Product Order Technical Tools & Support & Folder Now Documents Software Community LM2576,LM2576HV SNVS107D–JUNE1999–REVISEDMAY2016 ® LM2576xx Series SIMPLE SWITCHER 3-A Step-Down Voltage Regulator 1 Features 3 Description • 3.3-V,5-V,12-V,15-V,andAdjustableOutput The LM2576 series of regulators are monolithic 1 integrated circuits that provide all the active functions Versions for a step-down (buck) switching regulator, capable of • AdjustableVersionOutputVoltageRange,1.23V driving 3-A load with excellent line and load to37V(57VforHVVersion) ±4%MaximumOver regulation.Thesedevicesareavailableinfixedoutput LineandLoadConditions voltages of 3.3 V, 5 V, 12 V, 15 V, and an adjustable • Specified3-AOutputCurrent outputversion. • WideInputVoltageRange:40VUpto60Vfor Requiring a minimum number of external HVVersion components, these regulators are simple to use and • RequiresOnly4ExternalComponents include fault protection and a fixed-frequency oscillator. • 52-kHzFixed-FrequencyInternalOscillator The LM2576 series offers a high-efficiency • TTL-ShutdownCapability,Low-PowerStandby replacement for popular three-terminal linear Mode regulators. It substantially reduces the size of the • HighEfficiency heat sink, and in some cases no heat sink is • UsesReadilyAvailableStandardInductors required. • CreateaCustomDesignwithWEBENCHTools A standard series of inductors optimized for use with • ThermalShutdownandCurrentLimitProtection the LM2576 are available from several different manufacturers. This feature greatly simplifies the 2 Applications designofswitch-modepowersupplies. • SimpleHigh-EfficiencyStep-Down(Buck) Other features include a ±4% tolerance on output Regulator voltage within specified input voltages and output load conditions, and ±10% on the oscillator • EfficientPreregulatorforLinearRegulators frequency. External shutdown is included, featuring • On-CardSwitchingRegulators 50-μA (typical) standby current. The output switch • Positive-to-NegativeConverter(Buck-Boost) includes cycle-by-cycle current limiting, as well as thermal shutdown for full protection under fault conditions. DeviceInformation(1) PARTNUMBER PACKAGE BODYSIZE(NOM) LM2576 TO-220(5) 10.16mm×8.51mm LM2576HV DDPAK/TO-263(5) 10.16mm×8.42mm (1) For all available packages, see the orderable addendum at theendofthedatasheet. FixedOutputVoltageVersionTypicalApplicationDiagram 1 An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectualpropertymattersandotherimportantdisclaimers.PRODUCTIONDATA.

LM2576,LM2576HV SNVS107D–JUNE1999–REVISEDMAY2016 www.ti.com Table of Contents 1 Features.................................................................. 1 7.4 DeviceFunctionalModes........................................14 2 Applications........................................................... 1 8 ApplicationandImplementation........................ 15 3 Description............................................................. 1 8.1 ApplicationInformation............................................15 4 RevisionHistory..................................................... 2 8.2 TypicalApplications................................................19 5 PinConfigurationandFunctions......................... 3 9 PowerSupplyRecommendations...................... 24 6 Specifications......................................................... 4 10 Layout................................................................... 25 6.1 AbsoluteMaximumRatings .....................................4 10.1 LayoutGuidelines.................................................25 6.2 ESDRatings..............................................................4 10.2 LayoutExample....................................................26 6.3 RecommendedOperatingConditions.......................4 10.3 Grounding.............................................................26 6.4 ThermalInformation..................................................4 10.4 HeatSinkandThermalConsiderations................26 6.5 ElectricalCharacteristics:3.3V................................5 11 DeviceandDocumentationSupport................. 28 6.6 ElectricalCharacteristics:5V...................................5 11.1 CustomDesignwithWEBENCHTools.................28 6.7 ElectricalCharacteristics:12V.................................5 11.2 ReceivingNotificationofDocumentationUpdates28 6.8 ElectricalCharacteristics:15V.................................6 11.3 DeviceSupport ....................................................28 6.9 ElectricalCharacteristics:AdjustableOutput 11.4 DocumentationSupport........................................29 Voltage....................................................................... 6 11.5 RelatedLinks........................................................29 6.10 ElectricalCharacteristics:AllOutputVoltage 11.6 CommunityResources..........................................29 Versions.....................................................................6 11.7 Trademarks...........................................................29 6.11 TypicalCharacteristics............................................8 11.8 ElectrostaticDischargeCaution............................29 7 DetailedDescription............................................ 12 11.9 Glossary................................................................30 7.1 Overview.................................................................12 12 Mechanical,Packaging,andOrderable 7.2 FunctionalBlockDiagram.......................................12 Information........................................................... 30 7.3 FeatureDescription.................................................12 4 Revision History NOTE:Pagenumbersforpreviousrevisionsmaydifferfrompagenumbersinthecurrentversion. ChangesfromRevisionC(April2013)toRevisionD Page • AddedESDRatingstable,FeatureDescriptionsection,DeviceFunctionalModes,ApplicationandImplementation section,PowerSupplyRecommendationssection,Layoutsection,DeviceandDocumentationSupportsection,and Mechanical,Packaging,andOrderableInformationsection.................................................................................................. 1 • MovedthethermalresistancedatafromtheElectricalCharacteristics:AllOutputVoltageVersionstabletothe ThermalInformationtable....................................................................................................................................................... 4 ChangesfromRevisionB(April2013)toRevisionC Page • ChangedlayoutofNationalDataSheettoTIformat............................................................................................................. 3 2 SubmitDocumentationFeedback Copyright©1999–2016,TexasInstrumentsIncorporated ProductFolderLinks:LM2576 LM2576HV

LM2576,LM2576HV www.ti.com SNVS107D–JUNE1999–REVISEDMAY2016 5 Pin Configuration and Functions KCPackage 5-PinTO-220 TopView KTTPackage 5-PINDDPAK/TO-263 DDPAK/TO-263(S)Package TopView 5-LeadSurface-MountPackage TopView PinFunctions PIN I/O(1) DESCRIPTION NO. NAME Supplyinputpintocollectorpinofhigh-sidetransistor.Connecttopowersupplyandinput 1 V I bypasscapacitorsCIN.PathfromV pintohighfrequencybypassC andGNDmustbeas IN IN IN shortaspossible. Emitterpinofthepowertransistor.Thisisaswitchingnode.Attachedthispintoaninductor 2 OUTPUT O andthecathodeoftheexternaldiode. 3 GROUND — Groundpin.PathtoC mustbeasshortaspossible. IN Feedbacksenseinputpin.ConnecttothemidpointoffeedbackdividertosetVOUTforADJ 4 FEEDBACK I versionorconnectthispindirectlytotheoutputcapacitorforafixedoutputversion. Enableinputtothevoltageregulator.High=OFFandlow=ON.ConnecttoGNDtoenable 5 ON/OFF I thevoltageregulator.Donotleavethispinfloat. ConnectedtoGND.AttachedtoheatsinkforthermalreliefforTO-220packageorputa — TAB — copperplaneconnectedtothispinasathermalreliefforDDPAKpackage. (1) I=INPUT,O=OUTPUT Copyright©1999–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 3 ProductFolderLinks:LM2576 LM2576HV

LM2576,LM2576HV SNVS107D–JUNE1999–REVISEDMAY2016 www.ti.com 6 Specifications 6.1 Absolute Maximum Ratings overtherecommendedoperatingjunctiontemperaturerangeof-40°Cto125°C(unlessotherwisenoted)(1)(2) MIN MAX UNIT LM2576 45 Maximumsupplyvoltage V LM2576HV 63 ON/OFFpininputvoltage −0.3V≤V≤+V V IN Outputvoltagetoground (Steady-state) −1 V Powerdissipation InternallyLimited Maximumjunctiontemperature,T 150 °C J Storagetemperature,T −65 150 °C stg (1) StressesbeyondthoselistedunderAbsoluteMaximumRatingsmaycausepermanentdamagetothedevice.Thesearestressratings only,whichdonotimplyfunctionaloperationofthedeviceattheseoranyotherconditionsbeyondthoseindicatedunderRecommended OperatingConditions.Exposuretoabsolute-maximum-ratedconditionsforextendedperiodsmayaffectdevicereliability. (2) IfMilitary/Aerospacespecifieddevicesarerequired,pleasecontacttheTISalesOffice/Distributorsforavailabilityandspecifications. 6.2 ESD Ratings VALUE UNIT V Electrostaticdischarge Human-bodymodel(HBM),perANSI/ESDA/JEDECJS-001(1) ±2000 V (ESD) (1) JEDECdocumentJEP155statesthat500-VHBMallowssafemanufacturingwithastandardESDcontrolprocess. 6.3 Recommended Operating Conditions overtherecommendedoperatingjunctiontemperaturerangeof-40°Cto125°C(unlessotherwisenoted) MIN MAX UNIT Temperature LM2576,LM2576HV −40 125 °C LM2576 40 Supplyvoltage V LM2576HV 60 6.4 Thermal Information LM2576,LM2576HV THERMALMETRIC(1)(2)(3) KTT(TO-263) KC(TO-220) UNIT 5PINS 5PINS R Junction-to-ambientthermalresistance 42.6 32.4 °C/W θJA R Junction-to-case(top)thermalresistance 43.3 41.2 °C/W θJC(top) R Junction-to-boardthermalresistance 22.4 17.6 °C/W θJB ψ Junction-to-topcharacterizationparameter 10.7 7.8 °C/W JT ψ Junction-to-boardcharacterizationparameter 21.3 17 °C/W JB R Junction-to-case(bottom)thermalresistance 0.4 0.4 °C/W θJC(bot) (1) Formoreinformationabouttraditionalandnewthermalmetrics,seetheSemiconductorandICPackageThermalMetricsapplication report,SPRA953andtheUsingNewThermalMetricsapplicationsreport,SBVA025. (2) ThepackagethermalimpedanceiscalculatedinaccordancewithJESD51-7 (3) ThermalResistancesweresimulatedona4-layer,JEDECboard. 4 SubmitDocumentationFeedback Copyright©1999–2016,TexasInstrumentsIncorporated ProductFolderLinks:LM2576 LM2576HV

