy chain operationSDO protected against overvoltageSafety featuresFast switch off redundant output disable through two external pins Built InSelf Test (BIST) for logic operationHardware Self Check (HWSC) for VDD5 overvoltage comparator Configurable Communication Check (CC) watchdog timer available Disable feedback through bi-directional pinHighly redundant output monitoring through dedicated SPI registers 10-bit ADC for battery and die temperature measurements available through SPI VDD5 monitoring for over/under voltageVPS (battery) monitoring for under voltage图1:L9945框图(1)图2:L9945框图(2)。

1.Product profile1.1General descriptionLogic level N-channel enhancement mode Field-Effect Transistor (FET) in a plastic package using NXP High-Performance Automotive (HPA) TrenchMOS technology. This product has been designed and qualified to the appropriate AEC standard for use in automotive critical applications.1.2Features1.3Applications1.4Quick reference dataBUK9Y40-55BN-channel TrenchMOS logic level FETRev. 03 — 22 February 2008Product data sheet175 °C rated Logic level compatibleQ101 compliant Very low on-state resistance12 V and 24 V loadsAutomotive systemsGeneral purpose power switching Motors, lamps and solenoidsTable 1.Quick referenceSymbol ParameterConditionsMin Typ Max Unit I D drain currentV GS =5V; T mb =25°C; see Figure 1 and 4--26A P tot total power dissipation T mb =25°C; see Figure 2--59W Static characteristicsR DSondrain-source on-state resistanceV GS =5V; I D =15A;T j =25°C; see Figure 12 and 13-3440m ΩAvalanche ruggednessE DS(AL)S non-repetitive drain-source avalanche energy I D =26A; V sup ≤55V;R GS =50Ω; V GS =5V; T j(init)=25°C; unclamped--36mJ2.Pinning information3.Ordering information4.Limiting values[1]Single-pulse avalanche rating limited by maximum junction temperature of 175 °C.[2]Repetitive avalanche rating limited by average junction temperature of 170 °C.[3]Refer to application note AN10273 for further information.Table 2.Pinning Pin Symbol Description Simplified outlineGraphic symbol1S source SOT669 (LFPAK)2S source 3S source 4G gatembDmounting base; connected to drainmb1234Table 3.Ordering informationType numberPackage NameDescriptionVersion BUK9Y40-55BLFPAKplastic single-ended surface-mounted package (LFPAK); 4 leadsSOT669Table 4.Limiting valuesIn accordance with the Absolute Maximum Rating System (IEC 60134).Symbol Parameter ConditionsMin Max Unit V DS drain-source voltage T j ≥25°C; T j ≤175°C -55V V DGR drain-gate voltage R GS =20k Ω-55V V GS gate-source voltage -1515V I D drain current T mb =100°C; V GS =5V; see Figure 1-18A T mb =25°C; V GS =5V; see Figure 1 and 4-26A I DM peak drain current T mb =25°C; t p ≤10μs; pulsed; see Figure 4-106A P tot total power dissipation T mb =25°C; see Figure 2-59W T stg storage temperature -55175°C T jjunction temperature-55175°C Avalanche ruggednessE DS(AL)S non-repetitivedrain-source avalanche energy I D =26A;V sup ≤55V; R GS =50Ω; V GS =5V; T j(init)=25°C; unclamped -36mJE DS(AL)R repetitive drain-sourceavalanche energy see Figure 3[1][2][3]--JSource-drain diode I S source current T mb =25°C-26A I SMpeak source currentt p ≤10μs; pulsed; T mb =25°C-106A5.Thermal characteristicsTable 5.Thermal characteristics Symbol Parameter Conditions Min Typ Max Unit R th(j-mb)thermal resistance from junction to mounting basesee Figure 5--2.5K/W6.CharacteristicsTable 6.CharacteristicsSymbol Parameter Conditions Min Typ Max Unit Static characteristicsV(BR)DSS drain-sourcebreakdown voltage I D=0.25mA;V GS=0V;T j=25°C55--VI D=0.25mA;V GS=0V;T j=-55°C50--VV GS(th)gate-source thresholdvoltage I D=1mA; V DS = V GS;T j=175°C; see Figure110.5--VI D=1mA;V DS = V GS; T j=25°C;see Figure111.1 1.52VI D=1mA; V DS = V GS;T j=-55°C; see Figure11-- 2.3VI DSS drain leakage current V DS=55V;V GS=0V; T j=25°C-0.021μAV DS=55V;V GS=0V;T j=175°C--500μA I GSS gate leakage current V DS=0V; V GS=15V; T j=25°C-2100nAV DS=0V; V GS=-15V;T j=25°C-2100nAR DSon drain-source on-stateresistance V GS=5V;I D=15A;T j=175°C;see Figure12 and 13--84mΩV GS=10V; I D=15A; T j=25°C-3236mΩV GS=4.5V;I D=15A;T j=25°C--45mΩV GS=5V;I D=15A;T j=25°C;see Figure12 and 13-3440mΩSource-drain diodeV SD source-drain voltage I S=20A;V GS=0V; T j=25°C;see Figure16-0.85 1.2Vt rr reverse recovery time I S=20A;dI