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INA220高侧或低侧双向电流和功率监 感测的总线电压范围：0V

和功率监测计。INA220监测分流器压降和电源电压。计算出功率的瓦特值。I2C或SMBUS兼容接口具有16个可编程地址。INA220的独立分流输入允许其应(2.56MHz)I2CSMBUS

B级。

INA2200V26V范围内感测总线中的分压，适CPU3V5.5V单度范围为-40°C至125°C。封封装尺寸（标称值VSSOP3.00mmx(1)SupplySupply(0to+3.3VBusVoltageVS(Supply×-R1FCurrentPowerAnIMPORTANTNOTICEattheendofthisdatasheetaddressesavailability,warranty,changes,useinsafety-criticalapplications,inlectualpropertymattersandotherimportantdiers.PRODUCTIONDATA.EnglishDataSheet:特 应用范 说 修订历史记 Related PinConfigurationand Absoluteum ESD Thermal Electrical BusTimingDiagram Typical Detailed Feature

DeviceFunctional Register Applicationand Application Typical Power Layout Layout 器件和文档支 相关文 社区资 商 静电放 机械、封装和可订购信 ChangesfromRevisionD(September2010)toRevision 已更改首页图 Changedpinnamesinthepin ChangedthetemperaturevaluesintheAbsoluteumRatings ChangedAmbienttemperaturefrom–25to–40intheMIN DeletedTemperatureRangeparametersfromElectrical ChangedI2Ctimingspecchangebasedoncharacterization ChangesfromRevisionC(September,2009)toRevision 已更改B级器件的高精度要点（位于特性中）“1%”至 已添加有关器件A级和B级型号的新段落至说明部 AddednewrowtoPackagingInformationtabletoshownewB-grade AddedB-gradecolumnsinElectricalCharacteristicsforMIN,TYPandMAX ChangedCurrentSenseGainErrorovertemperaturespecificationfrom10ppm/°Cto AddedConfigure/Measure/Calculate ChangesfromRevisionB(June,2009)toRevision Changedspecifiedtemperaturerangefrom–25°Cto ChangedOffsetVoltage(RTI)vsTemperatureminimumspecificationfrom0.1μV/°Cto0.16 ChangedTypicalCharacteristics:Figure3,Figure4,Figure5,Figure ChangedTypicalCharacteristics:Figure9,Figure RelatedCurrent/powermonitorwithwatchdog,peak-hold,andfastcomparatorZero-drift,low-cost,ogcurrentshuntmonitorseriesinsmallZero-drift,bidirectionalcurrentpowermonitorwithtwo-wirePinConfigurationandDGSPackage10-PINTop

