MAX44284-310858

GeneralDescriptionTheMAX44284isahigh-side,current-senseamplifierthatoperateswitha1.7Vto5.5Vsinglesupplyandisoptimizedforverylowpoweroperationwithonly21µAofquiescentcurrent.TheMAX44284offersprecisionaccuracyspecificationsof2μVVOSandgainerrorof0.05%.Thedevicefeaturesaninputcommon-modevoltagerangefrom-0.1Vto+36V.Thiscurrent-senseamplifierhasavoltageoutputandisofferedinfourdifferentgainversions.TheMAX44284isofferedinsmall6-bump,0.4mm-pitchWLP(1.3mmx0.9mm)and6-pinSOT23packagesandisspecifiedforoperationoverthe-40°Cto+125°Cautomotivetemperaturerange.Applications●SmartphonesandTablets●NotebookComputers●DC-DCCurrentSensinginPowerManagement●Portable-/Battery-PoweredSystems●MedicalPulseOximetersandInfusionPumps●Base-StationsBenefitsandFeatures●SupportsUseofSmallCurrent-SenseResistorstoImprovePower-SupplyConversionEfficiencyandMeasurementAccuracy•InputBiasCurrentof80nA(max)•VeryLow2μVInputOffsetVoltage(MAX44284F/H)•ExtremelyLow50nV/°CInputOffsetTempcoCoefficient•-0.1Vto+36VWideInputCommon-ModeRange•Low0.05%GainError●ExtendsBatteryLife•LowSupplyCurrentof21μA•1.7Vto5.5VSingleSupply•ShutdownInput(IndependentofVDD)●FourFixedGainOptionsSimplifyDesign•50V/V–MAX44284F•100V/V–MAX44284H•200V/V–MAX44284W•500V/V–MAX44284EOrderingInformationappearsatendofdatasheet.MAX4428436V,InputCommon-Mode,High-Precision,Low-PowerCurrent-SenseAmplifier19-6862;Rev8;8/18Clickhereforproductionstatusofspecificpartnumbers.TypicalApplicationCircuitRSENSEVBATT=UPTO36VRS+RS-ADCµCVDD=3.3VOUTVDD=3.3VLOADMAX44284ILOADVDDtoGND............................................................-0.3Vto+6VRS+,RS-toGND..................................................-0.3Vto+40VRS+toRS-..........................................................................±40VOUT,SHDNtoGND.................................-0.3Vto(VDD+0.3V)ContinuousInputCurrent(anypin)..................................±20mAContinuousPowerDissipation(TA=+70°C)WLP(derate10.5mW/°Cabove+70°C)......................840mWSOT23(derate4.3mW/°Cabove+70°C).................347.8mWOperatingTemperatureRange.........................-40°Cto+125°CJunctionTemperature......................................................+150°CStorageTemperatureRange............................-65°Cto+150°CLeadTemperature(soldering,10s).................................+300°CSolderingTemperature(reflow).......................................