SP1232F原版芯片datasheet

SP1232F原版芯片datasheetSP1232FWideInputRangeCC/CVSynchronousBuckRegulatorUnauthorizedPhotocopyandDuplicationProhibitedFeatures◆5V~32VSupplyVoltageRange◆36VInputVoltageSurge◆32VInputOverVoltageProtection◆2%VoltageReferenceAccuracy◆5%ConstantCurrentAccuracy◆ExternalOptionalCurrentLimitMode◆ProgrammableFrequency（60KHz~1MHz）◆BuiltinAdjustableLine-Compensation◆HiccupShortCircuitProtection◆DutyCycleRange(0~100%)◆InternalSoftStart3ms◆CC/CVModeControl◆SOP-8LPackageApplications◆CarChargers◆PortableChargerDevicesGeneralDescriptionTheSP1232FisasynchronousbuckRegulatorwithoutputcurrentupto3.1A.Itisdesignedtoallowforoperatingawidesupplyvoltagerangefrom5Vto32V.Theinternalcompensationrequiresaminimumnumberofreadilyavailablestandardexternalcomponents.TheSP1232FoperatesintheCC(ConstantoutputCurrent)modeorCV(ConstantoutputVoltage)mode,andtheOCPcurrentvalueissetbycurrentsensingpowerresistersorsettingnonpowerresisters.TheSP1232FissuitablefortheDC/DCswitchingpowerapplicationswhenrequestedthecurrentlimitfunction.ThedevicesareavailableinSOP-8Lpackageandrequireveryfewexternaldevicesforoperation.◆DC/DCConverterswithCurrentLimitTypicalApplicationCircuitFigure1TypicalApplicationofSP1232F(High-accuracyCurrentLimit)Note1：1.RCS=120mV/Ilimit.,RCSisPowerResistors.2.RT=24000K/fosc；Floatfrequencyis120KHz.　　　　深圳芯派科技ＴＥＬ：１３５　３０４５　２６４６　（唐生）ＩＣＱ：２９４　４３４　３３６２ＩＣＱ：２９４　４３５　３３６２Figure2TypicalApplicationofSP1232F(Low-costCurrentLimit)Note2：1.R3>25KΩ.R3isNonPowerResistors.2.Iout=3.1ArecommendR3=100KIout=2.4ArecommendR3=82K3.RT=24000K/fosc；Floatfrequencyis120KHz.PinFunctionDescriptionGNDFBRTSENVINSWGNDSWFigure3PinConfigurationOrderingandMarkingInformationAbsoluteMaximumRatingsNote3：1.Stresseslistedastheabove“AbsoluteMaximumRatings”maycausepermanentdamagetothedevice.Theseareforstressratings.Functionaloperationofthedeviceattheseoranyotherconditionsbeyondthoseindicatedintheoperationalsectionsofthespecificationsisnotimplied.Exposuretoabsolutemaximumratingconditionsforextendedperiodsmayremainpossibilitytoaffectdevicereliability.2.DevicesareESDsensitive.Handlingprecautionrecommended.3.θJAismeasuredinthenaturalconvectionatTA=25°ConahigheffectivethermalconductivitytestboardofJEDEC51-7thermalmeasurementstandard.RecommendedOperatingConditionsBlockDiagramVINFBSENFigure4BlockdiagramofSP1232FElectricalCharacteristicsV=12V,T=+25°C,unlessotherwisespecifiedFunctionalDescriptionCV/CCmodecontrolTheSP1232FprovidesCC/CVfunction.TheConstantoutputCurrentcontrolModeandConstantoutputVoltagecontrolMode.OverCurrentProtectionTheSP1232Fprovidesovercurrentprotection.AdropvoltageonthecurrentsensingresisterisovertheOCPvalue,theOCPfunctionwillshutdownthecontroller.SoftStartTheSP1232Fhasinternalsoftstartfunctiontocontrolriserateoftheoutputvoltageandlimitsthelargeinrushcurrentatstartup.Thetypicalsoftstartintervalisabout3mS.PoweronResetApower-onresetcircuitmonitorstheinputvoltage.Whentheinputvoltageexceeds4.5V,theconverterwillstartoperation.Onceinputvoltagefallsbelow4.3V,thecontrollerwillshutdown.OverTemperatureProtectionTheSP1232Fprovidesovertemperatureprotection.TheOTPwillshutdowntheconverterwhenjunctiontemperatureexceeds160℃.Oncethejunctiontemperaturecoolsdownbyapproximately40℃,theconverterwillresumenormaloperation.CurrentLimitProtectionTheSP1232FprovidestwokindsofcurrentlimitMode.WhentheSENPinseriesPowerResistorstotheload.Thecurrentlimitsetaccordingtothefollowingequation:SENR120mVit(A)CurrentLim=WhentheSENPinseriesNonPowerResistorstoGND.Thecurrentlimitsetaccordingtothefollowing:Rsen82K100KIout2.4A3.1AOscillatorFrequencyTheSP1232FoscillatorfrequencyissetbyasingleexternalresistorconnectedbetweentheRTpinandtheGNDpin.TheresistorshouldbelocatedveryclosetothedeviceandconnecteddirectlytothepinsoftheIC(RTandGND).TheoscillatorfrequencyriseswhentheresistorRTfalls.Todeterminethetimingresistanceforagivenswitchingfrequency,usetheequationbelow:TR24000Kf(KHz)=OutputShort-CircuitProtectionTheSP1232Fprovidesoutputshort-circuitprotectionfunction.WhenVOUTisshort(VFB<0.4V),theautorestartfunctioncanbestartedthatrestarttheregulatorcyclebycycle.Thecycletimeissetbyinternalcounter.Figure5short-circuitprotectiontimeAPPLICATIONINFORMATIONOutputVoltageSettingFigure6OutputVoltageSettingFigure6showstheconnectionsforsettingtheoutputvoltage.SelecttheproperratioofthetwofeedbackresistorsRFB1andRFB2basedontheoutputvoltage.Typically,useRFB2>10kΩanddetermineRFB1fromthefollowingequation:OUTFB1FB2VRR11.2⎛⎫=-⎪⎝⎭OutputCableResistanceCompensationTocompensateforresistivevoltagedropacrossthecharger'soutputcable,theSP1232Fintegratesasimple,user-programmablecablevoltagedropcompensationusingtheimpedanceattheFBpin.RFB1isthehighsideresistorofvoltagedivider.[]FB1OUTFB2FB1OUTRV(1)1.02I.2RR5⎡⎤=+⋅+⋅⋅⎢⎥⎣⎦Figure712Vinto5VoutCableCompensationInductorSelectionTheinductormaintainsacontinuouscurrenttotheoutputload.Thisinductorcurrenthasaripplethatisdependentontheinductancevalue:Higherinductancereducesthepeak-to-peakripplecurrent.Thetradeoffforhighinductancevalueistheincreaseininductorcoresizeandseriesresistance,andthereductionincurrenthandlingcapability.Ingeneral,selectaninductancevalueLbasedonripplecurrentrequirement:()OUTINOUTINOUTMAXRIPPLEVVVLVfIKSW⨯-=WhereVINistheinputvoltage,VOUTistheoutputvoltage,fSWistheswitchingfrequency,IOUTMAXisthemaximumoutputcurrent,andKRIPPLEistheripplefactor.Typically,chooseKRIPPLE=30%tocorrespondtothepeak-to-peakripplecurrentbeing30%ofthemaximumoutputcurrent.Withthisinductorvalue,thepeakinductorcurrentisIOUT×(1+KRIPPLE/2).Makesurethatthispeakinductorcurrentislessthanthecontroller’scurrentlimit.Finally,selecttheinductorcoresizesothatitdoesnotsaturateatthepeakinductorcurrent.InputCapacitorTheinputcapacitorneedstobecarefullyselectedtomaintainsufficientlylowrippleatthesupplyinputoftheconverter.AlowESRcapacitorishighlyrecommended