LM2576,LM2576HV www.ti.com SNVS107D–JUNE1999–REVISEDMAY2016 6.5 Electrical Characteristics: 3.3 V SpecificationsareforT =25°C(unlessotherwisenoted). J PARAMETER TESTCONDITIONS MIN TYP MAX UNIT SYSTEMPARAMETERSTESTCIRCUITFigure26andFigure32(1) V =12V,I =0.5A OutputVoltage IN LOAD 3.234 3.3 3.366 V CircuitofFigure26andFigure32 6V≤VIN≤40V,0.5A≤ TJ=25°C 3.168 3.3 3.432 OutputVoltage:LM2576 ILOAD≤3A Appliesoverfull V CircuitofFigure26and operating 3.135 3.465 VOUT Figure32 temperaturerange 6V≤VIN≤60V,0.5A≤ TJ=25°C 3.168 3.3 3.45 OutputVoltage:LM2576HV ILOAD≤3A Appliesoverfull V CircuitofFigure26and operating 3.135 3.482 Figure32 temperaturerange η Efficiency V =12V,I =3A 75% IN LOAD (1) Externalcomponentssuchasthecatchdiode,inductor,inputandoutputcapacitorscanaffectswitchingregulatorsystemperformance. WhentheLM2576/LM2576HVisusedasshowninFigure26andFigure32,systemperformanceisasshowninElectrical Characteristics:AllOutputVoltageVersions. 6.6 Electrical Characteristics: 5 V SpecificationsareforT =25°CfortheFigure26andFigure32(unlessotherwisenoted). J PARAMETER TESTCONDITIONS MIN TYP MAX UNIT SYSTEMPARAMETERSTESTCIRCUITFigure26andFigure32(1) V =12V,I =0.5A V OutputVoltage IN LOAD 4.9 5 5.1 V OUT CircuitofFigure26andFigure32 0.5A≤ILOAD≤3A, TJ=25°C 4.8 5 5.2 V OutputVoltage 8V≤VIN≤40V Appliesoverfull V OUT LM2576 CircuitofFigure26and operating 4.75 5.25 Figure32 temperaturerange 0.5A≤ILOAD≤3A, TJ=25°C 4.8 5 4.75 V OutputVoltage 8V≤VIN≤60V Appliesoverfull V OUT LM2576HV CircuitofFigure26and operating 5.225 5.275 Figure32 temperaturerange η Efficiency V =12V,I =3A 77% IN LOAD (1) Externalcomponentssuchasthecatchdiode,inductor,inputandoutputcapacitorscanaffectswitchingregulatorsystemperformance. WhentheLM2576/LM2576HVisusedasshowninFigure26andFigure32,systemperformanceisasshowninElectrical Characteristics:AllOutputVoltageVersions. 6.7 Electrical Characteristics: 12 V SpecificationsareforT =25°C(unlessotherwisenoted). J PARAMETER TESTCONDITIONS MIN TYP MAX UNIT SYSTEMPARAMETERSTESTCIRCUITFigure26andFigure32(1) V =25V,I =0.5A V OutputVoltage IN LOAD 11.76 12 12.24 V OUT CircuitofFigure26andFigure32 0.5A≤ILOAD≤3A, TJ=25°C 11.52 12 12.48 V OutputVoltage 15V≤VIN≤40V Appliesoverfull V OUT LM2576 CircuitofFigure26and operating 11.4 12.6 Figure32and temperaturerange 0.5A≤ILOAD≤3A, TJ=25°C 11.52 12 12.54 V OutputVoltage 15V≤VIN≤60V Appliesoverfull V OUT LM2576HV CircuitofFigure26and operating 11.4 12.66 Figure32 temperaturerange η Efficiency V =15V,I =3A 88% IN LOAD (1) Externalcomponentssuchasthecatchdiode,inductor,inputandoutputcapacitorscanaffectswitchingregulatorsystemperformance. WhentheLM2576/LM2576HVisusedasshowninFigure26andFigure32,systemperformanceisasshowninElectrical Characteristics:AllOutputVoltageVersions. Copyright©1999–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 5 ProductFolderLinks:LM2576 LM2576HV

LM2576,LM2576HV SNVS107D–JUNE1999–REVISEDMAY2016 www.ti.com 6.8 Electrical Characteristics: 15 V overoperatingfree-airtemperaturerange(unlessotherwisenoted). PARAMETER TESTCONDITIONS MIN TYP MAX UNIT SYSTEMPARAMETERSTESTCIRCUITFigure26andFigure32(1) V =25V,I =0.5A V OutputVoltage IN LOAD 14.7 15 15.3 V OUT CircuitofFigure26andFigure32 0.5A≤ILOAD≤3A, TJ=25°C 14.4 15 15.6 V OutputVoltage 18V≤VIN≤40V Appliesoverfull V OUT LM2576 CircuitofFigure26and operating 14.25 15.75 Figure32 temperaturerange 0.5A≤ILOAD≤3A, TJ=25°C 14.4 15 14.25 V OutputVoltage 18V≤VIN≤60V Appliesoverfull V OUT LM2576HV CircuitofFigure26and operating 15.68 15.83 Figure32 temperaturerange η Efficiency V =18V,I =3A 88% IN LOAD (1) Externalcomponentssuchasthecatchdiode,inductor,inputandoutputcapacitorscanaffectswitchingregulatorsystemperformance. WhentheLM2576/LM2576HVisusedasshowninFigure26andFigure32,systemperformanceisasshowninElectrical Characteristics:AllOutputVoltageVersions. 6.9 Electrical Characteristics: Adjustable Output Voltage overoperatingfree-airtemperaturerange(unlessotherwisenoted). PARAMETER TESTCONDITIONS MIN TYP MAX UNIT SYSTEMPARAMETERSTESTCIRCUITFigure26andFigure32(1) V =12V,I =0.5A IN LOAD V Feedbackvoltage V =5V, 1.217 1.23 1.243 V OUT OUT CircuitofFigure26andFigure32 0.5A≤ILOAD≤3A, TJ=25°C 1.193 1.23 1.267 V FeedbackVoltage 8V≤VIN≤40V Appliesoverfull V OUT LM2576 VOUT=5V,Circuitof operating 1.18 1.28 Figure26andFigure32 temperaturerange 0.5A≤ILOAD≤3A, TJ=25°C 1.193 1.23 1.273 V FeedbackVoltage 8V≤VIN≤60V Appliesoverfull V OUT LM2576HV VOUT=5V,Circuitof operating 1.18 1.286 Figure26andFigure32 temperaturerange η Efficiency V =12V,I =3A,V =5V 77% IN LOAD OUT (1) Externalcomponentssuchasthecatchdiode,inductor,inputandoutputcapacitorscanaffectswitchingregulatorsystemperformance. WhentheLM2576/LM2576HVisusedasshowninFigure26andFigure32,systemperformanceisasshowninElectrical Characteristics:AllOutputVoltageVersions. 6.10 Electrical Characteristics: All Output Voltage Versions overoperatingfree-airtemperaturerange(unlessotherwisenoted) PARAMETER TESTCONDITIONS MIN TYP(1) MAX UNIT SYSTEMPARAMETERSTESTCIRCUITFigure26andFigure32(2) T =25°C 100 50 J I FeedbackBiasCurrent VOUT=5V(Adjustable Appliesoverfull nA b VersionOnly) operating 500 temperaturerange T =25°C 47 52 58 f OscillatorFrequency(3) J kHz O Appliesoverfulloperatingtemperaturerange 42 63 (1) Alllimitsspecifiedatroomtemperature(25°C)unlessotherwisenoted.Allroomtemperaturelimitsare100%productiontested.Alllimits attemperatureextremesarespecifiedthroughcorrelationusingstandardStatisticalQualityControl(SQC)methods. (2) Externalcomponentssuchasthecatchdiode,inductor,inputandoutputcapacitorscanaffectswitchingregulatorsystemperformance. WhentheLM2576/LM2576HVisusedasshowninFigure26andFigure32,systemperformanceisasshowninElectrical Characteristics:AllOutputVoltageVersions. (3) Theoscillatorfrequencyreducestoapproximately11kHzintheeventofanoutputshortoranoverloadwhichcausestheregulated outputvoltagetodropapproximately40%fromthenominaloutputvoltage.Thisselfprotectionfeaturelowerstheaveragepower dissipationoftheICbyloweringtheminimumdutycyclefrom5%downtoapproximately2%. 6 SubmitDocumentationFeedback Copyright©1999–2016,TexasInstrumentsIncorporated ProductFolderLinks:LM2576 LM2576HV

LM2576,LM2576HV www.ti.com SNVS107D–JUNE1999–REVISEDMAY2016 Electrical Characteristics: All Output Voltage Versions (continued) overoperatingfree-airtemperaturerange(unlessotherwisenoted) PARAMETER TESTCONDITIONS MIN TYP(1) MAX UNIT T =25°C 1.4 1.8 J V SaturationVoltage I =3A (4) Appliesoverfull V SAT OUT operating 2 temperaturerange DC MaxDutyCycle(ON)(5) 93% 98% T =25°C 4.2 5.8 6.9 I CurrentLimit(4)(3) J A CL Appliesoverfulloperatingtemperaturerange 3.5 7.5 Output=0V I OutputLeakageCurrent Output=−1V 2 7.5 30 mA L Output=−1V (6)(7) I QuiescentCurrent(6) 5 10 mA Q StandbyQuiescent I ON/OFFPin=5V(OFF) 50 200 μA STBY Current ON/OFFCONTROLTESTCIRCUITFigure26andFigure32 V =0V T =25°C 2.2 1.4 OUT J V Appliesoverfull V IH operating 2.4 ON/OFFPin temperaturerange LogicInputLevel V =NominalOutput T =25°C 1.2 1 OUT J Voltage V Appliesoverfull V IL operating 0.8 temperaturerange IIH ON/OFFPinInput ON/OFFPin=5V(OFF) 12 30 μA I Current ON/OFFPin=0V(ON) 0 10 μA IL (4) Outputpinsourcingcurrent.Nodiode,inductororcapacitorconnectedtooutput. (5) Feedbackpinremovedfromoutputandconnectedto0V. (6) Feedbackpinremovedfromoutputandconnectedto+12VfortheAdjustable,3.3-V,and5-Vversions,and+25Vforthe12-Vand15- Vversions,toforcetheoutputtransistorOFF. (7) V =40V(60Vforhighvoltageversion). IN Copyright©1999–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 7 ProductFolderLinks:LM2576 LM2576HV