65748657483921Pin1DigitalAddresspin.ConnecttoGND,SCL,SDA,orVS.Table1showspinsettingsandcorresponding2DigitalAddresspin.ConnecttoGND,SCL,SDA,orVS.Table1showspinsettingsandcorresponding3—Nointernal4DigitalSerialbusdata5DigitalSerialbusclock6Powersupply,3Vto5.578ogBusvoltage9ogNegativedifferentialshuntvoltage.Connecttonegativesideofshuntresistor.Busvoltageismeasuredfromthispintoground.ogPositivedifferentialshuntvoltage.ConnecttopositivesideofshuntAbsoluteumoveroperatingfree-airtemperaturerange(unlessotherwiseSupply6VIN+,IN–Differential(VIN+)–(VVCommon-mode(VIN++VIN-)/VVoltageatVBUSVVoltageatSDAGND–6VVoltageatSCLGND–VS+VInputcurrentintoany5OperatingJunctionStorageStressesbeyondthoselistedunderAbsoluteumRatingsmaycausepermanentdamagetothedevice.Thesearestressratingsonly,whichdonotimplyfunctionaloperationofthedeviceattheseoranyotherconditionsbeyondthoseindicatedunder OperatingConditions.Exposuretoabsolute-um-ratedconditionsforextendedperiodsmayaffectdevicereliability.IN+andIN–mayhaveadifferentialvoltageof–26to26V;however,thevoltageatthesepinsmustnotexceedtherangeof–0.3to26ESD Humanbodymodel(HBM),perANSI/ESDA/JEDECJS-001,allVChargeddevicemodel(CDM),perJEDECspecificationJESD22-C101,allMachinemodel JEP155statesthat500-VHBMallowssafemanufacturingwithastandardESDcontrol JEP157statesthat250-VCDMallowssafemanufacturingwithastandardESDcontrolmendedOperatingoveroperatingfree-airtemperaturerange(unlessotherwise(VN++VIN-)/VSupplyVAmbientThermalDGS10Junction-to-ambientthermalJunction-to-case(top)thermalJunction-to-boardthermal(1)Formoreinformationabouttraditionalandnewthermalmetrics,seetheSemiconductorandICPackageThermalMetricsapplicationreport,SPRA953.ElectricalatTA=25°C,VS=3.3V,VN+=12V,VSHUNT=(VN+–VN–)=32mV,VVBUS=12V,PGA=/1,andBRNG(1)=1,TESTPGA=00Full-scalecurrentsense(input)voltagePGA=00PGA=00PGA=00Busvoltage(inputBRNG=00VBRNG=00VVIN+=0to26PGA=PGA=OffsetPGA=PGA=TA=–40°CtoversusVS=3to5.5CurrentsensegainTA=–40°Cto11IN+pininputActiveIN–pininputActiveVBUSpininputActiveIN+pininputIN–pininputDCADCbasicShunt1-LSBstepBus1-LSBstep44overTemperatureTA=–40°Cto85°CBusvoltagemeasurementVBUS=12overTemperatureTA=–40°Cto85°CADCADCconversion12-11-10-9-Minimumconvertinputlow44BRNGisbit13oftheConfigurationRegister00h(seeFigureThisparameteronlyexpressesthefull-scalerangeoftheADCscaling.Innoeventshouldmorethan26VbeappliedtothisIndicatesimprovedspecificationsoftheTheinputimpedanceofthispinmayvaryapproximayInputleakageispositive(currentflowingintothepin)fortheconditionsshownatthetopofthetable.Negativeleakagecurrentscanoccurunderdifferentinputconditions.SMBustimeoutintheINA220resetstheinterfaceanytimeSCLorSDAislowformorethan28ElectricalCharacteristicsatTA=25°C,VS=3.3V,VN+=12V,VSHUNT=(VN+–VN–)=32mV,VVBUS=12V,PGA=/1,andBRNG(1)=1,TESTDIGITALINPUTS(SDAasInput,SCL,A0,Input33Leakageinput0≤VIN≤ VIHinputlogic0.760.76VVILinputlogic0.30.3VLogic0outputISINK=3VVOUT= POWEROperatingsupply33V Quiescentcurrent,power-down66Power-onreset22VBusTimingDiagramFASTHIGH-SPEED BusfreetimebetweenSTOPandSTARTHoldtimeafterrepeatedSTARTconditionAfterthisperiod,thefirstclockisSTOPconditionsetupDatahold00DatasetupSCLclockLOWSCLclockHIGHDatafallClockfallClockriseClockrisetimeforSCLK≤100t(HIGH)t(HIGH)PSFigure1.BusTimingTypicalatTA=25°C,VS=3.3V,VN+=12V,VSHUNT=(VN+–VN–)=32mV,PGA=/1,andBRNG=1,unlessotherwise0GainGain

OffsetOffset0

160mV

320mV

InputFrequency

80mV 40mV Temperature

GainGainError0

Figure2.Frequency320mV 160mV80mV40mV

Figure3.ADCShuntOffsetvs32V32V16VOffsetOffset50 Temperature

Temperature

GainGainError0

Figure4.ADCShuntGainErrorvs Figure5.ADCBusVoltageOffsetvsNLNL05 Temperature

)Figure6.ADCBusGainErrorvsFigure7.IntegralNonlinearityvsInputTypicalCharacteristicsatTA=25°C,VS=3.3V,VN+=12V,VSHUNT=(VN+–VN–)=32mV,PGA=/1,andBRNG=1,unlessotherwisenputnputCurrents