S/dt=-100A/μs;V GS=-10V;V DS=30V;T j=25°C -45-nsQ r recovered charge-25-nC Dynamic characteristicsQ G(tot)total gate charge I D=15A;V DS=44V;V GS=5V;T j=25°C; see Figure14-11-nCQ GS gate-source charge-2-nC Q GD gate-drain charge-5-nCC iss input capacitance V GS=0V;V DS=25V;f=1MHz; T j=25°C;see Figure15-7651020pFC oss output capacitance-123148pF C rss reverse transfercapacitance-7197pFt d(on)turn-on delay time V DS=30V;R L=2.2Ω;V GS=5V;R G(ext)=10Ω;T j=25°C -17-nst r rise time-93-ns t d(off)turn-off delay time-35-ns t f fall time-72-ns7.Package outlinePlastic single-ended surface-mounted package (LFPAK); 4 leads SOT669Fig 17.Package outline SOT669 (LFPAK)8.Revision historyTable 7.Revision historyDocument ID Release date Data sheet status Change notice Supersedes BUK9Y40-55B_320080222Product data sheet-BUK9Y40-55B_2 Modifications:•The format of this data sheet has been redesigned to comply with the new identityguidelines of NXP Semiconductors.•Legal texts have been adapted to the new company name where appropriate. BUK9Y40-55B_220060411Product data sheet-BUK9Y40_55B-01 BUK9Y40_55B-0120040528Product data sheet--BUK9Y40-55B_3© NXP B.V. 2008. All rights reserved.Product data sheet Rev. 03 — 22 February 2008 11 of 129.Legal information9.1Data sheet status[1]Please consult the most recently issued document before initiating or completing a design. [2]The term ‘short data sheet’ is explained in section “Definitions”.[3]The product status of device(s) described in this document may have changed since this document was published and may differ in case of multiple devices. The latest product status information is available on the Internet at URL .9.2DefinitionsDraft — The document is a draft version only. The content is still under internal review and subject to formal approval, which may result in modifications or additions. NXP Semiconductors does not give any representations or warranties as to the accuracy or completeness ofinformation included herein and shall have no liability for the consequences of use of such information.Short data sheet — A short data sheet is an extract from a full data sheet with the same product type number(s) and title. A short data sheet is intended for quick reference only and should not be relied upon to contain detailed and full information. For detailed and full information see the relevant full data sheet, which is available on request via the local NXP Semiconductors sales office. In case of any inconsistency or conflict with the short data sheet, the full data sheet shall prevail.9.3DisclaimersGeneral — Information in this document is believed to be accurate andreliable. However, NXP Semiconductors does not give any representations or warranties, expressed or implied, as to the accuracy or completeness of such information and shall have no liability for the consequences of use of such information.Right to make changes — NXP Semiconductors reserves the right to make changes to information published in this document, including withoutlimitation specifications and product descriptions, at any time and without notice. This document supersedes and replaces all information supplied prior to the publication hereof.Suitability for use — NXP Semiconductors products are not designed, authorized or warranted to be suitable for use in medical, military, aircraft, space or life support equipment, nor in applications where failure ormalfunction of an NXP Semiconductors product can reasonably be expected to result in personal injury, death or severe property or environmentaldamage. NXP Semiconductors accepts no liability for inclusion and/or use of NXP Semiconductors products in such equipment or applications and therefore such inclusion and/or use is at the customer’s own risk.Applications — Applications that are described herein for any of these products are for illustrative purposes only. NXP Semiconductors makes no representation or warranty that such applications will be suitable for the specified use without further testing or modification.Quick reference data — The Quick reference data is an extract of theproduct data given in the Limiting values and Characteristics sections of this document, and as such is not complete, exhaustive or legally binding.Limiting values — Stress above