+260°CPACKAGECODEU6+1,U6+1AOutlineNumber21-0058LandPatternNumber90-0175ThermalResistance,Single-LayerBoard:JunctiontoAmbient-θJA(C/W)N/AJunctiontoCase-θJC(C/W)80ThermalResistance,Multi-LayerBoardJunctiontoAmbient(θJA)(C/W)115JunctiontoCase(θJC)(C/W)806SOT23PACKAGECODEW60A1+1OutlineNumber21-0656LandPatternNumberRefertoApplicationNote1891ThermalResistance,Multi-LayerBoardJunctiontoAmbient(θJA)(C/W)95.15JunctiontoCase(θJC)(C/W)N/A6WLPMAX4428436V,InputCommon-Mode,High-Precision,Low-PowerCurrent-SenseAmplifierwww.maximintegrated.comMaximIntegrated│2AbsoluteMaximumRatingsStressesbeyondthoselistedunder“AbsoluteMaximumRatings”maycausepermanentdamagetothedevice.Thesearestressratingsonly,andfunctionaloperationofthedeviceattheseoranyotherconditionsbeyondthoseindicatedintheoperationalsectionsofthespecificationsisnotimplied.Exposuretoabsolutemaximumratingconditionsforextendedperiodsmayaffectdevicereliability.PackageInformationPackagethermalresistanceswereobtainedusingthemethoddescribedinJEDECspecificationJESD51-7,usingafour-layerboard.Fordetailedinformationonpackagethermalconsiderations,refertowww.maximintegrated.com/thermal-tutorial.Forthelatestpackageoutlineinformationandlandpatterns(footprints),gotowww.maximintegrated.com/packages.Notethata“+”,“#”,or“-”inthepackagecodeindicatesRoHSstatusonly.Packagedrawingsmayshowadifferentsuffixcharacter,butthedrawingpertainstothepackageregardlessofRoHSstatus.(VDD=3.3V,VCM=12V,VSENSE=VFS/2,VFS=(VDD-VOH-VOL)/Gain,VSHDN=VDD,RL=10kΩtoGND,TA=-40°Cto+125°C,unlessotherwisenoted.TypicalvaluesareatTA=+25°C.)(Note2)PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITSPOWERSUPPLYSupplyVoltageVDDGuaranteedbyPSRR1.75.5VShutdownSupplyCurrentISHDN0.30.8μASupplyCurrentIDDTA=+25°C,RL=∞2131.2μA-40°C≤TA≤+125°C,RL=∞41.5Power-SupplyRejectionRatioPSRR1.7V≤VDD≤5.5V,VOUT=1V100110dBShutdownVoltageLowVIL0.55VShutdownVoltageHighVIH1.3VDCCHARACTERISTICSInputCommon-ModeVoltageRangeVCMGuaranteedbyCMRR-0.1+36VCommon-ModeRejectionRatio(Note5)CMRR-0.1V≤VCM≤+36V,VCM=RS-91.3140dB+0.1V≤VCM≤+36V,VCM=RS-(Note7)120145InputBiasCurrentIRS+,IRS-280nAInputOffsetCurrentIOS250nAInputOffsetVoltage(Note3)VOSMAX44284F(TA=+25°C)±2±10μVMAX44284F(-40°C≤TA≤+125°C)±28MAX44284H(TA=+25°C)±2±12MAX44284H(-40°C≤TA≤+125°C)±28MAX44284W(TA=+25°C)±10±20.5MAX44284W(-40°C≤TA≤+125°C)±38MAX44284E(TA=+25°C)±15±26MAX44284E(-40°C≤TA≤+125°C)±40InputOffsetVoltageTemperatureDriftTCVOS50nV°CGainGMAX44284F50V/VMAX44284H100MAX44284W200MAX44284E500MAX4428436V,InputCommon-Mode,High-Precision,Low-PowerCurrent-SenseAmplifierwww.maximintegrated.comMaximIntegrated│3ElectricalCharacteristics(VDD=3.3V,VCM=12V,VSENSE=VFS/2,VFS=(VDD-VOH-VOL)/Gain,VSHDN=VDD,RL=10kΩtoGND,TA=-40°Cto+125°C,unlessotherwisenoted.TypicalvaluesareatTA=+25°C.)