LM2576,LM2576HV SNVS107D–JUNE1999–REVISEDMAY2016 www.ti.com 6.11 Typical Characteristics (CircuitofFigure26andFigure32) Figure1.NormalizedOutputVoltage Figure2.LineRegulation Figure3.DropoutVoltage Figure4.CurrentLimit Figure5.QuiescentCurrent Figure6.StandbyQuiescentCurrent 8 SubmitDocumentationFeedback Copyright©1999–2016,TexasInstrumentsIncorporated ProductFolderLinks:LM2576 LM2576HV

LM2576,LM2576HV www.ti.com SNVS107D–JUNE1999–REVISEDMAY2016 Typical Characteristics (continued) (CircuitofFigure26andFigure32) Figure7.OscillatorFrequency Figure8.SwitchSaturationVoltage Figure10.MinimumOperatingVoltage Figure9.Efficiency Figure11.QuiescentCurrentvsDutyCycle Figure12.FeedbackVoltagevsDutyCycle Copyright©1999–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 9 ProductFolderLinks:LM2576 LM2576HV

LM2576,LM2576HV SNVS107D–JUNE1999–REVISEDMAY2016 www.ti.com Typical Characteristics (continued) (CircuitofFigure26andFigure32) Figure13.MinimumOperatingVoltage Figure14.QuiescentCurrentvsDutyCycle Figure15.FeedbackVoltagevsDutyCycle Figure16.FeedbackPinCurrent V =15V OUT A:OutputPinVoltage,50V/div B:OutputPinCurrent,2A/div IftheDDPAK/TO-263packageisused,thethermalresistancecanbe C:InductorCurrent,2A/div reducedbyincreasingthePCBcopperareathermallyconnectedto D:OutputRippleVoltage,50mV/div, thepackage.Using0.5squareinchesofcopperarea,θ is50°C/W, JA AC-Coupled with1squareinchofcopperarea,θ is37°C/W,andwith1.6or JA moresquareinchesofcopperarea,θ is32°C/W. HorizontalTimeBase:5μs/div JA Figure17.MaximumPowerDissipation(DDPAK/TO-263) Figure18.SwitchingWaveforms 10 SubmitDocumentationFeedback Copyright©1999–2016,TexasInstrumentsIncorporated ProductFolderLinks:LM2576 LM2576HV

LM2576,LM2576HV www.ti.com SNVS107D–JUNE1999–REVISEDMAY2016 Typical Characteristics (continued) (CircuitofFigure26andFigure32) Figure19.LoadTransientResponse Copyright©1999–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 11 ProductFolderLinks:LM2576 LM2576HV

LM2576,LM2576HV SNVS107D–JUNE1999–REVISEDMAY2016 www.ti.com 7 Detailed Description 7.1 Overview The LM2576 SIMPLE SWITCHER® regulator is an easy-to-use, non-synchronous step-down DC-DC converter with a wide input voltage range from 40 V to up to 60 V for a HV version. It is capable of delivering up to 3-A DC load current with excellent line and load regulation. These devices are available in fixed output voltages of 3.3 V, 5 V, 12 V, 15 V, and an adjustable output version. The family requires few external components, and the pin arrangementwasdesignedforsimple,optimumPCBlayout. 7.2 Functional Block Diagram 3.3VR2=1.7k 5V,R2=3.1k 12V,R2=8.84k 15V,R2=11.3k ForADJ.Version R1=Open,R2=0Ω PatentPending 7.3 Feature Description 7.3.1 UndervoltageLockout In some applications it is desirable to keep the regulator off until the input voltage reaches a certain threshold. Figure 20 shows an undervoltage lockout circuit that accomplishes this task, while Figure 21 shows the same circuit applied to a buck-boost configuration. These circuits keep the regulator off until the input voltage reaches apredeterminedlevel. V ≈V +2V (Q1) (1) TH Z1 BE 12 SubmitDocumentationFeedback Copyright©1999–2016,TexasInstrumentsIncorporated ProductFolderLinks:LM2576 LM2576HV

LM2576,LM2576HV www.ti.com SNVS107D–JUNE1999–REVISEDMAY2016 Feature Description (continued) Completecircuitnotshown. Figure20. UndervoltageLockoutforBuckCircuit Completecircuitnotshown(seeFigure24). Figure21. UndervoltageLockout forBuck-BoostCircuit 7.3.2 DelayedStart-Up The ON /OFF pin can be used to provide a delayed start-up feature as shown in Figure 22. With an input voltage of 20 V and for the part values shown, the circuit provides approximately 10 ms of delay time before the circuit begins switching. Increasing the RC time constant can provide longer delay times. But excessively large RC time constants can cause problems with input voltages that are high in 60-Hz or 120-Hz ripple, by coupling the ripple intotheON /OFFpin. 7.3.3 AdjustableOutput,Low-RipplePowerSupply Figure 23 shows a 3-A power supply that features an adjustable output voltage. An additional LC filter that reducestheoutputripplebyafactorof10ormoreisincludedinthiscircuit. Copyright©1999–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 13 ProductFolderLinks:LM2576 LM2576HV

LM2576,LM2576HV SNVS107D–JUNE1999–REVISEDMAY2016 www.ti.com Feature Description (continued) Completecircuitnotshown. Figure22. DelayedStart-Up Figure23. 1.2-Vto55-VAdjustable3-APowerSupplyWithLowOutputRipple 7.4 Device Functional Modes 7.4.1 ShutdownMode The ON/OFF pin provides electrical ON and OFF control for the LM2576. When the voltage of this pin is higher than1.4V,thedeviceisinshutdownmode.Thetypicalstandbycurrentinthismodeis50 μA. 7.4.2 ActiveMode Whenthevoltageofthe ON/OFFpinisbelow1.2V,thedevicestartsswitching,andtheoutputvoltagerisesuntil itreachesthenormalregulationvoltage. 7.4.3 CurrentLimit The LM2576 device has current limiting to prevent the switch current from exceeding safe values during an accidental overload on the output. This current limit value can be found in Electrical Characteristics: All Output VoltageVersions undertheheadingofI . CL The LM2576 uses cycle-by-cycle peak current limit for overload protection. This helps to prevent damage to the device and external components. The regulator operates in current limit mode whenever the inductor current exceeds the value of I given in Electrical Characteristics: All Output Voltage Versions. This occurs if the load CL current is greater than 3 A, or the converter is starting up. Keep in mind that the maximum available load current depends on the input voltage, output voltage, and inductor value. The regulator also incorporates short-circuit protection to prevent inductor current run-away. When the voltage on the FB pin (ADJ) falls below about 0.58 V the switching frequency is dropped to about 11 kHz. This allows the inductor current to ramp down sufficiently duringtheswitchOFF-timetopreventsaturation. 14 SubmitDocumentationFeedback Copyright©1999–2016,TexasInstrumentsIncorporated ProductFolderLinks:LM2576 LM2576HV

LM2576,LM2576HV www.ti.com SNVS107D–JUNE1999–REVISEDMAY2016 8 Application and Implementation NOTE Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validateandtesttheirdesignimplementationtoconfirmsystemfunctionality. 8.1 Application Information 8.1.1 InputCapacitor(C ) IN To maintain stability, the regulator input pin must be bypassed with at least a 100-μF electrolytic capacitor. The capacitor'sleadsmustbekeptshort,andplacedneartheregulator. If the operating temperature range includes temperatures below −25°C, the input capacitor value may need to be larger. With most electrolytic capacitors, the capacitance value decreases and the ESR increases with lower temperatures and age. Paralleling a ceramic or solid tantalum capacitor increases the regulator stability at cold temperatures. For maximum capacitor operating lifetime, the RMS ripple current rating of the capacitor must be greaterthan: (2) 8.1.2 InductorSelection All switching regulators have two basic modes of operation: continuous and discontinuous. The difference betweenthetwotypesrelatestotheinductorcurrent,whetheritisflowingcontinuously,orifitdropstozerofora period of time in the normal switching cycle. Each mode has distinctively different operating characteristics, whichcanaffecttheregulatorperformanceandrequirements. The LM2576 (or any of the SIMPLE SWITCHER® family can be used for both continuous and discontinuous modesofoperation. The inductor value selection guides in Figure 27 through Figure 31 are designed for buck regulator designs of the continuous inductor current type. When using inductor values shown in the inductor selection guide, the peak-to-peak inductor ripple current is approximately 20% to 30% of the maximum DC current. With relatively heavy load currents, the circuit operates in the continuous mode (inductor current always flowing), but under light load conditions, the circuit is forced to the discontinuous mode (inductor current falls to zero for a period of time). This discontinuous mode of operation is perfectly acceptable. For light loads (less than approximately 300 mA), it may be desirable to operate the regulator in the discontinuous mode, primarily because of the lower inductor valuesrequiredforthediscontinuousmode. The selection guide chooses inductor values suitable for continuous mode operation, but if the inductor value chosenisprohibitivelyhigh,thedesignershouldinvestigatethepossibilityofdiscontinuousoperation. Inductors are available in different styles such as pot core, toriod, E-frame, bobbin core, and so on, as well as different core materials, such as ferrites and powdered iron. The bobbin core is the least expensive type, and consists of wire wrapped on a ferrite rod core. This type of construction makes for an inexpensive inductor; however, because the magnetic flux is not completely contained within the core, the bobbin core generates more electromagnetic interference (EMI). This EMI can cause problems in sensitive circuits, or can give incorrect scopereadingsbecauseofinducedvoltagesinthescopeprobe. The inductors listed in the selection chart include ferrite pot core construction for AIE, powdered iron toroid for PulseEngineering,andferritebobbincoreforRenco. Copyright©1999–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 15 ProductFolderLinks:LM2576 LM2576HV