one or more limiting values (as defined in the Absolute Maximum Ratings System of IEC 60134) may cause permanent damage to the device. Limiting values are stress ratings only and operation of the device at these or any other conditions above those given in theCharacteristics sections of this document is not implied. Exposure to limiting values for extended periods may affect device reliability.Terms and conditions of sale — NXP Semiconductors products are sold subject to the general terms and conditions of commercial sale, as published at /profile/terms , including those pertaining to warranty, intellectual property rights infringement and limitation of liability, unlessexplicitly otherwise agreed to in writing by NXP Semiconductors. In case of any inconsistency or conflict between information in this document and such terms and conditions, the latter will prevail.No offer to sell or license — Nothing in this document may be interpreted or construed as an offer to sell products that is open for acceptance or the grant, conveyance or implication of any license under any copyrights, patents or other industrial or intellectual property rights.9.4TrademarksNotice: All referenced brands, product names, service names and trademarks are the property of their respective owners.TrenchMOS — is a trademark of NXP B.V.10.Contact informationFor additional information, please visit: For sales office addresses, send an email to: salesaddresses@Document status [1][2]Product status [3]DefinitionObjective [short] data sheet Development This document contains data from the objective specification for product development. Preliminary [short] data sheet Qualification This document contains data from the preliminary specification. Product [short] data sheetProductionThis document contains the product specification.11.Contents1Product profile. . . . . . . . . . . . . . . . . . . . . . . . . . 11.1General description . . . . . . . . . . . . . . . . . . . . . 11.2Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.3Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.4Quick reference data . . . . . . . . . . . . . . . . . . . . 12Pinning information. . . . . . . . . . . . . . . . . . . . . . 23Ordering information. . . . . . . . . . . . . . . . . . . . . 24Limiting values. . . . . . . . . . . . . . . . . . . . . . . . . . 25Thermal characteristics . . . . . . . . . . . . . . . . . . 46Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . 57Package outline. . . . . . . . . . . . . . . . . . . . . . . . . 98Revision history. . . . . . . . . . . . . . . . . . . . . . . . 109Legal information. . . . . . . . . . . . . . . . . . . . . . . 119.1Data sheet status . . . . . . . . . . . . . . . . . . . . . . 119.2Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . 119.3Disclaimers. . . . . . . . . . . . . . . . . . . . . . . . . . . 119.4Trademarks. . . . . . . . . . . . . . . . . . . . . . . . . . . 1110Contact information. . . . . . . . . . . . . . . . . . . . . 1111Contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12Please be aware that important notices concerning this document and the product(s)described herein, have been included in section ‘Legal information’.© NXP B.V.2008.All rights reserved.For more information, please visit: For sales office addresses, please send an email to: salesaddresses@Date of release: 22 February 2008Document identifier: BUK9Y40-55B_3。

ANPEC reserves the right to make changes to improve reliability or manufacturability without notice, and advise customers to obtain the latest version of relevant information to verify before placing orders.APM4435KFeaturesApplications• Power Management in Notebook Computer,Portable Equipment and Battery Powered SystemsPin DescriptionOrdering and Marking InformationP-Channel MOSFETAPM4435Handling Code Temp. Range Package CodePackage Code K : SOP-8Operating Junction Temp. Range C : -55 to 150C Handling CodeTR : Tape & Reel Lead Free CodeL : Lead Free Device Blank : Original Device APM4435 K :XXXXX - Date CodeLead Free Code APM4435XXXXX• -30V/-8A ,RDS(ON)=16m Ω(typ.) @ VGS =-10VRDS(ON)=24m Ω(typ.) @ V GS =-4.5V• Super High Dense Cell Design • Reliable and Rugged • SOP-8 Package•Lead Free Available (RoHS Compliant)Top View of SOP − 8G(4)(1, 2, 3)(5, 6, 7, 