(Note2)PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITSGainError(Note4)GEMAX44284F(TA=+25°C)0.050.15%MAX44284F(-40°C≤TA≤+125°C)0.20MAX44284H(TA=+25°C)0.050.15MAX44284H(-40°C≤TA≤+125°C)0.26MAX44284W(TA=+25°C)0.050.15MAX44284W(-40°C≤TA≤+125°C)0.35MAX44284E(TA=+25°C)0.050.16MAX44284E(-40°C≤TA≤+125°C)0.39OutputVoltageHighVOHVOH=VDD-VOUT,RL=10kWtoGND2535mVISOURCE=100μA20OutputVoltageLowVOLNoload0.31mVISINK=100µA20InputDifferentialImpedance6MWOutputImpedance200mWACCHARACTERISTICSSmall-SignalBandwidthBW3dBMAX44284F3kHzMAX44284H1.8MAX44284W1MAX44284E0.4InputVoltage-NoiseDensityenf=1kHz150nV/√HzACCommon-ModeRejectionRatioACCMRRf=10kHz,600mVP-Psinusoidalwaveform80dBMAX4428436V,InputCommon-Mode,High-Precision,Low-PowerCurrent-SenseAmplifierwww.maximintegrated.comMaximIntegrated│4ElectricalCharacteristics(continued)(VDD=3.3V,VCM=12V,VSENSE=VFS/2,VFS=(VDD-VOH-VOL)/Gain,VSHDN=VDD,RL=10kΩtoGND,TA=-40°Cto+125°C,unlessotherwisenoted.TypicalvaluesareatTA=+25°C.)(Note2)Note2:Alldevicesare100%productiontestedatTA=+25°C.Alltemperaturelimitsareguaranteedbydesign.Note3:VOSiscalculatedbyapplyingtwovaluesofVSENSE(10%offull-scalerangeto90%offull-scalerange).Note4:GainErroriscalculatedbyapplyingtwovaluesofVSENSE(10%offull-scalerangeto90%offull-scalerange)andcalculat-ingtheerroroftheslope,vs.theideal.Note5:CMRRmeasurementisdoneatVOUT=VDD/2condition.Note6:PSRRmeasurementisdoneatVOUT=1Vcondition.Note7:Parameterisguaranteedbydesign.PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITSSettlingTimetSVOUTfrom250mVto2.5V,Gain=50,within12-bitaccuracy1500µsVOUTfrom250mVto2.5V,Gain=100,within12-bitaccuracy1500VOUTfrom250mVto2.5V,Gain=200,within12-bitaccuracy1800VOUTfrom250mVto2.5V,Gain=500,within12-bitaccuracy4000CapacitiveLoadCLRISO=0W500pFRISO=20W2200MAX4428436V,InputCommon-Mode,High-Precision,Low-PowerCurrent-SenseAmplifierwww.maximintegrated.comMaximIntegrated│5ElectricalCharacteristics(continued)(TA=+25°C,unlessotherwisenoted.)MAX4428436V,InputCommon-Mode,High-Precision,Low-PowerCurrent-SenseAmplifierMaximIntegrated│6www.maximintegrated.comTypicalOperatingCharacteristics17192123252729-50-250255075100125SUPPLYCURRENT(µA)TEMPERATURE(°C)SUPPLYCURRENTvs.TEMPERATUREtoc01aVDD=5.5VVDD=1.7VVDD=3.3VGAIN=50V/V2022242628303234-50-250255075100125SUPPLYCURRENT(µA)TEMPERATURE(°C)SUPPLYCURRENTvs.TEMPERATUREtoc01bVDD=5.5VVDD=1.7VVDD=3.3VGAIN=100V/V171819202122232425-50-250255075100125SUPPLYCURRENT(µA)TEMPERATURE(°C)SUPPLYCURRENTvs.TEMPERATUREtoc01cVDD=5.5VVDD=1.7VVDD=3.3VGAIN=200V/V2223242526272829303132-50-250255075100125SUPPLYCURRENT(µA)TEMPERATURE(°C)SUPPLYCURRENTvs.TEMPERATUREtoc01dVDD=5.5VVDD=1.7VVDD=3.3VGAIN=500V/V024681012141618-0.08-0.06-0.04-0.0200.020.040.060.08OCCURRENCEN(%)GAINERROR(%)GAINERRORHISTOGRAMtoc03HISTOGRAMALLGAINOPTIONSSUPPLYCURRENTvs.COMMONVOLTAGEVCM(V)SUPPLYCURRENT(µA)2122232425262728293020-1491419242934VDD=3.3VMAX44284toc02TA=-40ºCTA=+125ºCTA=+85ºCTA=+25ºC051015202530-6-4-20246OCCURRENCEN(%)INPUTOFFSETVOLTAGE(μV)INPUTOFFSETVOLTAGEHISTOGRAMtoc04aHISTOGRAMGAIN=50V/VGAIN=100V/V0246810121416-20-18-16-14-12-10-8