VS+=VS+=

QQ

VS=0

=

VS=

VS+=

0

VINVoltage TemperatureFigure8.InputCurrentsWithLargeDifferentialVoltages(VIN+at12V,SweepOfVIN–)VS=86VS=

QQ

Figure9.ActiveIQvs420 Temperature

SS= 0

SCLFrequency

BFigure10.ShutdownIQvs BU () 5V )3%BusVoltage%BusVoltageQQ0 5V 3.3V

0Figure11.ActiveIQvsTwo-WireClockVS=

VS= SCLFrequencyFigure12.TotalFigure12.TotalPercentBusVoltageureShutdownvs-WireockvsSupplyDetailedTheINA220isadigitalcurrentsenseamplifierwithanI2C-and patibleinterface.Itprovidesdigitalcurrent,voltage,andpowerreadingsnecessaryforaccuratedecision-makinginprecisely-controlledsystems.Programmableregistersallowflexibleconfigurationformeasurementresolutionaswellascontinuous-versus-triggeredoperation.Detailedregisterinformationappearsattheendofthisdatasheet,beginningwithTable2.SeeFunctionalBlockDiagramforablockdiagramoftheINA220device.FunctionalBlockDataData(InConfigurationShuntFullScaleBusBusReadFeatureBasicADCThetwooginputstotheINA220,IN+andIN–,connecttoashuntresistorinthebusofinterest.BusvoltageismeasuredatVBUSpin.TheINA220istypicallypoweredbyaseparatesupplyfrom3to5.5V.Thebusbeingsensedcanvaryfrom0to26V.Itrequiresnospecialconsiderationsforpower-supplysequencing(forexample,abusvoltagecanbepresentwiththesupplyvoltageoff,andvice-versa).TheINA220sensesthesmalldropacrosstheshuntforshuntvoltage,andsensesthevoltagewithrespecttogroundfromVBUSpinforthebusvoltage.WhentheINA220isinthenormaloperatingmode(thatis,MODEbitsoftheConfigurationregisteraresetto111),itcontinuouslyconvertstheshuntvoltageuptothenumbersetintheshuntvoltageaveragingfunction(Configurationregister,SADCbits).Thedevicethenconvertsthebusvoltageuptothenumbersetinthebusvoltageaveraging(Configurationregister,BADCbits).TheModecontrolintheConfigurationregisteralsoAllcurrentandpowercalculationsareperformedinthebackgroundanddonotcontributetoconversiontime;conversiontimesshowninElectricalCharacteristicscanbeusedtodeterminetheactualconversiontime.Power-downmodereducesthequiescentcurrentandturnsoffcurrentintotheINA220inputs,avoidinganysupplydrain.Fullrecoveryfrompower-downrequires40μs.ADCoffmode(setbytheConfigurationregister,MODEbits)stopsallconversions.Intriggeredmode,writinganyofthetriggeredconvertmodesintotheConfigurationregister(evenifthedesiredmodeisalreadyprogrammedintotheregister)triggersasingle-shotconversion.AlthoughtheINA220canbereadatanytime,andthedatafromthelastconversionremainavailable,theConversionReadybit(Statusregister,CNVRbit)isprovidedtohelpcoordinateone-shotortriggeredconversions.TheConversionReadybitissetafterallconversions,averaging,andmultiplicationoperationsarecomplete.TheConversionReadybitclearsunderanyoftheseWritingtotheConfigurationregister,exceptwhenconfiguringtheMODEbitsforpowerdownorADCoff(disable)modesReadingtheStatusTriggeringasingle-shotconversionwiththeconvertPowerCurrentandbusvoltageareconvertedatdifferentpointsintime,dependingontheresolutionandaveragingmodesettings.Forinstance,whenconfiguredfor12-bitand128-sampleaveraging,upto68msintimebetweensamplingthesetwovaluesispossible.Again,thesecalculationsareperformedinthebackgroundanddonotaddtotheoverallconversiontime.PGAIflargerfull-scaleshuntvoltagesaredesired,theINA220providesaPGAfunctionthatincreasesthefull-scalerangeupto2,4,or8times(320mV).Additionally,thebusvoltagemeasurementhastwofull-scaleranges:16or32V.CompatibilityWithTIHotSwapTheINA220isdesignedforcompatibilitywithhotswapcontrollerssuchtheTITPS2490.TheTPS2490usesahigh-sideshuntwithalimitat50mV;theINA220full-scalerangeof40mVenablestheuseofthesameshuntforcurrentsensingbelowthislimit.Whensensingisrequiredat(orthrough)the50-mVsensepointoftheTPS2490,thePGAoftheINA220canbesetto/2toprovidean80-mVfull-scalerange.DeviceFunctionalFilteringandInputMeasuringcurrentisoftennoisy,andsuchnoisecanbedifficulttodefine.TheINA220offersseveraloptionsforfilteringbychoosingresolutionandaveragingintheConfigurationregister.Thesefilteringoptionscanbesetindependentlyforeithervoltageorcurrentmeasurement.TheinternalADCisbasedonadelta-sigma(ΔΣ)front-endwitha500-kHz(±30%)typicalsamplingrate.Thisarchitecturehasgoodinherentnoiserejection;however,transientsthatoccuratorveryclosetothesamplingrateharmonicscancauseproblems.Becausethesesignalsareat1MHzandhigher,theycanbedealtwithbyincorporatingfilteringattheinputoftheINA220.Thehighfrequencyenablestheuseoflow-valueseriesresistorsonthefilterfornegligibleeffectsonmeasurementaccuracy.Ingeneral,filteringtheINA220inputisonlynecessaryiftherearetransientsatexactharmonicsofthe500-kHz(±30%)samplingrate(>1MHz).Filterusingthelowestpossibleseries andceramiccapacitor.TI mendsvaluesof0.1to1μF.Figure14showstheINA220withanadditionalfilteraddedattheinput.OverloadconditionsareanotherconsiderationfortheINA220inputs.TheINA220inputsarespecifiedtotolerate26Vacrosstheinputs.Alargedifferentialscenariomightbeashorttogroundontheloadsideoftheshunt.Thistypeofeventcanresultinfullpower-supplyvoltageacrosstheshunt(aslongthepowersupplyorenergystoragecapacitorssupportit).Itmustberememberedthatremovingashorttogroundcanresultininductivekickbacksthatcouldexceedthe26-Vdifferentialandcommon-moderatingoftheINA220.InductivekickbackvoltagesarebestdealtwithbyZener-typetransient-absorbingdevicescombinedwithsufficientenergystorageDeviceFunctionalModesInapplicationsthatdonothavelargeenergystorageelectrolyticsononeorbothsidesoftheshunt,aninputoverstressconditionmayresultfromanexcessivedV/dtofthevoltageappliedtotheinput.Ahardphysicalshortisthemostlikelycauseofthisevent,particularlyinapplicationswithnolargeelectrolyticspresent.ThisproblemoccursbecauseanexcessivedV/dtcanactivatetheESDprotectionintheINA220insystemswherelargecurrentsareavailable.Testinghasdemonstratedthattheadditionof10-ΩresistorsinserieswitheachinputoftheINA220sufficientlyprotectstheinputsagainstdV/dtfailureuptothe26-VratingoftheINA220.Theseresistorshavenosignificanteffectonaccuracy. RFILTER RFILTER

