LM2576-D

SemiconductorComponentsIndustries,LLC,2002January,2002–Rev.31PublicationOrderNumber:LM2576/DLM25763.0A,15V,Step-DownSwitchingRegulatorTheLM2576seriesofregulatorsaremonolithicintegratedcircuitsideallysuitedforeasyandconvenientdesignofastep–downswitchingregulator(buckconverter).Allcircuitsofthisseriesarecapableofdrivinga3.0Aloadwithexcellentlineandloadregulation.Thesedevicesareavailableinfixedoutputvoltagesof3.3V,5.0V,12V,15V,andanadjustableoutputversion.Theseregulatorsweredesignedtominimizethenumberofexternalcomponentstosimplifythepowersupplydesign.StandardseriesofinductorsoptimizedforusewiththeLM2576areofferedbyseveraldifferentinductormanufacturers.SincetheLM2576converterisaswitch–modepowersupply,itsefficiencyissignificantlyhigherincomparisonwithpopularthree–terminallinearregulators,especiallywithhigherinputvoltages.Inmanycases,thepowerdissipatedissolowthatnoheatsinkisrequiredoritssizecouldbereduceddramatically.AstandardseriesofinductorsoptimizedforusewiththeLM2576areavailablefromseveraldifferentmanufacturers.Thisfeaturegreatlysimplifiesthedesignofswitch–modepowersupplies.TheLM2576featuresincludeaguaranteed±4%toleranceonoutputvoltagewithinspecifiedinputvoltagesandoutputloadconditions,and±10%ontheoscillatorfrequency(±2%over0°Cto125°C).Externalshutdownisincluded,featuring80μA(typical)standbycurrent.Theoutputswitchincludescycle–by–cyclecurrentlimiting,aswellasthermalshutdownforfullprotectionunderfaultconditions.Features•3.3V,5.0V,12V,15V,andAdjustableOutputVersions•AdjustableVersionOutputVoltageRange,1.23to37V±4%MaximumOverLineandLoadConditions•Guaranteed3.0AOutputCurrent•WideInputVoltageRange•RequiresOnly4ExternalComponents•52kHzFixedFrequencyInternalOscillator•TTLShutdownCapability,LowPowerStandbyMode•HighEfficiency•UsesReadilyAvailableStandardInductors•ThermalShutdownandCurrentLimitProtection•MoistureSensitivityLevel(MSL)Equals1Applications•SimpleHigh–EfficiencyStep–Down(Buck)Regulator•EfficientPre–RegulatorforLinearRegulators•On–CardSwitchingRegulators•PositivetoNegativeConverter(Buck–Boost)•NegativeStep–UpConverters•PowerSupplyforBatteryChargers–220TVSUFFIXCASE314B15HeatsinksurfaceconnectedtoPin3TO–220TSUFFIXCASE314DPin1.Vin2.Output3.Ground4.Feedback5.ON/OFFD2PAKD2TSUFFIXCASE936AHeatsinksurface(shownasterminal6incaseoutlinedrawing)isconnectedtoPin3Seegeneralmarkinginformationinthedevicemarkingsectiononpage24ofthisdatasheet.DEVICEMARKINGINFORMATION15LM2576μF3ON/OFF5Output2Feedback4D11N5822Cout1000μFTypicalApplication(FixedOutputVoltageVersions)RepresentativeBlockDiagramandTypicalApplicationUnregulatedDCInput+Vin1CoutFeedback4CinL1D1R2R11.0kOutput2Gnd3ON/OFF5ResetLatchThermalShutdown52kHzOscillator1.235VBand-GapReferenceFreqShift18kHzComparatorFixedGainErrorAmplifierCurrentLimitDriver1.0AmpSwitchON/OFF3.1VInternalRegulatorRegulatedOutputVoutLoadOutputVoltageVersions3.3V5.0V12V15VR2(Ω)1.7k3.1k8.84k11.3kForadjustableversionR1=open,R2=0ΩLM25765.0VRegulatedOutput3.0ALoadThisdevicecontains162activetransistors.ABSOLUTEMAXIMUMRATINGS(AbsoluteMaximumRatingsindicatelimitsbeyondwhichdamagetothedevicemayoccur.)RatingSymbolValueUnitMaximumSupplyVoltageVin45VON/OFFPinInputVoltage––0.3V≤V≤+VinVOutputVoltagetoGround(Steady–State)––1.0VPowerDissipationCase314Band314D(TO–220,5–Lead)PDInternallyLimitedWThermalResistance,Junction–to–AmbientRθJA65°C/WThermalResistance,Junction–to–CaseRθJC5.0°C/WCase936A(D2PAK)PDInternallyLimitedWThermalResistance,Junction–to–AmbientRθJA70°C/WThermalResistance,Junction–to–CaseRθJC5.0°C/WStorageTemperatureRangeTstg–65to+150°CMinimumESDRating(HumanBodyModel:C=100pF,R=1.5kΩ)–2.0kVLeadTemperature(Soldering,10seconds)–260°CMaximumJunctionTemperatureTJ150°CLM2576(OperatingRatingsindicateconditionsforwhichthedeviceisintendedtobefunctional,butdonotguaranteespecificperformancelimits.Forguaranteedspecificationsandtestconditions,seetheElectricalCharacteristics.)RatingSymbolValueUnitOperatingJunctionTemperatureRangeTJ–40to+125°CSupplyVoltageVin40VSYSTEMPARAMETERS([Note1]TestCircuitFigure15)ELECTRICALCHARACTERISTICS(Unlessotherwisespecified,Vin=12Vforthe3.3V,5.0V,andAdjustableversion,Vin=25Vforthe12Vversion,andVin=30Vforthe15Vversion.ILoad=500mA.FortypicalvaluesTJ=25°C,formin/maxvaluesTJistheoperatingjunctiontemperaturerangethatapplies[Note2],unlessotherwisenoted.)CharacteristicsSymbolMinTypMaxUnitLM2576–3.3([Note1]TestCircuitFigure15)OutputVoltage(Vin=12V,ILoad=0.5A,TJ=25°C)Vout3.2343.33.366VOutputVoltage(6.0V≤Vin≤40V,0.5A≤ILoad≤3.0A)VoutVTJ=25°C3.1683.33.432TJ=–40to+125°C3.135–3.465Efficiency(Vin=12V,ILoad=3.0A)η–75–%LM2576–5([Note1]TestCircuitFigure15)OutputVoltage(Vin=12V,ILoad=0.5A,TJ=25°C)Vout4.95.05.1VOutputVoltage(8.0V≤Vin≤40V,0.5A≤ILoad≤3.0A)VoutVTJ=25°C4.85.05.2TJ=–40to+125°C4.75–5.25Efficiency(Vin=12V,ILoad=3.0A)η–77–%LM2576–1