LM2576,LM2576HV SNVS107D–JUNE1999–REVISEDMAY2016 www.ti.com Application Information (continued) An inductor must not operate beyond its maximum-rated current because it may saturate. When an inductor begins to saturate, the inductance decreases rapidly, and the inductor begins to look mainly resistive (the DC resistance of the winding), causing the switch current to rise very rapidly. Different inductor types have different saturationcharacteristics,andthismustbeconsideredwhenselectinganinductor. Theinductormanufacturer'sdatasheetsincludecurrentandenergylimitstoavoidinductorsaturation. 8.1.3 InductorRippleCurrent When the switcher is operating in the continuous mode, the inductor current waveform ranges from a triangular to a sawtooth type of waveform (depending on the input voltage). For a given input voltage and output voltage, the peak-to-peak amplitude of this inductor current waveform remains constant. As the load current rises or falls, the entire sawtooth current waveform also rises or falls. The average DC value of this waveform is equal to the DCloadcurrent(inthebuckregulatorconfiguration). If the load current drops to a low enough level, the bottom of the sawtooth current waveform reaches zero, and the switcher changes to a discontinuous mode of operation. This is a perfectly acceptable mode of operation. Any buck switching regulator (no matter how large the inductor value is) is forced to run discontinuous if the load currentislightenough. 8.1.4 OutputCapacitor An output capacitor is required to filter the output voltage and is needed for loop stability. The capacitor must be placed near the LM2576 using short PCB traces. Standard aluminum electrolytics are usually adequate, but TI recommends low ESR types for low output ripple voltage and good stability. The ESR of a capacitor depends on many factors, including: the value, the voltage rating, physical size, and the type of construction. In general, low valueorlowvoltage(lessthan12V)electrolyticcapacitorsusuallyhavehigherESRnumbers. The amount of output ripple voltage is primarily a function of the ESR (Equivalent Series Resistance) of the outputcapacitorandtheamplitudeoftheinductorripplecurrent(ΔI ).SeeInductorRippleCurrent. IND The lower capacitor values (220 μF to 1000 μF) allows typically 50 mV to 150 mV of output ripple voltage, while larger-valuecapacitorsreducestherippletoapproximately20mVto50mV. OutputRippleVoltage=(ΔI )(ESRofC ) (3) IND OUT To further reduce the output ripple voltage, several standard electrolytic capacitors may be paralleled, or a higher-grade capacitor may be used. Such capacitors are often called high-frequency, low-inductance, or low- ESR. These reduces the output ripple to 10 mV or 20 mV. However, when operating in the continuous mode, reducingtheESRbelow0.03Ω cancauseinstabilityintheregulator. Tantalum capacitors can have a very low ESR, and must be carefully evaluated if it is the only output capacitor. Because of their good low temperature characteristics, a tantalum can be used in parallel with aluminum electrolytics,withthetantalummakingup10%or20%ofthetotalcapacitance. The ripple current rating of the capacitor at 52 kHz should be at least 50% higher than the peak-to-peak inductor ripplecurrent. 8.1.5 CatchDiode Buckregulatorsrequireadiodetoprovideareturnpathfortheinductorcurrentwhentheswitchisoff.Thisdiode mustbeplacedclosetotheLM2576usingshortleadsandshortprinted-circuittraces. Because of their fast switching speed and low forward voltage drop, Schottky diodes provide the best efficiency, especially in low output voltage switching regulators (less than 5 V). Fast-recovery, high-efficiency, or ultra-fast recovery diodes are also suitable, but some types with an abrupt turnoff characteristic may cause instability and EMI problems. A fast-recovery diode with soft recovery characteristics is a better choice. Standard 60-Hz diodes (for example, 1N4001 or 1N5400, and so on) are also not suitable. See Table 3 for Schottky and soft fast- recoverydiodeselectionguide. 16 SubmitDocumentationFeedback Copyright©1999–2016,TexasInstrumentsIncorporated ProductFolderLinks:LM2576 LM2576HV

LM2576,LM2576HV www.ti.com SNVS107D–JUNE1999–REVISEDMAY2016 Application Information (continued) 8.1.6 OutputVoltageRippleandTransients The output voltage of a switching power supply contains a sawtooth ripple voltage at the switcher frequency, typically about 1% of the output voltage, and may also contain short voltage spikes at the peaks of the sawtooth waveform. TheoutputripplevoltageisduemainlytotheinductorsawtoothripplecurrentmultipliedbytheESRoftheoutput capacitor(seeInductorSelection). The voltage spikes are present because of the fast switching action of the output switch, and the parasitic inductance of the output filter capacitor. To minimize these voltage spikes, special low inductance capacitors can be used, and their lead lengths must be kept short. Wiring inductance, stray capacitance, as well as the scope probeusedtoevaluatethesetransients,allcontributetotheamplitudeofthesespikes. An additional small LC filter (20 μH and 100 μF) can be added to the output (as shown in Figure 23) to further reduce the amount of output ripple and transients. A 10 × reduction in output ripple voltage and transients is possiblewiththisfilter. 8.1.7 FeedbackConnection The LM2576 (fixed voltage versions) feedback pin must be wired to the output voltage point of the switching power supply. When using the adjustable version, physically locate both output voltage programming resistors near the LM2576 to avoid picking up unwanted noise. Avoid using resistors greater than 100 kΩ because of the increasedchanceofnoisepickup. 8.1.8 ON /OFFINPUT For normal operation, the ON /OFF pin must be grounded or driven with a low-level TTL voltage (typically below 1.6 V). To put the regulator into standby mode, drive this pin with a high-level TTL or CMOS signal. The ON /OFF pin can be safely pulled up to +V without a resistor in series with it. The ON /OFF pin must not be left IN open. 8.1.9 InvertingRegulator Figure 24 shows a LM2576-12 in a buck-boost configuration to generate a negative 12-V output from a positive input voltage. This circuit bootstraps the ground pin of the regulator to the negative output voltage, then by groundingthefeedbackpin,theregulatorsensestheinvertedoutputvoltageandregulatesitto −12V. For an input voltage of 12 V or more, the maximum available output current in this configuration is approximately 700mA.Atlighterloads,theminimuminputvoltagerequireddropstoapproximately4.7V. The switch currents in this buck-boost configuration are higher than in the standard buck-mode design, thus lowering the available output current. Also, the start-up input current of the buck-boost converter is higher than thestandardbuck-moderegulator,andthismayoverloadaninputpowersourcewithacurrentlimitlessthan 5 A. Using a delayed turn-on or an undervoltage lockout circuit (described in Negative Boost Regulator) would allowtheinputvoltagetorisetoahighenoughlevelbeforetheswitcherwouldbeallowedtoturnon. Because of the structural differences between the buck and the buck-boost regulator topologies, the buck regulator design procedure section can not be used to select the inductor or the output capacitor. The recommended range of inductor values for the buck-boost design is between 68 μH and 220 μH, and the output capacitor values must be larger than what is normally required for buck designs. Low input voltages or high outputcurrentsrequirealargevalueoutputcapacitor(inthethousandsofmicroFarads). Thepeakinductorcurrent,whichisthesameasthepeakswitchcurrent,canbecalculatedinEquation4: where • f =52kHz (4) osc Under normal continuous inductor current operating conditions, the minimum V represents the worst case. IN Selectaninductorthatisratedforthepeakcurrentanticipated. Copyright©1999–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 17 ProductFolderLinks:LM2576 LM2576HV

LM2576,LM2576HV SNVS107D–JUNE1999–REVISEDMAY2016 www.ti.com Application Information (continued) Figure24. InvertingBuck-BoostDevelops −12V Also, the maximum voltage appearing across the regulator is the absolute sum of the input and output voltage. Fora−12-Voutput,themaximuminputvoltagefortheLM2576is+28V,or+48VfortheLM2576HV. 8.1.10 NegativeBoostRegulator Another variation on the buck-boost topology is the negative boost configuration. The circuit in Figure 25 accepts an input voltage ranging from −5 V to −12 V and provides a regulated −12-V output. Input voltages greater than −12Vcausestheoutputtoriseabove −12V,butdoesnotdamagetheregulator. Feedback + COUT VIN 4 2200 PF LM2576-12 Output 1 LOW ESR 2 3 5 1N5820 + CIN GND ON/OFF 100 PF VOUT = -12V -VIN 100 PH -5V to -12V Copyright © 2016, Texas Instruments Incorporated TypicalLoadCurrent 400mAforV =−5.2V IN 750mAforV =−7V IN Heatsinkmayberequired. Figure25. NegativeBoost Because of the boosting function of this type of regulator, the switch current is relatively high, especially at low input voltages. Output load current limitations are a result of the maximum current rating of the switch. Also, boost regulators can not provide current-limiting load protection in the event of a shorted load, so some other means(suchasafuse)maybenecessary. 18 SubmitDocumentationFeedback Copyright©1999–2016,TexasInstrumentsIncorporated ProductFolderLinks:LM2576 LM2576HV