Supply0.1µFto1µFCeramic

3.3VPower DataPower

IC-CurrentCurrent

ClockFigure14.INA220WithInputProgrammingtheINA220CalibrationCurrent_LSBRegisterDetailsshowsthedefaultpower-upstatesoftheregisters.Theseregistersarevolatile,andifprogrammedtoanythingotherthandefaultvalues,theymustbereprogrammedateverydevicepower-up.TheCalibrationRegisteriscalculatedbasedonEquation1.ThisequationincludesthetermCurrent_LSB,whichistheprogrammedvaluefortheLSBfortheCurrentRegister(04h).TheCurrent_LSBvalueisusedtoconvertthevalueintheCurrentRegister(04h)totheactualcurrentinamperes.ThehighestresolutionfortheCurrentRegister(04h)canbeobtainedbyusingthesmallestallowableCurrent_LSBbasedonthe umexpectedcurrentasshowninEquation2.Whilethisvalueyieldsthehighestresolution,itiscommontoselectavaluefortheCurrent_LSBtothenearestroundnumberabovethisvaluetosimplifytheconversionoftheCurrentRegister(04h)andPowerRegister(03h)toamperesandwattsrespectively.TheRSHUNTtermisthevalueoftheexternalshuntusedtodevelopthedifferentialvoltageacrosstheinputpins.ThePowerRegister(03h)isinternallysettobe20Current_LSBCal=0.04096isaninternalfixedvalueusedtoensurescalingismaintainedumExpectedCurrent_LSBistheprogrammedvaluefortheLSBfortheCurrentRegisterumExpectedCurrent_LSB wer_LSB=20 ProgrammingProgrammingShuntvoltageiscalculatedbymultiplyingtheShuntVoltageRegistercontentswiththeShuntVoltageLSBof10μV.TheBusVoltageregisterbitsarenotright-aligned.TocomputethevalueoftheBusVoltage,BusVoltageRegistercontentsmustbeshiftedrightbythreebits.ThisshiftputstheBD0bitintheLSBpositionsothatthecontentscanbemultipliedbytheBusVoltageLSBof4-mVtocomputethebusvoltagemeasuredbythedevice.AfterprogrammingtheCalibrationRegister,thevalueexpectedintheCurrentRegister(04h)canbecalculatedbymultiplyingtheShuntVoltageregistercontentsbytheCalibrationRegisterandthendividingby4096asshowninEquation4.Toobtainavalueinamperes,theCurrentregistervalueismultipliedbytheprogrammedCurrent_LSB.CurrentRegisterShuntVoltageRegisterCalibration ThevalueexpectedinthePowerregister(03h)canbecalculatedbymultiplyingtheCurrentregistervaluebytheBusVoltageregistervalueandthendividingby5000asshowninEquation5.PowerRegistercontentismultipliedbyPowerLSBwhichis20timestheCurrent_LSBforapowervalueinwatts.PowerRegisterCurrentRegisterBusVoltageProgrammingtheINA220PowerMeasurementCalibrationRegisterand