-6-4-202468101214161820OCCURRENCEN(%)INPUTOFFSETVOLTAGE(μV)INPUTOFFSETVOLTAGEHISTOGRAMtoc04bHISTOGRAMGAIN=200V/V(TA=+25°C,unlessotherwisenoted.)VOHvs.IOUTMAX44284toc07IOUT(mA)VOH(mV)9867234511002003004005006007008009000010VDD=3.3VMAX4428436V,InputCommon-Mode,High-Precision,Low-PowerCurrent-SenseAmplifierMaximIntegrated│7www.maximintegrated.comTypicalOperatingCharacteristics(continued)012345678-60-50-40-30-20-100102030405060OCCURRENCEN(%)INPUTOFFSETVOLTAGEDRIFT(nV/°C)INPUTOFFSETVOLTAGEDRIFTHISTOGRAMtoc05HISTOGRAMALLGAINOPTIONSSHUTDOWNSUPPLYCURRENTvs.TEMPERATUREMAX44284toc06SUPPLYCURRENT(µA)0.10.20.30.40.50.60.70TEMPERATURE(°C)120100806040200-20-40GAIN=50V/VVDD=5.5VVDD=3.3VVDD=1.7VVOLvs.ISINKMAX44284toc08ISINK(mA)8642010VOL(mV)10020030040050060070080090010000VDD=3.3V051015202530-50-250255075100125INPUTOFFSETVOLTAGE(µV)TEMPERATURE(°C)INPUTOFFSETVOLTAGEvs.TEMPERATUREtoc09GAIN=200GAIN=100V/VGAIN=50VVGAIN=50V/VGAINERRORvs.INPUTCOMMON-MODEVOLTAGEMAX44284toc10VCM(V)GAINERROR(%)34.929.924.919.914.99.94.90.010.020.030.040.050-0.1(TA=+25°C,unlessotherwisenoted.)MAX4428436V,InputCommon-Mode,High-Precision,Low-PowerCurrent-SenseAmplifierMaximIntegrated│8www.maximintegrated.comTypicalOperatingCharacteristics(continued)GAINERRORvs.SUPPLYVOLTAGEMAX44284toc11VDD(V)GAINERROR(%)5.14.74.04.42.52.83.23.62.10.0050.0100.0150.0200.0250.0300.0350.0400.0450.05001.75.5-0.04-0.0200.020.040.060.08-50-250255075100125GAINERROR(%)TEMPERATURE(°C)GAINERRORvs.TEMPERATUREtoc12GAIN=100V/VGAIN=200V/VGAIN=500V/VGAIN=50V/VCOMMON-MODEREJECTIONRATIOvs.TEMPERATUREMAX44284toc13TEMPERATURE(ºC)CMRR(dB)1007525500-259010011012013014015016017018080-50125VCM=0to36VVCM=-0.1Vto+36VPOWER-SUPPLYREJECTIONRATIOvs.TEMPERATUREMAX44284toc14TEMPERATURE(ºC)PSRR(dB)1007525500-25809010011012013014015070-50125-4-2024681012-40-25-105203550658095110125INPUTBIASCURRENT(nA)TEMPERATURE(°C)INPUTBIASCURRENTvs.TEMPERATUREtoc16VCM=12VFORALLGAINOPTIONS-1200-1000-800-600-400-2000200-13711151923273135INPUTBIASCURRENT(nA)INPUTCOMMON-MODEVOLTAGE(V)INPUTBIASCURRENTvs.INPUTCOMMON-MODEVOLTAGEtoc15TA=+25°CTA=+85°CTA=-40°CTA=+125°CFORALLGAINOPTIONS(TA=+25°C,unlessotherwisenoted.)MAX4428436V,InputCommon-Mode,High-Precision,Low-PowerCurrent-SenseAmplifierMaximIntegrated│9www.maximintegrated.comTypicalOperatingCharacteristics(continued)INPUT-VOLTAGENOISEvs.FREQUENCYMAX44284toc18FREQUENCY(Hz)INPUTVOLTAGENOISE(nV√Hz)10k1k10010110100100000.1100kSMALL-SIGNALINPUTSTEPRESPONSE(VDD=3.3V,RL=Open,G=100V/V)MAX44284toc20600mV300mVVOUT6mV3mVVIN400µs/div0.1HzTO10HzPEAK-TO-PEAKNOISEMAX44284toc19VOUT1µV/div1s/divGAINvs.FREQUENCYMAX44284toc17FREQUENCY(Hz)MAGNITUDE(dB)10k1k100-1001020304050607080-2010100kG=100V/VG=50V/VG=200V/VG=500V/V0.010.1110100100010000100100010000100000RISO(Ω)CAPACITIVELOAD(pF)STABILITYvs.CAPACITIVEANDRISOINSERIESWITHCLOADSTABLEUNSTABLEtoc22LARGE-SIGNALINPUTSTEPRESPONSE(VCC=3.3V,RL=Open)MAX44284toc210.3VVOUT30mV3mV3VVIN400µs/divPINBUMPNAMEFUNCTIONSOT23WLP1A2VDDPower-SupplyVoltageInput.BypassVDDtoGNDwith0.1μFand4.7μFcapacitorsinparallelascloseaspossibletothedevice.2B2GNDGround3A1RS+ExternalSenseResistorPower-SideConnection4B1RS-ExternalSenseResistorLoad-SideConnection5A3OUTOutputVoltage.VOUTisproportionaltoVSENSE=VRS+-VRS-.6B3SHDNActive-LowShutdownInput.ConnecttoVDDfornormaloperation.MAX4428436V,InputCommon-Mode,High-Precision,Low-PowerCurrent-SenseAmplifierwww.maximintegrated.comMaximIntegrated│10PinDescriptionPinConfigurationsMAX44284SOT23TOPVIEWGNDRS+1VDD23RS-6SHDN5OUT+4A1A2A3B1B2B3RS+VDDOUTRS-GNDSHDN+TOPVIEWMAX44284WLPDetailedDescriptionTheMAX44284familyfeaturesasingle-supply;high-accuracyunidirectional,current-senseamplifierinvariousgainoptionsanda-0.1Vto36Vinputcommon-moderangethatisindependentofsupplyvoltage(VDD).TheMAX44284isidealformanybattery-powered,handhelddevicesbecauseitusesonlymaximum31.2μAquiescentsupplycurrenttoextendbatterylife.Thedevice’slowinputoffsetvoltage,tightgainerror,andlowtemperaturedriftcharacteristicsallowtheuseofsmall-senseresistorsforcurrentmeasurementstoimprovepower-supplycon-versionefficiencyandaccuracyofmeasurements.Thisfeatureallowsmonitoringofpower-supplyloadcurrenteveniftherailisshortedtoground.High-sidecurrentmonitoringdoesnotinterferewiththegroundpathoftheloadbeingmeasured,makingtheICparticularlyusefulinawiderangeofhigh-reliabilitysystems.Becauseofitsextendedcommon-moderangebelowground,thispartcanalsobeusedasalow-sidecurrentsensingelement.ShutdownTheMAX44284featuresactive-lowlogicshutdowninputtoreducethesupplycurrent.DriveSHDNhighfornormaloperation.DriveSHDNlowtoplacethedeviceinshut-downmode.Inshutdownmode,thesupplycurrentdrawnfromtheVDDislessthan1μA(max).PrecisionTheMAX44284usescapacitive-coupledInstrumentationamplifierarchitecturethatenablestheparttoachieveoverthetopcommon-modevoltageranges,highpowerefficiency,highgainaccuracy,andlow-powerdesign.LowOffsetVoltageandLowGainErrorTheMAX44284utilizesCapacitive-CoupledChopperInstrumentationAmplifier(CCIA)architecturetoachievealow-inputoffsetvoltageoflessthan10µA.Thesetech-niquesalsoenableextremelylow-inputoffsetvoltagedriftovertimeandtemperatureto50nV/°C.TheprecisionVOSspecificationallowsaccuratecurrentmeasurementswithlowervaluesofcurrent-senseresistors,thusreducingpowerdissipationinbattery-poweredsystems,aswellasloadregulationissuesinlow-voltageDCpowersupplies.Workingwitherrortoleranceswithveryfewinternalblocksinthisarchitectureisinstrumentalinachievingagainerroroflessthan0.20%overtheentiretemperaturerangeof-40°Cto+125°C.ApplicationsInformationInputDifferentialSignalRangeTheMAX44284’sinputstructureisoptimizedforsens-ingsmalldifferentialsignalsaslowas3.4mVfullscale(VFS)forhighefficiencywithlowestpowerdissipationinthesenseresistor,or110mVfullscaleforhighdynamicrange.TheinputdifferentialsignalrangeisdeterminedbythefollowingequationfortheMAX44248family.