8)Note: ANPEC lead-free products contain molding compounds/die attach materials and 100% matte in plate termina-tion finish; which are fully compliant with RoHS and compatible with both SnPb and lead-free soldiering operations.ANPEC lead-free products meet or exceed the lead-free requirements of IPC/JEDEC J STD-020C for MSL classifica-tion at lead-free peak reflow temperature.APM4435KAbsolute Maximum Ratings (TA= 25°C unless otherwise noted)Electrical Characteristics (TA = 25°C unless otherwise noted)*Surface Mounted on 1in2 pad area, t ≤ 10sec.APM4435KElectrical Characteristics (Cont.) (T= 25°C unless otherwise noted)Aa : Pulse test ; pulse width≤300µs, duty cycle≤2%.b : Guaranteed by design, not subject to production testing.APM4435K1E-41E-30.010.1110301E-30.010.112Typical Characteristics-I D - D r a i n C u r r e n t (A )Drain CurrentT j - Junction Temperature (°C)Safe Operation Area-V DS - Drain - Source Voltage (V)Thermal Transient ImpedanceSquare Wave Pulse Duration (sec)Power DissipationP t o t - P o w e r (W )T j - Junction Temperature (°C)-I D - D r a i n C u r r e n t (A )204060801001201401600.00.51.01.52.02.5204060801001201401602468100.010.11101000.010.1110100N o r m a l i z e d T r a n s i en t T h e r m a l R e s i s t a n c e012345-50-250255075100125150 -V GS - Gate - Source Voltage (V)T j - Junction Temperature (°C)APM4435K-V DS - Drain - Source Voltage (V)Drain-Source On ResistanceN o r m a l i z e dO n R e s i s t a n c e T j - Junction Temperature (°C)C - C a p a c i t a n c e (p F )-V SD - Source - Drain Voltage (V)-I S - S o u r c e C u r r e n t (A )CapacitanceGate ChargeQ G - Gate Charge (nC)-V G S - G a t e -s o u r c e V o l t a g e (V )Typical Characteristics (Cont.)-50-252550751001251500.000.250.500.751.001.251.501.752.000.1110305101520253005001000150020002500300035004000450050005101520253035404550APM4435KPackaging InformationSOP-8 pin ( Reference JEDEC Registration MS-012)APM4435KT LT P25T e m p e r a t u r eTimeReflow Condition (IR/Convection or VPR Reflow)Classification Reflow ProfilesPhysical SpecificationsAPM4435KCarrier Tape & Reel DimensionsReliability Test ProgramClassification Reflow Profiles(Cont.)APM4435KCover Tape DimensionsCarrier Tape & Reel Dimensions(Cont.)(mm)Customer ServiceAnpec Electronics Corp.Head Office :No.6, Dusing 1st Road, SBIP,Hsin-Chu, Taiwan, R.O.C.Tel : 886-3-5642000Fax : 886-3-5642050Taipei Branch :7F, No. 137, Lane 235, Pac Chiao Rd.,Hsin Tien City, Taipei Hsien, Taiwan, R. O. C.Tel : 886-2-89191368Fax : 886-2-89191369。

General DescriptionThe MAX9945 operational amplifier features an excellent combination of low operating power and low input volt-age noise. In addition, MOS inputs enable the MAX9945to feature low input bias currents and low input current noise. The device accepts a wide supply voltage range from 4.75V to 38V and draws a low 400µA quiescent cur-rent. The MAX9945 is unity-gain stable and is capable of rail-to-rail output voltage swing.The MAX9945 is ideal for portable medical and industri-al applications that require low noise analog front-ends for performance applications such as photodiode trans-impedance and chemical sensor interface circuits.The MAX9945 is available in both an 8-pin µMAX ®and a space-saving, 6-pin TDFN package, and is specified over the automotive operating temperature range (-40°C to +125°C).ApplicationsMedical Pulse Oximetry Photodiode Sensor InterfaceIndustrial Sensors and Instrumentation Chemical Sensor Interface High-Performance Audio Line Out Active Filters and Signal ProcessingFeatureso +4.75V to +38V Single-Supply Voltage Range o ±2.4V to ±19V Dual-Supply Voltage Range o Rail-to-Rail Output Voltage Swing o 400µA Low Quiescent Current o 50fA Low Input Bias Current o 1fA/√Hz Low Input Current Noise o 15nV/√Hz Low Noise o 3MHz Unity-Gain Bandwidtho Wide Temperature Range from -40°C to +125°C o Available in Space-Saving, 6-Pin TDFN Package (3mm x 3mm)MAX994538V , Low-Noise, MOS-Input,Low-Power Op Amp________________________________________________________________Maxim Integrated Products 119-4398; Rev 1; 12/10For pricing, delivery, and ordering information,please contact Maxim Direct at 1-888-629-4642,or visit Maxim’s website at .Ordering Information*EP = Exposed pad.