TheCalibrationregistermakesitpossibletosetthescalingoftheCurrentandPowerregisterstowhatevervaluesaremostusefulforagivenapplication.OnestrategymaybetosettheCalibrationregistersuchthatthelargestpossiblenumberisgeneratedintheCurrentregisterorPowerregisterattheexpectedfull-scalepoint;thisapproachyieldsthehighestresolution.TheCalibrationregistercanalsobeselectedtoprovidevaluesintheCurrentandPowerregistersthateitherprovidedirectdecimalequivalentsofthevaluesbeingmeasured,oryieldaroundLSBnumber.Afterthesechoiceshavebeenmade,theCalibrationregisteralsoofferspossibilitiesforend-usersystem-levelcalibration,wherethevalueisadjustedslightlytocanceltotalsystemerror.Afterdeterminingtheexactcurrentbyusinganexternalammeter,thevalueoftheCalibrationRegistercanthenbeadjustedbasedonthemeasuredcurrentresultoftheINA220tocancelthetotalsystemerrorasshowninEquation6.CalCalSimpleCurrentShuntMonitorUsage(NoProgrammingTheINA220canbeusedwithoutanyprogrammingifitisonlynecessarytoreadashuntvoltagedropandbusvoltagewiththedefault12-bitresolution,320-mVshuntfull-scalerange(PGA=/8),32-Vbusfull-scalerange,andcontinuousconversionofshuntandbusvoltage.Withoutprogramming,currentismeasuredbyreadingtheshuntvoltage.TheCurrentregisterandPowerregisterareonlyavailableiftheCalibrationregistercontainsaprogrammedvalue.BusTheINA220offerscompatibilitywithbothI2CandSMBusinterfaces.TheI2CandSMBusprotocolsareessentiallycompatiblewithoneanother.TheI2Cinterfaceisusedthroughoutthisdatasheetastheprimaryexample,withSMBusprotocolspecifiedonlywhenadifferencebetweenthetwosystemsisbeingaddressed.Twolines,SCLandSDA,connecttheINA220tothebus.BothSCLandSDAareopen-drainconnections.Thedevicethatinitiatesthetransferiscalledamaster,andthedevicescontrolledbythemasterareslaves.Thebusmustbecontrolledbyamasterdevicethatgeneratestheserialclock(SCL),controlsthebusaccess,andgeneratesSTARTandSTOPconditions.Toaddressaspecificdevice,themasterinitiatesaSTARTconditionbypullingthedatasignalline(SDA)fromahightoalowlogiclevelwhileSCLishigh.AllslavesonthebusshiftintheslaveaddressbyteontherisingedgeofSCL,withthelastbitindicatingwhetherareadorwriteoperationisintended.Duringtheninthclockpulse,theslavebeingaddressedrespondstothemasterbygeneratinganAcknowledgeandpullingSDAlow.Datatransferistheninitiatedandeightbitsofdataaresent,followedbyanAcknowledgebit.Duringdatatransfer,SDAmustremainstablewhileSCLishigh.AnychangeinSDAwhileSCLishighisinterpretedasaSTARTorSTOPcondition.Afteralldatahavebeentransferred,themastergeneratesaSTOPcondition,indicatedbypullingSDAfromlowtohighwhileSCLishigh.TheINA220includesa28-mstimeoutonitsinterfacetopreventlockingupanSMBus.SerialBusTocommunicatewiththeINA220,themastermustfirstaddressslavedevicesthroughaslaveaddressbyte.Theslaveaddressbyteconsistsofsevenaddressbits,andadirectionbitindicatingtheintentofexecutingareadorwriteoperation.TheINA220hastwoaddresspins,A0andA1.Table1describesthepinlogiclevelsforeachofthe16possibleaddresses.ThestateofpinsA0andA1issampledoneverybuscommunicationandshouldbesetbeforeanyactivityontheinterfaceoccurs.Theaddresspinsarereadatthestartofeachcommunicationevent.Table1.INA220AddressPinsandSlaveSLAVESerialTheINA220operatesonlyasaslavedeviceontheI2CbusandSMBus.Connectionstothebusaremadebytheopen-drainI/OlinesSDAandSCL.TheSDAandSCLpinsfeatureintegratedesuppressionfiltersandSitttriggerstominimizetheeffectsofinputesandbusnoise.TheINA220supportsthetransmissionprotocolforfast(1-kHzto400-kHz)andhigh-speed(1-kHzto2.56-MHz)modes.Alldatabytesaretransmittedmostsignificantbytefirst.WritingtoandReadingfromtheAccessingaparticularregisterontheINA220is plishedbywritingtheappropriatevaluetotheregisterpointer.RefertoTable2foracompletelistofregistersandcorrespondingaddresses.Thevaluefortheregisterpointer,asshowninFigure18,isthefirstbytetransferredaftertheslaveaddressbytewiththeR/WbitLOW.EverywriteoperationtotheINA220requiresavaluefortheregisterpointer.Writingtoaregisterbeginswiththefirstbytetransmittedbythemaster.Thisbyteistheslaveaddress,withtheR/WbitLOW.TheINA220thenacknowledgesreceiptofavalidaddress.Thenextbytetransmittedbythemasteristheaddressoftheregistertowhichdatawillbewritten.Thisregisteraddressvalueupdatestheregisterpointertothedesiredregister.Thenexttwobytesarewrittentotheregisteraddressedbytheregisterpointer.TheINA220acknowledgesreceiptofeachdatabyte.ThemastermayterminatedatatransferbygeneratingaSTARTorSTOPcondition.WhenreadingfromtheINA220,thelastvaluestoredintheregisterpointerbyawriteoperationdetermineswhichregisterisreadduringareadoperation.Tochangetheregisterpointerforareadoperation,anewvaluemustbewrittentotheregisterpointer.Thiswriteis plishedbyissuingaslaveaddressbytewiththeR/WbitLOW,followedbytheregisterpointerbyte.Noadditionaldataarerequired.ThemasterthengeneratesaSTARTconditionandsendstheslaveaddressbytewiththeR/WbitHIGHtoinitiatethereadcommand.Thenextbyteistransmittedbytheslaveandisthemostsignificantbyteoftheregisterindicatedbytheregisterpointer.ThisbyteisfollowedbyanAcknowledgefromthemaster;thentheslavetransmitstheleastsignificantbyte.Themasteracknowledgesreceiptofthedatabyte.ThemastermayterminatedatatransferbygeneratingaNotAcknowledgeafterreceivinganydatabyte,orgeneratingaSTARTorSTOPcondition.Ifrepeatedreadsfromthesameregisteraredesired,itisnotnecessarytocontinuallysendtheregisterpointerbytes;theINA220retainstheregisterpointervalueuntilitischangedbythenextwriteoperation.Figure15andFigure16showwriteandreadoperationtimingdiagrams,respectively.Notethatregisterbytesaresentmost-significantbytefirst,followedbytheleastsignificantbyte.Figure17showsthetimingdiagramfortheSMBusAlertresponseoperation.Figure18showsatypicalregisterpointerconfiguration. Figure15.TimingDiagramforWriteWordD7D7D6D5D4D3D2D1Figure16.TimingDiagramforReadWordZHCSFN7E–JUNE2009–REVISEDJANUARY