()DDSENSERANGEVVGAIN=TheinputdifferentialvoltagerangeisestimatedforVDDfrom1.7Vto5.5VfordifferentgainvaluesoftheMAX44284asshowninTable1Ideally,themaximumloadcurrentdevelopsthefull-scalesensevoltageacrossthecurrent-senseresistor.Choosethegainneededtoyieldthemaximumoutputvoltagerequiredfortheapplication:OUTSENSEVGAINV=×ChoosingtheSenseResistorVoltageLossAhighRSENSEvaluecausesthepower-sourcevoltagetodropduetoIRloss.Forminimalvoltageloss,usethelowestRSENSEvalue.AccuracyUsethebelowlinearequationtocalculatetotalerror:()()OUTSENSEOSVGAINGEVGAINV=±×±×Table1.VSENSEInputRangePARTGAIN(V/V)VSENSERANGE(mV)withVDD(1.7V)VSENSERANGE(mV)withVDD(5.5V)MAX44284F5034110MAX44284H1001755MAX44284W2008.527.5MAX44284E5003.411MAX4428436V,InputCommon-Mode,High-Precision,Low-PowerCurrent-SenseAmplifierwww.maximintegrated.comMaximIntegrated│11AhighRSENSEvalueallowslowercurrentstobemea-suredmoreaccuratelybecauseoffsetsarelesssignificantwhenthesensevoltageislarger.Notethatthetoler-anceandtemperaturecoefficientofthechosenresistorsdirectlyaffecttheprecisionofanymeasurementsys-tem.Forbestperformance,selectRSENSEtoprovideapproximatelymaximuminputdifferentialsensevoltageof110mV(MAX44284F)or55mV(MAX44284H)or27.5mV(MAX44284W)or11mV(MAX44284E)ofsensevoltageforthefull-scalecurrentineachapplication.Senseresistorsof5mΩto100mΩareavailablewith1%accuracyorbetter.EfficiencyandPowerDissipationAthighcurrentlevels,theI2RlossesinRSENSEcanbesignificant.Thisshouldbetakenintoconsiderationwhenchoosingtheresistorvalueanditspowerdissipation(wattage)rating.Thesenseresistor’svaluewilldriftifitisallowedtoheatupexcessively.TheprecisionVOSoftheMAX44284allowstheuseofsmallsenseresistorstoreducepowerdissipationandreducehotspots.KelvinConnectionsBecauseofthehighcurrentsthatmayflowthroughRSENSEbasedontheapplication,takecaretoeliminatesolderandparasitictraceresistancefromcausingerrorsinthesensevoltage.Eitheruseafour-terminalcurrent-senseresistororuseKelvin(forceandsense)PCBlayouttechniques.InputFilteringSomeapplicationsofcurrent-senseamplifiersneedtomeasurecurrentsaccuratelyeveninthepresenceofbothdifferentialandcommon-moderipple,aswellasawidevarietyofinputtransientconditions.TheMAX44284allowstwomethodsoffilteringtohelpimproveperformanceinthepresenceofinputcommon-modevoltageandinputdifferentialvoltagetransients.Figure1showsadifferentialinputfilter.ThecapacitorCINacrossRS+andRS-alongwiththeresistorRINhelpsfilteragainstinputdifferentialvoltagesandpreventsthemfromreachingtheMAX44284.ThecornerfrequencyofthisfilterisdeterminedbythechoiceofRIN,CIN.Figure2showsacommon-modeinputfilter.Thechoiceofcapaci-tancedependsoncornerfrequencyafterRINischosen.Incaseofmismatchorerrorinapplicationdesign,anadditionalDCerrorisaccumulatedasoffsetvoltageandincreasedgainerror.