µMAX is a registered trademark of Maxim Integrated Products, Inc.Typical Operating CircuitM A X 994538V , Low-Noise, MOS-Input,Low-Power Op AmpABSOLUTE 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 (V CC to V EE )..................................-0.3V to +40V IN+, IN-, OUT Voltage......................(V EE - 0.3V) to (V CC + 0.3V)IN+ to IN-.............................................................................±12V OUT Short Circuit to Ground Duration....................................10s Continuous Input Current into Any Pin.............................±20mA Continuous Power Dissipation (T A = +70°C)6-Pin TDFN-EP (derate 23.8mW/°C above +70°C)Multilayer Board....................................................1904.8mW8-Pin µMAX (derate 4.8mW/°C above +70°C)Multilayer Board......................................................387.8mW Operating Temperature Range .........................-40°C to +125°C Junction Temperature......................................................+150°C Storage Temperature Range.............................-65°C to +150°C Lead Temperature (soldering, 10s).................................+300°C Soldering Temperature....................................................+260°CNote 1:Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board. For detailed information on package thermal considerations, refer to /thermal-tutorial .PACKAGE THERMAL CHARACTERISTICS (Note 1)TDFN-EPJunction-to-Ambient Thermal Resistance (θJA )............42°C/W Junction-to-Case Thermal Resistance (θJC )...................9°C/WµMAXJunction-to-Ambient Thermal Resistance (θJA ).......206.3°C/W Junction-to-Case Thermal Resistance θJC ...................42°C/WMAX994538V , Low-Noise, MOS-Input,Low-Power Op Amp_______________________________________________________________________________________3ELECTRICAL CHARACTERISTICS (continued)(V CC = +15V, V EE = -15V, V IN+= V IN-= V GND = 0V, R OUT = 100k Ωto GND, T A = -40°C to +125°C, typical values are at T A = +25°C,unless otherwise noted.) (Note 2)Note 3:Guaranteed by design. IN+ and IN- are internally connected to the gates of CMOS transistors. CMOS GATE leakage is sosmall that it is impractical to test in production. Devices are screened during production testing to eliminate defective units.Note 4:Specified over all temperatures and process variation by circuit simulation.M A X 994538V , Low-Noise, MOS-Input,Low-Power Op Amp 4_______________________________________________________________________________________Typical Operating Characteristics(V CC = +15V, V EE = -15V, V IN+= V IN-= V GND = 0V, R OUT = 100k Ωto GND, T A = -40°C to +125°C, typical values are at T A = +25°C,unless otherwise noted.)QUIESCENT SUPPLY CURRENTvs. SUPPLY VOLTAGE AND TEMPERATURESUPPLY VOLTAGE (V)S U P P L Y C U R R E N T (µA )3530252015103004005006002005OUTPUT VOLTAGE SWING LOWvs. TEMPERATURETEMPERATURE (°C)V O L - V E E (V )10012080604020-200.100.050.150.200.250-40OUTPUT VOLTAGE SWING HIGHvs. TEMPERATURETEMPERATURE (°C)V C C - V O H (V )10012080604020-200.100.050.150.200.250-40INPUT BIAS CURRENT vs. TEMPERATUREM A X 9945 t o c 04TEMPERATURE (°C)I B I A S (p A )10080602040-2001020304050607080-10-40120INPUT VOLTAGE 0.1Hz TO 10Hz NOISEMAX9945 toc051s/div 1µV/divINPUT VOLTAGE-NOISE DENSITYvs. FREQUENCYFREQUENCY (Hz)I N P U T V O L T A G E -N O I S E D E N S I T Y (n V H z )10,000100,0001000100101001000101TOTAL HARMONIC DISTORTIONvs. FREQUENCYFREQUENCY (Hz)T H D (d B )100,00010,0001000-90-70-80-110-100100TOTAL HARMONIC DISTORTION + NOISEvs. FREQUENCYFREQUENCY (Hz)T H D +N (d B )-90-80-70-60-50-100100,00010,000100100010INPUT OFFSET VOLTAGE vs. COMMON-MODE VOLTAGECOMMON-MODE VOLTAGE (V)I N P U T O F F S E T V O L T A G E (μV )105-10-510008000600400200-15MAX994538V , Low-Noise, MOS-Input,Low-Power Op Amp_______________________________________________________________________________________5INPUT OFFSET VOLTAGE vs. TEMPERATURETEMPERATURE (°C)I N P U T O F F S E T V O L T A G E (µV )100120804060-202010008000600400200-40OPEN-LOOP GAIN vs. FREQUENCYFREQUENCY (Hz)O P E N -L O O P G A I N (d B )12080-40401m1101001k10k 100k 1M 10MCOMMON-MODE REJECTION RATIOvs. FREQUENCYM A X 9945 t o c 12FREQUENCY (Hz)C M R R (d B )1M100k1001k10k-90-80-70-60-50-40-30-20-1001010MPOWER-SUPPLY REJECTION RATIOvs. FREQUENCYFREQUENCY (Hz)P S