.Sincelargecurrentflowsinandoutofthiscapacitorduringswitching,itsESRalsoaffectsefficiency.Theinputcapacitanceneedstobehigherthan100μF.Thebestchoiceistheceramictype,however,lowESRtantalumorelectrolytictypesmayalsobeusedprovidedthattheRMSripplecurrentratingishigherthan50%oftheoutputcurrent.TheinputcapacitorshouldbeplacedclosetotheVINandGNDpinsoftheIC,withtheshortesttracespossible.Inthecaseoftantalumorelectrolytictypes,theycanbefurtherawayifasmallparallel1μFceramiccapacitorisplacedrightnexttotheIC.EspeciallyC2capacitorshouldbeplacedascloseaspossibletotheVINpin.OutputCapacitorTheoutputcapacitoralsoneedstohavelowESRtokeeplowoutputvoltageripple.Theoutputripplevoltageis:INRIPPLEOUTRIPPLEESR2OUTVVIKR28fLCSW=+⨯WhereIOUTMAXisthemaximumoutputcurrent,KRIPPLEistheripplefactor,RESRistheESRoftheoutputcapacitor,fSWistheswitchingfrequency,Listheinductorvalue,andCOUTistheoutputcapacitance.Inthecaseofceramicoutputcapacitors,RESRisverysmallanddoesnotcontributetotheripple.Therefore,alowercapacitancevaluecanbeusedforceramictype.Inthecaseoftantalumorelectrolyticcapacitors,therippleisdominatedbyRESRmultipliedbytheripplecurrent.Inthatcase,theoutputcapacitorischosentohavesufficientlylowESR.Forceramicoutputcapacitor,typicallychooseacapacitanceofabout470μF.Fortantalumorelectrolyticcapacitors,chooseacapacitorwithlessthan50mΩESR.PCBLayoutRecommendations1.PCBtrancedefinedasSWnode,whichconnectstotheinductor,shouldbeasshortandwideaspossible.2.InductancebetweentheSWterminalandtheoutputVOUTasfaraspossiblewiththegroundwiretoreducetheoutputsideoftheswitchcoupling.3.ALLsensitiveanalogtracessuchasSENandFBshouldplaceawayfromhigh-voltageswitchingnodesSWnodestoavoidcoupling.4.InputbypasscapacitorshouldbeplacedtotheINpinascloseaspossible.5.FeedbackresistorshouldbeplacedtotheFBpinascloseaspossible.6.GatherthegroundterminalsoftheVINcapacitor(s),VOUTcapacitor(s),andthesourceofthelow-sideMOSFETsascloseaspossible.Signalgroundandpowergroundshouldbeconnectedstronglytogethernearthedevice.7.Thegroundofinputcapacitanceandoutputcapacitanceshouldbeplacedascloseaspossible.PackageInformation（Units:mm）SP1232FWideInputRangeCC/CVSynchronousBuckRegulatorRestrictionsonProductUse◆Si-Poweriscontinuallyworkingtoimprovethequalityandreliabilityofitsproducts.Nevertheless,semiconductordevicesingeneralcanmalfunctionorfailduetotheirinherentelectricalsensitivityandvulnerabilitytophysicalstress.Itistheresponsibilityofthebuyer,whenutilizingSi-Powerproducts,tocomplywiththestandardsofsafetyinmakingasafedesignfortheentiresystem,andtoavoidsituationsinwhichamalfunctionorfailureofsuchSi-Powerproductscouldcauselossofhumanlife,bodilyinjuryordamagetoproperty.◆Indevelopingyourdesigns,pleaseensurethatSi-PowerproductsareusedwithinspecifiedoperatingrangesassetforthinthemostrecentSi-Powerproductsspecifications.◆Theinformationcontainedhereinissubjecttochangewithoutnotice.DBM-DS-0424-120www.si-power.comPage11