()()OSINOFFSETINBIASVRIDRI=×+×DRINistheresistancemismatchinRINatRS+andRS-.IfDRINistoosmall,itseffectcanbeneglected.SinceIOFFSEToftheMAX44284issmallerthan2nA,andifwewanttomakesureVOSislesserthan1µVrange,choosing()INOSOFFSETRVI<÷Figure1.DifferentialInputFilteringFigure2.InputCommon-ModeFilteringMAX4428436V,InputCommon-Mode,High-Precision,Low-PowerCurrent-SenseAmplifierwww.maximintegrated.comMaximIntegrated│12GNDCINRINRINLOADRSENSECINOUTMAX44284RS-RS+GNDCINRINRINLOADRSENSECINOUTMAX44284RS-RS+GNDRINRINLOADRSENSEOUTMAX44284RS-RS+CINForgainerror,itdependsonitsinputimpedanceandRIN.ININRGainError2Z−=×AvoidadditionalgainerrorshiftduetotheeffectofRIN.Forgainerror,theMAX44284is0.15%.IfthemarginofadditionaleffectofRINresultsinagainerrorshiftoflessthan0.02%,then:ININ0.02%R6002Z<=W×SoRINcanbechosen≤500Ω.OutputFilteringTheinternalarchitectureoftheMAX44284suppressestheDCoffset,1/fnoise,andaccumulatesathigherfrequenciessothattheycanbefilteredout.Hence,minuteACdisturbancescanbeobservedat10kHzand20kHz.ItisrecommendedtoaddanoutputfilteraftertheMAX44284toavoidnoiseandunwantedfrequencydisturbancesattheoutputwith4kHz-3dBfc(seeFigure3).(SuggestedvaluesofCandR:22nFand1.8kΩ,respectively.)BidirectionalApplicationBattery-poweredsystemsmayrequireaprecisebidirectionalcurrent-senseamplifiertoaccuratelymonitorthebattery’schargeanddischargecurrents.MeasurementsofthetwoseparateoutputswithrespecttoGNDyieldanaccuratemeasureofthechargeanddischargecurrents,respectively(Figure4).Figure3.FilteringFigure4.BidirectionalApplicationMAX4428436V,InputCommon-Mode,High-Precision,Low-PowerCurrent-SenseAmplifierwww.maximintegrated.comMaximIntegrated│13RS-RRS+RINRINCIN2RSENSEVBATTOUTMAX44284LOADCCINCINTOWALL-CUBECHARGERRS+OUTRS-RS+OUTRS-RSENSEILOADLOADµCVDD=3.3VVBATTUPTO36VMAX44284MAX44284ADCADC+Denotesalead(Pb)-free/RoHS-compliantpackage*Futureproduct—Contactfactoryforavailability.PARTGAIN(V/V)TEMPRANGEPIN-PACKAGETOPMARKMAX44284FAWT+50-40°Cto+125°C6WLP+CXMAX44284FAUT+50-40°Cto+125°C6SOT23+ACSFMAX44284FAUT/V+T*50-40°Cto+125°C6SOT23—MAX44284HAWT+100-40°Cto+125°C6WLP+CYMAX44284HAUT+100-40°Cto+125°C6SOT23+ACSGMAX44284WAWT+200-40°Cto+125°C6WLP+CZMAX44284WAUT+200-40°Cto+125°C6SOT23+ACSHMAX44284EAWT+500-40°Cto+125°C6WLP+DAMAX44284EAUT+500-40°Cto+125°C6SOT23+ACSIMAX4428436V,InputCommon-Mode,High-Precision,Low-PowerCurrent-SenseAmplifierwww.maximintegrated.comMaximIntegrated│14OrderingInform