R R (d B )1M100k10k1k10010-100-80-60-40-200-120110MRESISTOR ISOLATION vs. CAPACITIVE LOADR ISO (Ω)C L O AD (p F )10010100010,0001001Typical Operating Characteristics (continued)(V CC = +15V, V EE = -15V, V IN+= V IN-= V GND = 0V, R OUT = 100k Ωto GND, T A = -40°C to +125°C, typical values are at T A = +25°C,unless otherwise noted.)M A X 994538V , Low-Noise, MOS-Input,Low-Power Op Amp 6_______________________________________________________________________________________Typical Operating Characteristics (continued)(V CC = +15V, V EE = -15V, V IN+= V IN-= V GND = 0V, R OUT = 100k Ωto GND, T A = -40°C to +125°C, typical values are at T A = +25°C,unless otherwise noted.)LARGE SIGNAL-STEP RESPONSE1μs/div +1V-1V V OUT 500mV/div SMALL SIGNAL-STEP RESPONSE2μs/div+20mV-20mVV OUT 10mV/divA V = 1V/V V IN = 40mV P-P R L = 100k ΩLARGE-SIGNAL RESPONSEvs. FREQUENCYFREQUENCY (kHz)O U T P U T V O L T A G E (V P -P )10,0001000100105101525203001LARGE SIGNAL-STEP RESPONSE4μs/div+5V-5VV OUT 2.5V/divOUTPUT IMPEDANCE vs. FREQUENCYFREQUENCY (Hz)O U T P U T I M P E D A N C E (Ω)1M100k10k1k1000.101.0010.00100.001000.000.011010MOP-AMP STABILITYvs. CAPACITIVE AND RESISTIVE LOADSPARALLEL LOAD RESISTANCE (k Ω)P A R A L L E L L O A D C A P A C I T A N C E (p F )10,0001001000100010010,0001010Detailed Description The MAX9945 features a combination of low input cur-rent and voltage noise, rail-to-rail output voltage swing, wide supply voltage range, and low-power operation. The MOS inputs on the MAX9945 make it ideal for use as transimpedance amplifiers and high-impedance sensor interface front-ends in medical and industrial applications. The MAX9945 can interface with small signals from either current-sources or high-output impedance voltage sources. Applications include pho-todiode pulse oximeters, pH sensors, capacitive pres-sure sensors, chemical analysis equipment, smoke detectors, and humidity sensors.A high 130dB open-loop gain (typ) and a wide supply voltage range, allow high signal-gain implementations prior to signal conditioning circuitry. Low quiescent supply current makes the MAX9945 compatible with portable systems and applications that operate under tight power budgets. The combination of excellent THD, low voltage noise, and MOS inputs also make the MAX9945 ideal for use in high-performance active fil-ters for data acquisition systems and audio equipment.Low-Current, Low-Noise Input Stage The MAX9945 features a MOS-input stage with only 50fA (typ) of input bias current and a low 1fA/√Hz(typ) input current-noise density. The low-frequency input voltage noise is a low 2µV P-P(typ). The input stage accepts a wide common-mode range, extending from the negative supply, V EE,to within 1.2V of the positive supply, V CC.The MAX9945 output stage swings to within 50mV (typ)of either power-supply rail with a 100kΩload and pro-vides a 3MHz GBW with a 2.2V/µs slew rate. The device is unity-gain stable, and unlike other deviceswith a low quiescent current, can drive a 120pF capaci-tive load without compromising stability.Applications InformationHigh-Impedance Sensor Front EndsHigh-impedance sensors can output signals of interestin either current or voltage form. The MAX9945 inter-faces to both current-output sensors such as photo-diodes and potentiostat sensors, and high-impedance voltage sources such as pH sensors.For current-output sensors, a transimpedance amplifieris the most noise-efficient method for converting theinput signal to a voltage. High-value feedback resistorsare commonly chosen to create large gains, while feed-back capacitors help stabilize the amplifier by cancel-ing any zeros in the transfer function created by ahighly capacitive sensor or cabling. A combination oflow-current noise and low-voltage noise is important forthese applications. Take care to calibrate out photodi-ode dark current if DC accuracy is important. The high bandwidth and slew rate also allows AC signal pro-cessing in certain medical photodiode sensor applica-tions such as pulse oximetry.MAX994538V, Low-Noise, MOS-Input,Low-Power Op Amp _______________________________________________________________________________________7Pin DescriptionM A X 9945F or voltage-output sensors, a noninverting amplifier is typically used to buffer and/or apply a