LM2576,LM2576HV www.ti.com SNVS107D–JUNE1999–REVISEDMAY2016 8.2 Typical Applications 8.2.1 FixedOutputVoltageVersion C —100-μF,75-V,AluminumElectrolytic IN C —1000-μF,25-V,AluminumElectrolytic OUT D —Schottky,MBR360 1 L —100μH,PulseEng.PE-92108 1 R —2k,0.1% 1 R —6.12k,0.1% 2 Figure26. FixedOutputVoltageVersions 8.2.1.1 DesignRequirements Table1liststhedesignparametersofthisexample. Table1.DesignParameters DESIGNPARAMETER EXAMPLEVALUE RegulatedOutputVoltage 5V (3.3V,5V,12V,or15V),V OUT MaximumInputVoltage,V (Max) 15V IN MaximumLoadCurrent, 3A I (Max) LOAD 8.2.1.2 DetailedDesignProcedure 8.2.1.2.1 CustomDesignwithWEBENCHTools ClickheretocreateacustomdesignusingtheWEBENCH® PowerDesigner. 1. StartbyenteringyourV ,V andI requirements. IN OUT OUT 2. Optimize your design for key parameters like efficiency, footprint and cost using the optimizer dial and comparethisdesignwithotherpossiblesolutionsfromTexasInstruments. 3. WEBENCH Power Designer provides you with a customized schematic along with a list of materials with real timepricingandcomponentavailability. 4. Inmostcases,youwillalsobeableto: – Runelectricalsimulationstoseeimportantwaveformsandcircuitperformance, – Runthermalsimulationstounderstandthethermalperformanceofyourboard, – ExportyourcustomizedschematicandlayoutintopopularCADformats, – PrintPDFreportsforthedesign,andshareyourdesignwithcolleagues. 8.2.1.2.2 InductorSelection(L1) 1. Select the correct Inductor value selection guide from Figure 27, Figure 28, Figure 29, or Figure 30. (Output voltagesof3.3V,5V,12Vor15Vrespectively).Forotheroutputvoltages,seethedesignprocedureforthe Copyright©1999–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 19 ProductFolderLinks:LM2576 LM2576HV

LM2576,LM2576HV SNVS107D–JUNE1999–REVISEDMAY2016 www.ti.com adjustableversion.UsetheselectionguideshowninFigure28. 2. From the inductor value selection guide, identify the inductance region intersected by V (Max) and IN I (Max), and note the inductor code for that region. From the selection guide, the inductance area LOAD intersectedbythe15-Vlineand3-AlineisL100. 3. Identify the inductor value from the inductor code, and select an appropriate inductor from the table shown in Figure 27. Part numbers are listed for three inductor manufacturers. The inductor chosen must be rated for operation at the LM2576 switching frequency (52 kHz) and for a current rating of 1.15 × I . For additional LOAD inductor information, see Inductor Selection. Inductor value required is 100 μH from the table in Figure 27. ChooseAIE415-0930,PulseEngineeringPE92108,orRencoRL2444. 8.2.1.2.3 OutputCapacitorSelection(C ) OUT 1. The value of the output capacitor together with the inductor defines the dominate pole-pair of the switching regulator loop. For stable operation and an acceptable output ripple voltage, (approximately 1% of the output voltage) TI recommends a value between 100 μF and 470 μF. We choose C = 680-μF to 2000-μF OUT standardaluminumelectrolytic. 2. The voltage rating of the capacitor must be at least 1.5 times greater than the output voltage. For a 5-V regulator, a rating of at least 8 V is appropriate, and a 10-V or 15-V rating is recommended. Capacitor voltage rating = 20 V. Higher voltage electrolytic capacitors generally have lower ESR numbers, and for this reasonitmaybenecessarytoselectacapacitorratedforahighervoltagethanwouldnormallybeneeded. 8.2.1.2.4 CatchDiodeSelection(D1) 1. The catch-diode current rating must be at least 1.2 times greater than the maximum load current. Also, if the power supply design must withstand a continuous output short, the diode should have a current rating equal to the maximum current limit of the LM2576. The most stressful condition for this diode is an overload or shortedoutputcondition.Forthisexample,a3-Acurrentratingisadequate. 2. The reverse voltage rating of the diode should be at least 1.25 times the maximum input voltage. Use a 20-V 1N5823orSR302Schottkydiode,oranyofthesuggestedfast-recoverydiodesshowninTable3. 8.2.1.2.5 InputCapacitor(C ) IN An aluminum or tantalum electrolytic bypass capacitor located close to the regulator is needed for stable operation. A 100-μF, 25-V aluminum electrolytic capacitor located near the input and ground pins provides sufficientbypassing. 8.2.1.3 ApplicationCurves Figure27.LM2576(HV)-3.3 Figure28.LM2576(HV)-5.0 20 SubmitDocumentationFeedback Copyright©1999–2016,TexasInstrumentsIncorporated ProductFolderLinks:LM2576 LM2576HV

LM2576,LM2576HV www.ti.com SNVS107D–JUNE1999–REVISEDMAY2016 Figure29.LM2576(HV)-12 Figure30.LM2576(HV)-15 Figure31.LM2576(HV)-ADJ Copyright©1999–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 21 ProductFolderLinks:LM2576 LM2576HV

LM2576,LM2576HV SNVS107D–JUNE1999–REVISEDMAY2016 www.ti.com 8.2.2 AdjustedOutputVoltageVersion where V =1.23V,R1between1kand5k REF Figure32. AdjustableOutputVoltageVersion 8.2.2.1 DesignRequirements Table2liststhedesignparametersofthisexample. Table2.DesignParameters DESIGNPARAMETER EXAMPLEVALUE RegulatedOutputVoltage,V 10V OUT MaximumInputVoltage,V (Max) 25V IN MaximumLoadCurrent, 3A I (Max) LOAD SwitchingFrequency,F Fixedat52kHz 8.2.2.2 DetailedDesignProcedure 8.2.2.2.1 ProgrammingOutputVoltage SelectR1andR2,asshowninFigure32. UseEquation5toselecttheappropriateresistorvalues. (5) R can be between 1k and 5k. (For best temperature coefficient and stability with time, use 1% metal film 1 resistors) (6) (7) R =1k(8.13− 1)=7.13k,closest1%valueis7.15k 2 8.2.2.2.2 InductorSelection(L1) 1. CalculatetheinductorVolt•microsecondconstant,E •T(V •μs),fromEquation8: 22 SubmitDocumentationFeedback Copyright©1999–2016,TexasInstrumentsIncorporated ProductFolderLinks:LM2576 LM2576HV

LM2576,LM2576HV www.ti.com SNVS107D–JUNE1999–REVISEDMAY2016 (8) CalculateE•T(V •μs) (9) 2. Use the E • T value from the previous formula and match it with the E • T number on the vertical axis of the InductorvalueselectionguideshowninFigure31. E•T=115V •μs 3. Onthehorizontalaxis,selectthemaximumloadcurrent. I (Max)=3A LOAD 4. Identify the inductance region intersected by the E • T value and the maximum load current value, and note theinductorcodeforthatregion. InductanceRegion=H150 5. Identify the inductor value from the inductor code, and select an appropriate inductor from the table shown in Table 4. Part numbers are listed for three inductor manufacturers. The inductor chosen must be rated for operation at the LM2576 switching frequency (52 kHz) and for a current rating of 1.15 × I . For additional LOAD inductorinformation,seeInductorSelection. InductorValue=150 μH ChoosefromAIEpart#415-0936,PulseEngineeringpart#PE-531115,or Rencopart#RL2445. 8.2.2.2.3 OutputCapacitorSelection(C ) OUT 1. The value of the output capacitor together with the inductor defines the dominate pole-pair of the switching regulatorloop.Forstableoperation,thecapacitormustsatisfy: yields capacitor values between 10 μF and 2200 μF that satisfies the loop requirements for stable operation. But to achieve an acceptable output ripple voltage, (approximately 1% of the output voltage) and transient response,theoutputcapacitormayneedtobeseveraltimeslargerthanyields. However,foracceptableoutputripplevoltageselect C ≥680 μF OUT C =680-μFelectrolyticcapacitor OUT 2. The capacitor's voltage rating must be at last 1.5 times greater than the output voltage. For a 10-V regulator, a rating of at least 15 V or more is recommended. Higher voltage electrolytic capacitors generally have lower ESR numbers, and for this reason it may be necessary to select a capacitor rate for a higher voltage than wouldnormallybeneeded. 8.2.2.2.4 CatchDiodeSelection(D1) 1. The catch-diode current rating must be at least 1.2 times greater than the maximum load current. Also, if the power supply design must withstand a continuous output short, the diode must have a current rating equal to the maximum current limit of the LM2576. The most stressful condition for this diode is an overload or shortedoutput.SeeTable3.Forthisexample,a3.3-Acurrentratingisadequate. 2. The reverse voltage rating of the diode should be at least 1.25 times the maximum input voltage. Use a 30-V 31DQ03Schottkydiode,oranyofthesuggestedfast-recoverydiodesinTable3. 8.2.2.2.5 InputCapacitor(C ) IN An aluminum or tantalum electrolytic bypass capacitor located close to the regulator is needed for stable operation. A 100-μF aluminum electrolytic capacitor located near the input and ground pins provides sufficient bypassing. Copyright©1999–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 23 ProductFolderLinks:LM2576 LM2576HV