ACK

NACK

Frame1SMBusALERTResponseAddress Frame2SlaveAddressNOTE(1):ThevalueoftheSlaveAddressByteisdeterminedbythesettingsoftheA0andA1pins.RefertoTableFigure17.TimingDiagramforSMBus

ACKFrame1TwoWireSlaveAddress

ACKNOTE(1):ThevalueoftheSlaveAddressByteisdeterminedbythesettingsoftheA0andA1pins.RefertoTableFigure18.TypicalRegisterPointerHigh-SpeedTwo-WireWhenthebusisidle,boththeSDAandSCLlinesarepulledhighbythepullupdevices.Themastergeneratesastartconditionfollowedbyavalidserialbytecontaininghigh-speed(HS)mastercode00001XXX.Thistransmissionismadeinfast(400kbps)orstandard(100kbps)(F/S)modeatnomorethan400kbps.TheINA220doesnotacknowledgetheHSmastercode,butdoesrecognizeitandswitchesitsinternalfilterstosupport2.56-MbpsThemasterthengeneratesarepeatedstartcondition(arepeatedstartconditionhasthesametimingasthestartcondition).Afterthisrepeatedstartcondition,theprotocolisthesameasF/Smode,exceptthattransmissionspeedsupto2.56Mbpsareallowed.Insteadofusingastopcondition,repeatedstartconditionsshouldbeusedtosecurethebusinHS-mode.ASTOPconditionendstheHS-modeandswitchesalltheinternalfiltersoftheINA220tosupporttheF/Smode.SeeBusTimingDiagramDefinitions(1)andFigure1fortiming.Power-UpPower-upconditionsapplytoasoftwareresetthroughtheRSTbit(bit15)intheConfigurationregister,ortheI2CbusGeneralCallReset.RegisterRegisterTheINA220usesabankofregistersforholdingconfigurationsettings,measurementresults,andstatusinformation.Table2summarizestheINA220registers;FunctionalBlockDiagramillustratestheregisters.Registercontentsareupdated4μsaftercompletionofthewritecommand.Therefore,a4-μsdelayisrequiredbetweencompletionofawritetoagivenregisterandasubsequentreadofthatregister(withoutchangingthepointer)whenusingSCLfrequenciesinexcessof1MHz.Table2.SummaryofRegisterREGISTERPOWER-ONAll-registerreset,settingsforbusvoltagerange,PGAgain,ADCShuntShuntvoltagemeasurementShunt—RBusBusvoltagemeasurementBus—RPowermeasurementRContainsthevalueofthecurrentflowingthroughtheshuntresistor.RCalSetsfull-scalerangeandLSBofcurrentandpowermeasurements.Overallsystemcalibration.Valuesbasedonastatisticalysisofaone-timesampleofdevices.Minimumandumvaluesarenotensuredandnotproductiontested.Condition:A0=A1=0.Type:R=Readonly,R/W=ThePowerregisterandCurrentregisterdefaultto0becausetheCalibrationregisterdefaultsto0,yieldingazerocurrentvalueuntiltheCalibrationregisterisprogrammed.RegisterAllINA220registers16-bitregistersareactuallytwo8-bitbytesthroughtheI2C- patibleConfigurationRegister(address=00h)[reset=Figure19.Configuration—R/W-R/W-R/W-1R/W-1R/W-1R/W-0R/W-0R/W-1R/W-1R/W-0R/W-0R/W-1R/W-1R/W-1R/W-1R/W- LEGEND:R/W=Read/Write;R=Readonly;-n=valueafter ResetBit15 Settingthisbitto1generatesasystemresetthatisthesameaspower-onreset.Resetsallregisterstodefaultvalues;thisbitself-clears. BusVoltageBit 0=16-V1=32-VFSR(default PGA(ShuntVoltageBits11,12 SetsPGAgainandrange.NotethatthePGAdefaultsto÷8(320-mVrange).Table3showsthegainandrangeforthevariousproductgainsettings.Table3.PGBitSettings[12:11]001±4001±8010±16011±320Shadedvaluesare BADCBusADCBits7–10 ThesebitsadjusttheBusADCresolution(9-,10-,11-,or12-bit)orsetthenumberofsamplesusedwhenaveragingresultsfortheBusVoltageRegister(02h). SADCShuntADCBits3–6 ThesebitsadjusttheShuntADCresolution(9-,10-,11-,or12-bit)orsetthenumberofsamplesusedwhenaveragingresultsfortheShuntVoltageRegister(01h).BADC(Bus)andSADC(Shunt)ADCresolution/averagingandconversiontimesettingsareshowninTableTable4.ADCSettings(SADC[6:3],BADCConversio14801011-27601112-532100012-532100121.06101042.13101184.2611008.51110117.02ShadedvaluesareX=Don'tTable4.ADCSettings(SADC[6:3],BADC[10:7])()Conversion111034.05111168.10 OperatingBits0–2 Selectscontinuous,triggered,orpower-downmodeofoperation.Thesebitsdefaulttocontinuousshuntandbusmeasurementmode.ThemodesettingsareshowninTable5.Table5.ModeSettings000Power-001Shuntvoltage,010Busvoltage,011Shuntandbus,100ADCoff101Shuntvoltage,110Busvoltage,111Shuntandbus,(1)ShadedvaluesareDataOutputShuntVoltageRegister(address=TheShuntVoltageregisterstoresthecurrentshuntvoltagereading,VSHUNT.ShuntVoltageregisterbitsareshiftedaccordingtothePGAsettingselectedintheConfigurationregister(00h).