small gain to, the input voltage signal. Due to the extremely high imped-ance of the sensor output, a low input bias current with a small temperature variation is very important for these applications.Power-Supply DecouplingThe MAX9945 operates from a +4.75V to +38V, V EE ref-erenced power supply. Bypass the power-supply inputs V CC and V EE to a quiet copper ground plane,with a 0.1µF ceramic capacitor in parallel with a 4.7µF electrolytic capacitor, placed close to the leads.Layout TechniquesA good layout is critical to obtaining high performance especially when interfacing with high-impedance sen-sors. Use shielding techniques to guard against para-sitic leakage paths. F or transimpedance applications,for example, surround the inverting input, and the traces connecting to it, with a buffered version of its own voltage. A convenient source of this voltage is the noninverting input pin. Pins 1, 5, and 8 on the µMAX package are unconnected, and can be connected to an analog common potential, or to the driven guard potential, to reduce leakage on the inverting input.A good layout guard rail isolates sensitive nodes, such as the inverting input of the MAX9945 and the traces connecting to it (see Figure 1), from varying or large volt-age differentials that otherwise occur in the rest of the circuit board. This reduces leakage and noise effects,allowing sensitive measurements to be made accurately.Take care to also decrease the amount of stray capaci-tance at the op amp’s inputs to improve stability. To achieve this, minimize trace lengths and resistor leads by placing external components as close as possible to the package. If the sensor is inherently capacitive, or is connected to the amplifier through a long cable, use a low-value feedback capacitor to control high-frequency gain and peaking to stabilize the feedback loop.38V , Low-Noise, MOS-Input,Low-Power Op Amp 8_______________________________________________________________________________________Figure 1. Shielding the Inverting Input to Reduce LeakageFigure 2. Input Differential Voltage ProtectionInput Differential Voltage ProtectionDuring normal op-amp operation, the inverting and non-inverting inputs of the MAX9945 are at approximately the same voltage. The ±12V absolute maximum input differential voltage rating offers sufficient protection for most applications. If there is a possibility of exceeding the input differential voltage specification, in the pres-ence of extremely fast input voltage transients or due to certain application-specific fault conditions, use exter-nal low-leakage pico-amp diodes and series resistors to protect the input stage of the amplifier (see Figure 2).The extremely low input bias current of the MAX9945allows a wide range of input series resistors to be used.If low input voltage noise is critical to the application,size the input series resistors appropriately.MAX994538V , Low-Noise, MOS-Input,Low-Power Op Amp_______________________________________________________________________________________9Chip InformationPROCESS: BiCMOSM A X 994538V , Low-Noise, MOS-Input,Low-Power Op Amp 10______________________________________________________________________________________Pin ConfigurationsMAX994538V , Low-Noise, MOS-Input,Low-Power Op AmpPackage InformationFor the latest package outline information and land patterns, go to /packages . Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status.M A X 994538V , Low-Noise, MOS-Input,Low-Power Op Amp 12______________________________________________________________________________________MAX994538V , Low-Noise, MOS-Input,Low-Power Op Amp______________________________________________________________________________________13Package Information (continued)For the latest package outline information and land patterns, go to /packages . Note that a "+", "#", or "-" in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status.M A X 994538V , Low-Noise, MOS-Input,Low-Power Op Amp Maxim cannot assume r esponsibility for use of any cir cuitr y other than cir cuitr y entir ely embodied in a Maxim pr oduct. No cir cuit patent licenses ar e 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©2010 Maxim Integrated ProductsMaxim is a registered trademark of Maxim Integrated Products, Inc.。