LM2576,LM2576HV SNVS107D–JUNE1999–REVISEDMAY2016 www.ti.com Table3.DiodeSelectionGuide SCHOTTKY FASTRECOVERY V R 3A 4Ato6A 3A 4Ato6A 1N5820 20V MBR320P 1N5823 SR302 1N5821 MBR330 50WQ03 30V 31DQ03 1N5824 SR303 Thefollowing Thefollowing 1N5822 diodesareall diodesareall MBR340 ratedto100-V MBR340 ratedto100-V 40V 50WQ04 31DF1 50WF10 31DQ04 MUR410 1N5825 HER302 HER602 SR304 MBR350 50V 31DQ05 50WQ05 SR305 MBR360 50WR06 60V DQ06 50SQ060 SR306 Table4.InductorSelectionbyManufacturer'sPartNumber INDUCTORCODE INDUCTORVALUE SCHOTT(1) PULSEENG.(2) RENCO(3) L47 47μH 67126980 PE-53112 RL2442 L68 68μH 67126990 PE-92114 RL2443 L100 100μH 67127000 PE-92108 RL2444 L150 150μH 67127010 PE-53113 RL1954 L220 220μH 67127020 PE-52626 RL1953 L330 330μH 67127030 PE-52627 RL1952 L470 470μH 67127040 PE-53114 RL1951 L680 680μH 67127050 PE-52629 RL1950 H150 150μH 67127060 PE-53115 RL2445 H220 220μH 67127070 PE-53116 RL2446 H330 330μH 67127080 PE-53117 RL2447 H470 470μH 67127090 PE-53118 RL1961 H680 680μH 67127100 PE-53119 RL1960 H1000 1000μH 67127110 PE-53120 RL1959 H1500 1500μH 67127120 PE-53121 RL1958 H2200 2200μH 67127130 PE-53122 RL2448 (1) SchottCorporation,(612)475-1173,1000ParkersLakeRoad,Wayzata,MN55391. (2) PulseEngineering,(619)674-8100,P.O.Box12235,SanDiego,CA92112. (3) RencoElectronicsIncorporated,(516)586-5566,60JeffrynBlvd.East,DeerPark,NY11729. 9 Power Supply Recommendations As in any switching regulator, layout is very important. Rapidly switching currents associated with wiring inductancegeneratevoltagetransientswhichcancauseproblems.Forminimalinductanceandgroundloops,the length of the leads indicated by heavy lines should be kept as short as possible. Single-point grounding (as indicated) or ground plane construction should be used for best results. When using the adjustable version, physicallylocatetheprogrammingresistorsneartheregulator,tokeepthesensitivefeedbackwiringshort. 24 SubmitDocumentationFeedback Copyright©1999–2016,TexasInstrumentsIncorporated ProductFolderLinks:LM2576 LM2576HV

LM2576,LM2576HV www.ti.com SNVS107D–JUNE1999–REVISEDMAY2016 10 Layout 10.1 Layout Guidelines Board layout is critical for the proper operation of switching power supplies. First, the ground plane area must be sufficient for thermal dissipation purposes. Second, appropriate guidelines must be followed to reduce the effects of switching noise. Switch mode converters are very fast switching devices. In such cases, the rapid increase of input current combined with the parasitic trace inductance generates unwanted L di/dt noise spikes. The magnitude of this noise tends to increase as the output current increases. This noise may turn into electromagnetic interference (EMI) and can also cause problems in device performance. Therefore, take care in layout to minimize the effect of this switching noise. The most important layout rule is to keep the AC current loops as small as possible. Figure 33 shows the current flow in a buck converter. The top schematic shows a dotted line which represents the current flow during the top-switch ON-state. The middle schematic shows the current flow during the top-switch OFF-state. The bottom schematic shows the currents referred to as AC currents. These AC currents are the most critical because they are changing in a very short time period. The dotted lines of the bottom schematic are the traces to keep as short and wide as possible. This also yields a small loop area reducing the loop inductance. To avoid functional problems due to layout, review the PCB layout example. Best results are achieved if the placement of the LM2576 device, the bypass capacitor, the Schottky diode, RFBB, RFBT, and the inductor are placed as shown in Figure 34.TI also recommends using 2-oz copper boards or heavier to help thermal dissipation and to reduce the parasitic inductances of board traces. See applicationnoteAN-1229SIMPLESWITCHER® PCBLayoutGuidelines (SNVA054)formoreinformation. Figure33. CurrentFlowinBuckApplication Copyright©1999–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 25 ProductFolderLinks:LM2576 LM2576HV

LM2576,LM2576HV SNVS107D–JUNE1999–REVISEDMAY2016 www.ti.com 10.2 Layout Example Figure34. LM2576xxLayoutExample 10.3 Grounding To maintain output voltage stability, the power ground connections must be low-impedance (see Figure 26 and Figure 32). For the 5-lead TO-220 and DDPAK/TO-263 style package, both the tab and pin 3 are ground and eitherconnectionmaybeused,astheyarebothpartofthesamecopperleadframe. 10.4 Heat Sink and Thermal Considerations In many cases, only a small heat sink is required to keep the LM2576 junction temperature within the allowed operating range. For each application, to determine whether or not a heat sink is required, the following must be identified: 1. Maximumambienttemperature(intheapplication). 2. Maximumregulatorpowerdissipation(inapplication). 3. Maximum allowed junction temperature (125°C for the LM2576). For a safe, conservative design, a temperatureapproximately15°Ccoolerthanthemaximumtemperaturesmustbeselected. 4. LM2576packagethermalresistancesθ and θ . JA JC TotalpowerdissipatedbytheLM2576canbeestimatedinEquation10: P =(V )(I )+(V /V )(I )(V ) D IN Q O IN LOAD SAT where • I (quiescentcurrent)andV canbefoundinTypicalCharacteristicsshownpreviously, Q SAT • V istheappliedminimuminputvoltage,V istheregulatedoutputvoltage, IN O • andI istheloadcurrent. (10) LOAD 26 SubmitDocumentationFeedback Copyright©1999–2016,TexasInstrumentsIncorporated ProductFolderLinks:LM2576 LM2576HV

LM2576,LM2576HV www.ti.com SNVS107D–JUNE1999–REVISEDMAY2016 Heat Sink and Thermal Considerations (continued) ThedynamiclossesduringturnonandturnoffarenegligibleifaSchottkytypecatchdiodeisused. Whennoheatsinkisused,thejunctiontemperaturerisecanbedeterminedbyEquation11: ΔT =(P )(θ ) (11) J D JA Toarriveattheactualoperatingjunctiontemperature,addthejunctiontemperaturerisetothemaximumambient temperature. T =ΔT +T (12) J J A If the actual operating junction temperature is greater than the selected safe operating junction temperature determinedinstep3,thenaheatsinkisrequired. Whenusingaheatsink,thejunctiontemperaturerisecanbedeterminedbyEquation13: ΔT =(P )(θ +θ +θ ) (13) J D JC interface Heatsink Theoperatingjunctiontemperatureis: T =T +ΔT (14) J A J As in Equation 14, if the actual operating junction temperature is greater than the selected safe operating junctiontemperature,thenalargerheatsinkisrequired(onethathasalowerthermalresistance). Copyright©1999–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 27 ProductFolderLinks:LM2576 LM2576HV

LM2576,LM2576HV SNVS107D–JUNE1999–REVISEDMAY2016 www.ti.com 11 Device and Documentation Support 11.1 Custom Design with WEBENCH Tools CreateaCustomDesignwithWEBENCHTools 11.2 Receiving Notification of Documentation Updates To receive notification of documentation updates, navigate to the device product folder on ti.com. In the upper right corner, click on Alert me to register and receive a weekly digest of any product information that has changed.Forchangedetails,reviewtherevisionhistoryincludedinanyreviseddocument. 11.3 Device Support 11.3.1 DeviceNomenclature 11.3.1.1 DefinitionofTerms BUCKREGULATOR Aswitchingregulatortopologyinwhichahighervoltageisconvertedtoalowervoltage. Alsoknownasastep-downswitchingregulator. BUCK-BOOSTREGULATOR Aswitchingregulatortopologyinwhichapositivevoltageisconvertedtoa negativevoltagewithoutatransformer. DUTYCYCLE(D) Ratiooftheoutputswitch'son-timetotheoscillatorperiod. (15) CATCHDIODEORCURRENTSTEERINGDIODE Thediodewhichprovidesareturnpathfortheloadcurrent whentheLM2576switchisOFF. EFFICIENCY(η) Theproportionofinputpoweractuallydeliveredtotheload. (16) CAPACITOREQUIVALENTSERIESRESISTANCE(ESR) Thepurelyresistivecomponentofarealcapacitor's impedance(seeFigure35).Itcausespowerlossresultingincapacitorheating,whichdirectly affectsthecapacitor'soperatinglifetime.Whenusedasaswitchingregulatoroutputfilter,higher ESRvaluesresultinhigheroutputripplevoltages. Figure35. SimpleModelofaRealCapacitor Moststandardaluminumelectrolyticcapacitorsinthe100μF–1000μFrangehave0.5Ω to 0.1ΩESR.Higher-gradecapacitors(low-ESR,high-frequency,orlow-inductance)inthe100 μFto1000 μFrangegenerallyhaveESRoflessthan0.15Ω. EQUIVALENTSERIESINDUCTANCE(ESL) Thepureinductancecomponentofacapacitor(seeFigure35). Theamountofinductanceisdeterminedtoalargeextentonthecapacitor'sconstruction.Inabuck regulator,thisunwantedinductancecausesvoltagespikestoappearontheoutput. OUTPUTRIPPLEVOLTAGE TheACcomponentoftheswitchingregulator'soutputvoltage.Itisusually dominatedbytheoutputcapacitor'sESRmultipliedbytheinductor'sripplecurrent(ΔI ).The IND peak-to-peakvalueofthissawtoothripplecurrentcanbedeterminedbyreadingInductorRipple Current. CAPACITORRIPPLECURRENT RMSvalueofthemaximumallowablealternatingcurrentatwhichacapacitor canbeoperatedcontinuouslyataspecifiedtemperature. STANDBYQUIESCENTCURRENT(I ) SupplycurrentrequiredbytheLM2576wheninthestandbymode STBY 28 SubmitDocumentationFeedback Copyright©1999–2016,TexasInstrumentsIncorporated ProductFolderLinks:LM2576 LM2576HV

LM2576,LM2576HV www.ti.com SNVS107D–JUNE1999–REVISEDMAY2016 Device Support (continued) (ON /OFFpinisdriventoTTL-highvoltage,thusturningtheoutputswitchOFF). INDUCTORRIPPLECURRENT(ΔI ) Thepeak-to-peakvalueoftheinductorcurrentwaveform,typicallya IND sawtoothwaveformwhentheregulatorisoperatinginthecontinuousmode(vs.discontinuous mode). CONTINUOUS/DISCONTINUOUSMODEOPERATION Relatestotheinductorcurrent.Inthecontinuousmode, theinductorcurrentisalwaysflowingandneverdropstozero,vs.thediscontinuousmode,where theinductorcurrentdropstozeroforaperiodoftimeinthenormalswitchingcycle. INDUCTORSATURATION Theconditionwhichexistswhenaninductorcannotholdanymoremagneticflux. Whenaninductorsaturates,theinductorappearslessinductiveandtheresistivecomponent dominates.InductorcurrentisthenlimitedonlybytheDCresistanceofthewireandtheavailable sourcecurrent. OPERATINGVOLTMICROSECONDCONSTANT(E•T ) Theproduct(inVoIt•μs)ofthevoltageappliedtothe op inductorandthetimethevoltageisapplied.ThisE•T constantisameasureoftheenergy op handlingcapabilityofaninductorandisdependentuponthetypeofcore,thecorearea,the numberofturns,andthedutycycle. 11.4 Documentation Support 11.4.1 RelatedDocumentation Forrelateddocumentation,seethefollowing: AN-1229SIMPLESWITCHER® PCBLayoutGuidelines (SNVA054) 11.5 Related Links The table below lists quick access links. Categories include technical documents, support and community resources,toolsandsoftware,andquickaccesstosampleorbuy. Table5.RelatedLinks TECHNICAL TOOLS& SUPPORT& PARTS PRODUCTFOLDER SAMPLE&BUY DOCUMENTS SOFTWARE COMMUNITY LM2576 Clickhere Clickhere Clickhere Clickhere Clickhere LM2576HV Clickhere Clickhere Clickhere Clickhere Clickhere 11.6 Community Resources The following links connect to TI community resources. Linked contents are provided "AS IS" by the respective contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of Use. TIE2E™OnlineCommunity TI'sEngineer-to-Engineer(E2E)Community.Createdtofostercollaboration amongengineers.Ate2e.ti.com,youcanaskquestions,shareknowledge,exploreideasandhelp solveproblemswithfellowengineers. DesignSupport TI'sDesignSupport QuicklyfindhelpfulE2Eforumsalongwithdesignsupporttoolsand contactinformationfortechnicalsupport. 11.7 Trademarks E2EisatrademarkofTexasInstruments. SIMPLESWITCHER,WEBENCHareregisteredtrademarksofTexasInstruments. Allothertrademarksarethepropertyoftheirrespectiveowners. 11.8 Electrostatic Discharge Caution Thesedeviceshavelimitedbuilt-inESDprotection.Theleadsshouldbeshortedtogetherorthedeviceplacedinconductivefoam duringstorageorhandlingtopreventelectrostaticdamagetotheMOSgates. Copyright©1999–2016,TexasInstrumentsIncorporated SubmitDocumentationFeedback 29 ProductFolderLinks:LM2576 LM2576HV

LM2576,LM2576HV SNVS107D–JUNE1999–REVISEDMAY2016 www.ti.com 11.9 Glossary SLYZ022—TIGlossary. Thisglossarylistsandexplainsterms,acronyms,anddefinitions. 12 Mechanical, Packaging, and Orderable Information The following pages include mechanical, packaging, and orderable information. This information is the most current data available for the designated devices. This data is subject to change without notice and revision of thisdocument.Forbrowser-basedversionsofthisdatasheet,refertotheleft-handnavigation. 30 SubmitDocumentationFeedback Copyright©1999–2016,TexasInstrumentsIncorporated ProductFolderLinks:LM2576 LM2576HV

PACKAGE OPTION ADDENDUM www.ti.com 6-Feb-2020 PACKAGING INFORMATION Orderable Device Status Package Type Package Pins Package Eco Plan Lead/Ball Finish MSL Peak Temp Op Temp (°C) Device Marking Samples (1) Drawing Qty (2) (6) (3) (4/5) LM2576HVS-12 NRND DDPAK/ KTT 5 45 TBD Call TI Call TI -40 to 125 LM2576 TO-263 HVS-12 P+ LM2576HVS-12/NOPB ACTIVE DDPAK/ KTT 5 45 Pb-Free (RoHS SN Level-3-245C-168 HR -40 to 125 LM2576 TO-263 Exempt) HVS-12 P+ LM2576HVS-3.3/NOPB ACTIVE DDPAK/ KTT 5 45 Pb-Free (RoHS SN Level-3-245C-168 HR -40 to 125 LM2576 TO-263 Exempt) HVS-3.3 P+ LM2576HVS-5.0 NRND DDPAK/ KTT 5 45 TBD Call TI Call TI -40 to 125 LM2576 TO-263 HVS-5.0 P+ LM2576HVS-5.0/NOPB ACTIVE DDPAK/ KTT 5 45 Pb-Free (RoHS SN Level-3-245C-168 HR -40 to 125 LM2576 TO-263 Exempt) HVS-5.0 P+ LM2576HVS-ADJ NRND DDPAK/ KTT 5 45 TBD Call TI Call TI -40 to 125 LM2576 TO-263 HVS-ADJ P+ LM2576HVS-ADJ/NOPB ACTIVE DDPAK/ KTT 5 45 Pb-Free (RoHS SN Level-3-245C-168 HR -40 to 125 LM2576 TO-263 Exempt) HVS-ADJ P+ LM2576HVSX-12 NRND DDPAK/ KTT 5 500 TBD Call TI Call TI -40 to 125 LM2576 TO-263 HVS-12 P+ LM2576HVSX-12/NOPB ACTIVE DDPAK/ KTT 5 500 Pb-Free (RoHS SN Level-3-245C-168 HR -40 to 125 LM2576 TO-263 Exempt) HVS-12 P+ LM2576HVSX-3.3/NOPB ACTIVE DDPAK/ KTT 5 500 Pb-Free (RoHS SN Level-3-245C-168 HR -40 to 125 LM2576 TO-263 Exempt) HVS-3.3 P+ LM2576HVSX-5.0 NRND DDPAK/ KTT 5 500 TBD Call TI Call TI -40 to 125 LM2576 TO-263 HVS-5.0 P+ LM2576HVSX-5.0/NOPB ACTIVE DDPAK/ KTT 5 500 Pb-Free (RoHS SN Level-3-245C-168 HR -40 to 125 LM2576 TO-263 Exempt) HVS-5.0 P+ LM2576HVSX-ADJ NRND DDPAK/ KTT 5 500 TBD Call TI Call TI -40 to 125 LM2576 TO-263 HVS-ADJ P+ LM2576HVSX-ADJ/NOPB ACTIVE DDPAK/ KTT 5 500 Pb-Free (RoHS SN Level-3-245C-168 HR -40 to 125 LM2576 TO-263 Exempt) HVS-ADJ P+ LM2576HVT-12 NRND TO-220 KC 5 45 TBD Call TI Call TI -40 to 125 LM2576HVT -12 P+ LM2576HVT-12/LF03 ACTIVE TO-220 NDH 5 45 Green (RoHS SN Level-1-NA-UNLIM LM2576HVT & no Sb/Br) -12 P+ LM2576HVT-12/NOPB ACTIVE TO-220 KC 5 45 Green (RoHS SN Level-1-NA-UNLIM -40 to 125 LM2576HVT & no Sb/Br) -12 P+ Addendum-Page 1

PACKAGE OPTION ADDENDUM www.ti.com 6-Feb-2020 Orderable Device Status Package Type Package Pins Package Eco Plan Lead/Ball Finish MSL Peak Temp Op Temp (°C) Device Marking Samples (1) Drawing Qty (2) (6) (3) (4/5) LM2576HVT-15/LB03 NRND TO-220 NDH 5 45 TBD Call TI Call TI LM2576HVT -15 P+ LM2576HVT-15/LF03 ACTIVE TO-220 NDH 5 45 Green (RoHS SN Level-1-NA-UNLIM LM2576HVT & no Sb/Br) -15 P+ LM2576HVT-15/NOPB ACTIVE TO-220 KC 5 45 Green (RoHS SN Level-1-NA-UNLIM -40 to 125 LM2576HVT & no Sb/Br) -15 P+ LM2576HVT-5.0 NRND TO-220 KC 5 45 TBD Call TI Call TI -40 to 125 LM2576HVT -5.0 P+ LM2576HVT-5.0/LB03 NRND TO-220 NDH 5 45 TBD Call TI Call TI LM2576HVT -5.0 P+ LM2576HVT-5.0/LF02 ACTIVE TO-220 NEB 5 45 Green (RoHS SN Level-1-NA-UNLIM LM2576HVT & no Sb/Br) -5.0 P+ LM2576HVT-5.0/LF03 ACTIVE TO-220 NDH 5 45 Green (RoHS SN Level-1-NA-UNLIM LM2576HVT & no Sb/Br) -5.0 P+ LM2576HVT-5.0/NOPB ACTIVE TO-220 KC 5 45 Green (RoHS SN Level-1-NA-UNLIM -40 to 125 LM2576HVT & no Sb/Br) -5.0 P+ LM2576HVT-ADJ NRND TO-220 KC 5 45 TBD Call TI Call TI -40 to 125 LM2576HVT -ADJ P+ LM2576HVT-ADJ/LB03 NRND TO-220 NDH 5 45 TBD Call TI Call TI LM2576HVT -ADJ P+ LM2576HVT-ADJ/LF03 ACTIVE TO-220 NDH 5 45 Green (RoHS SN Level-1-NA-UNLIM LM2576HVT & no Sb/Br) -ADJ P+ LM2576HVT-ADJ/NOPB ACTIVE TO-220 KC 5 45 Green (RoHS SN Level-1-NA-UNLIM -40 to 125 LM2576HVT & no Sb/Br) -ADJ P+ LM2576S-12 NRND DDPAK/ KTT 5 45 TBD Call TI Call TI -40 to 125 LM2576S TO-263 -12 P+ LM2576S-12/NOPB ACTIVE DDPAK/ KTT 5 45 Pb-Free (RoHS SN Level-3-245C-168 HR -40 to 125 LM2576S TO-263 Exempt) -12 P+ LM2576S-3.3/NOPB ACTIVE DDPAK/ KTT 5 45 Pb-Free (RoHS SN Level-3-245C-168 HR -40 to 125 LM2576S TO-263 Exempt) -3.3 P+ LM2576S-5.0 NRND DDPAK/ KTT 5 45 TBD Call TI Call TI -40 to 125 LM2576S TO-263 -5.0 P+ LM2576S-5.0/NOPB ACTIVE DDPAK/ KTT 5 45 Pb-Free (RoHS SN Level-3-245C-168 HR -40 to 125 LM2576S TO-263 Exempt) -5.0 P+ LM2576S-ADJ/NOPB ACTIVE DDPAK/ KTT 5 45 Pb-Free (RoHS SN Level-3-245C-168 HR -40 to 125 LM2576S TO-263 Exempt) -ADJ P+ Addendum-Page 2

PACKAGE OPTION ADDENDUM www.ti.com 6-Feb-2020 Orderable Device Status Package Type Package Pins Package Eco Plan Lead/Ball Finish MSL Peak Temp Op Temp (°C) Device Marking Samples (1) Drawing Qty (2) (6) (3) (4/5) LM2576SX-3.3/NOPB ACTIVE DDPAK/ KTT 5 500 Pb-Free (RoHS SN Level-3-245C-168 HR -40 to 125 LM2576S TO-263 Exempt) -3.3 P+ LM2576SX-5.0/NOPB ACTIVE DDPAK/ KTT 5 500 Pb-Free (RoHS SN Level-3-245C-168 HR -40 to 125 LM2576S TO-263 Exempt) -5.0 P+ LM2576SX-ADJ/NOPB ACTIVE DDPAK/ KTT 5 500 Pb-Free (RoHS SN Level-3-245C-168 HR -40 to 125 LM2576S TO-263 Exempt) -ADJ P+ LM2576T-12 NRND TO-220 KC 5 45 TBD Call TI Call TI -40 to 125 LM2576T -12 P+ LM2576T-12/LB03 NRND TO-220 NDH 5 45 TBD Call TI Call TI LM2576T -12 P+ LM2576T-12/LF03 ACTIVE TO-220 NDH 5 45 Green (RoHS SN Level-1-NA-UNLIM LM2576T & no Sb/Br) -12 P+ LM2576T-12/NOPB ACTIVE TO-220 KC 5 45 Green (RoHS SN Level-1-NA-UNLIM -40 to 125 LM2576T & no Sb/Br) -12 P+ LM2576T-15/LF03 ACTIVE TO-220 NDH 5 45 Green (RoHS SN Level-1-NA-UNLIM LM2576T & no Sb/Br) -15 P+ LM2576T-15/NOPB ACTIVE TO-220 KC 5 45 Green (RoHS SN Level-1-NA-UNLIM -40 to 125 LM2576T & no Sb/Br) -15 P+ LM2576T-3.3/LF03 ACTIVE TO-220 NDH 5 45 Green (RoHS SN Level-1-NA-UNLIM LM2576T & no Sb/Br) -3.3 P+ LM2576T-3.3/NOPB ACTIVE TO-220 KC 5 45 Green (RoHS SN Level-1-NA-UNLIM -40 to 125 LM2576T & no Sb/Br) -3.3 P+ LM2576T-5.0 NRND TO-220 KC 5 45 TBD Call TI Call TI -40 to 125 LM2576T -5.0 P+ LM2576T-5.0/LB03 NRND TO-220 NDH 5 45 TBD Call TI Call TI LM2576T -5.0 P+ LM2576T-5.0/LF02 ACTIVE TO-220 NEB 5 45 Green (RoHS SN Level-1-NA-UNLIM LM2576T & no Sb/Br) -5.0 P+ LM2576T-5.0/LF03 ACTIVE TO-220 NDH 5 45 Green (RoHS SN Level-1-NA-UNLIM LM2576T & no Sb/Br) -5.0 P+ LM2576T-5.0/NOPB ACTIVE TO-220 KC 5 45 Green (RoHS SN Level-1-NA-UNLIM -40 to 125 LM2576T & no Sb/Br) -5.0 P+ LM2576T-ADJ NRND TO-220 KC 5 45 TBD Call TI Call TI -40 to 125 LM2576T -ADJ P+ LM2576T-ADJ/LB03 NRND TO-220 NDH 5 45 TBD Call TI Call TI LM2576T -ADJ P+ Addendum-Page 3

PACKAGE OPTION ADDENDUM www.ti.com 6-Feb-2020 Orderable Device Status Package Type Package Pins Package Eco Plan Lead/Ball Finish MSL Peak Temp Op Temp (°C) Device Marking Samples (1) Drawing Qty (2) (6) (3) (4/5) LM2576T-ADJ/LF02 ACTIVE TO-220 NEB 5 45 Green (RoHS SN Level-1-NA-UNLIM LM2576T & no Sb/Br) -ADJ P+ LM2576T-ADJ/LF03 ACTIVE TO-220 NDH 5 45 Green (RoHS SN Level-1-NA-UNLIM LM2576T & no Sb/Br) -ADJ P+ LM2576T-ADJ/NOPB ACTIVE TO-220 KC 5 45 Green (RoHS SN Level-1-NA-UNLIM -40 to 125 LM2576T & no Sb/Br) -ADJ P+ (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of <=1000ppm threshold. Antimony trioxide based flame retardants must also meet the <=1000ppm threshold requirement. (3) MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. (4) There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device. (5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation of the previous line and the two combined represent the entire Device Marking for that device. (6) Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish values may wrap to two lines if the finish value exceeds the maximum column width. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis. Addendum-Page 4

PACKAGE OPTION ADDENDUM www.ti.com 6-Feb-2020 Addendum-Page 5

PACKAGE MATERIALS INFORMATION www.ti.com 29-Sep-2019 TAPE AND REEL INFORMATION *Alldimensionsarenominal Device Package Package Pins SPQ Reel Reel A0 B0 K0 P1 W Pin1 Type Drawing Diameter Width (mm) (mm) (mm) (mm) (mm) Quadrant (mm) W1(mm) LM2576HVSX-12 DDPAK/ KTT 5 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2 TO-263 LM2576HVSX-12/NOPB DDPAK/ KTT 5 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2 TO-263 LM2576HVSX-3.3/NOPB DDPAK/ KTT 5 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2 TO-263 LM2576HVSX-5.0 DDPAK/ KTT 5 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2 TO-263 LM2576HVSX-5.0/NOPB DDPAK/ KTT 5 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2 TO-263 LM2576HVSX-ADJ DDPAK/ KTT 5 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2 TO-263 LM2576HVSX-ADJ/NOPB DDPAK/ KTT 5 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2 TO-263 LM2576SX-3.3/NOPB DDPAK/ KTT 5 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2 TO-263 LM2576SX-5.0/NOPB DDPAK/ KTT 5 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2 TO-263 LM2576SX-ADJ/NOPB DDPAK/ KTT 5 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2 TO-263 PackMaterials-Page1

PACKAGE MATERIALS INFORMATION www.ti.com 29-Sep-2019 *Alldimensionsarenominal Device PackageType PackageDrawing Pins SPQ Length(mm) Width(mm) Height(mm) LM2576HVSX-12 DDPAK/TO-263 KTT 5 500 367.0 367.0 45.0 LM2576HVSX-12/NOPB DDPAK/TO-263 KTT 5 500 367.0 367.0 45.0 LM2576HVSX-3.3/NOPB DDPAK/TO-263 KTT 5 500 367.0 367.0 45.0 LM2576HVSX-5.0 DDPAK/TO-263 KTT 5 500 367.0 367.0 45.0 LM2576HVSX-5.0/NOPB DDPAK/TO-263 KTT 5 500 367.0 367.0 45.0 LM2576HVSX-ADJ DDPAK/TO-263 KTT 5 500 367.0 367.0 45.0 LM2576HVSX-ADJ/NOPB DDPAK/TO-263 KTT 5 500 367.0 367.0 45.0 LM2576SX-3.3/NOPB DDPAK/TO-263 KTT 5 500 367.0 367.0 45.0 LM2576SX-5.0/NOPB DDPAK/TO-263 KTT 5 500 367.0 367.0 45.0 LM2576SX-ADJ/NOPB DDPAK/TO-263 KTT 5 500 367.0 367.0 45.0 PackMaterials-Page2

MECHANICAL DATA NDH0005D www.ti.com

MECHANICAL DATA KTT0005B TS5B (Rev D) BOTTOM SIDE OF PACKAGE www.ti.com

MECHANICAL DATA NEB0005B www.ti.com

PACKAGE OUTLINE KC0005A TO-220 - 16.51 mm max height SCALE 0.850 TO-220 4.83 B 4.06 10.67 1.40 AAAAA 8.89 3.05 9.65 1.14 6.86 2.54 6.86 (6.275) 5.69 3.71-3.96 OPTIONAL 12.88 CHAMFER 10.08 16.51 2X (R1) MAX OPTIONAL 9.25 7.67 (4.25) C PIN 1 ID (OPTIONAL) NOTE 3 14.73 12.29 1 5 0.61 1.02 5X 0.30 0.64 3.05 0.25 C A B 2.03 4X 1.7 6.8 1 5 4215009/A 01/2017 NOTES: 1. All controlling linear dimensions are in inches. Dimensions in brackets are in millimeters. Any dimension in brackets or parenthesis are for reference only. Dimensioning and tolerancing per ASME Y14.5M. 2. This drawing is subject to change without notice. 3. Shape may vary per different assembly sites. www.ti.com

EXAMPLE BOARD LAYOUT KC0005A TO-220 - 16.51 mm max height TO-220 4X (1.45) PKG 0.07 MAX METAL 0.07 MAX ALL AROUND (1.45) TYP ALL AROUND PKG (2) 4X (2) 1 5 (R0.05) TYP SOLDER MASK FULL R (1.7) TYP OPENING, TYP TYP 5X ( 1.2) (6.8) LAND PATTERN NON-SOLDER MASK DEFINED SCALE:12X 4215009/A 01/2017 www.ti.com

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