LM2675 SIMPLE SWITCHER® Power Converter High Efficiency …

1 Copyright 2016, Texas Instruments IncorporatedProductFolderSample &BuyTechnicalDocumentsTools &SoftwareSupport &CommunityAn IMPORTANTNOTICEat the end of this datasheetaddressesavailability,warranty, changes,use in safety-criticalapplications,intellectual propertymattersand MAY2004 REVISEDJUNE2016LM2675 SIMPLESWITCHER PowerConverterHigh Efficiency1-A Step-DownVoltageRegulator11 Features1 Efficiencyup to 96% Availablein 8-PinSOIC,PDIP,and 16-PinWSONP ackage Requiresonly 5 ExternalComponents ,5-V, 12-V,and AdjustableOutputVersions 37 V and LoadConditions Ensured1-A OutputLoadCurrent WideInputVoltageRange:8 V to 40 V 260-kHzFixedFrequencyInternalOscillator TTL ShutdownCapability,Low-PowerStandbyMode ThermalShutdownand CurrentLimitProtection2 Applications SimpleHighEfficiency(>90%)Step-Down(Buck )Regulator EfficientPreregulatorfor LinearRegulators Positive-to-NegativeConverter3 DescriptionTheLM2675seriesof theactivefunctionsfor a step-down(buck)switchingregulator,capabl eof drivinga 1-A loadcurrentwithexcellentline and fixedoutputvoltagesof V, 5 V, 12 V,and an minimumnumberofexternalcomponents,theser egulatorsare simpleto use andincludepatentedinternalfrequencycompe nsationand a LM2675seriesoperatesat a switchingfrequencyof 260kHz,thusallowingsmaller-sizedfilterco mponentsthanwhatwouldbe its veryhighefficiency(>90%),the coppertraceson theprinted-circuitboardare the only (1)PARTNUMBERPACKAGEBODYSIZE(NOM) LM2675 SOIC(8) (8) (16) (1) For all availablepackages,see the orderableaddendumatthe end of the MAY2004.

2 LM2675 SubmitDocumentationFeedbackCopyright 2004 2016,TexasInstrumentsIncorporatedTableof Contents1 Description(continued)..36 Pin Configurationand V .. 5 V .. 12 V .. All Applicationand Deviceand Mechanical,Packaging,and RevisionHistoryNOTE:Pagenumbersfor previousrevisionsmay differfrompagenumbersin the (June2005)to RevisionFPage AddedESDR atingstable,FeatureDescriptionsection,De viceFunctionalModes,Applicationand Implementationsection,PowerSupplyRecomme ndationssection,Layoutsection,Deviceand DocumentationSupportsection,andMechanica l,Packaging,and Deletedall instancesof the computerdesignsoftwareLM267 XMadeSimple( ) ..1 Not to scaleDAP1CB 16 VSW 2NC15 VSW 3NC14 VIN 4NC13 NC5NC12 GND6NC11 GND7NC10 NC8FB9 ON/OFFNot to scale1CB 8 VSW 2NC7 VIN 3NC6 GND4FB5 MAY2004 REVISEDJUNE2016 ProductFolderLinks: LM2675 SubmitDocumentationFeedbackCopyright 2004 2016,TexasInstrumentsIncorporated5 Description(continued)A familyof standardinductorsfor use with the LM2675are designof switch-modepowersuppliesusingtheseadvanc edICs.

3 Alsoincludedinthe datasheetare selectorguidesfor diodesand capacitorsdesignedto workin outputvoltagewithinspecifiedinputvoltage sandoutputloadconditions,and 10%on the included,featuringtypically50- A stand-by outputswitchincludescurrentlimiting,as well as thermalshutdownfor full Pin Configurationand FunctionsD or P Package8-PinSOICor PDIPTop ViewNHNP ackage16-PinWSONTop ViewPin FunctionsPINI/ODESCRIPTIONNAMED, PNHNCB11 IBoot-strapcapacitorconnectionfor high quality470-nFcapacitorfromCBto Connectto the midpointof feedbackdividerto setVOUTfor adjustableversionor connectthis pin directlyto the outputcapacitorfor a , 12 of CINand CINmustbe as shortas , 32, 3, 4, 5,6, 7, 10, 13 No the ON and low = this pinhigh or float to enablethe to collectorpin of high side powersupplyandinputbypasscapacitorsCIN. PathfromVIN pin to high frequencybypassCINand GNDmustbe as shortas , 16 OSourcepin of the is a to an inductorand the cathodeof the MAY2004 : LM2675 SubmitDocumentationFeedbackCopyright 2004 2016,TexasInstrumentsIncorporated(1)Stre ssesbeyondthoselistedunderAbsoluteMaximu mRatingsmay causepermanentdamageto the stressratingsonly,whichdo not implyfunctionaloperationof the deviceat theseor any otherconditionsbeyondthoseindicatedunder RecommendedOperatingConditions.

4 Exposureto absolute-maximum-ratedconditionsfor extendedperiodsmay affectdevicereliability.(2)If Military/Aerospacespecifieddevicesare required,contactthe TexasInstrumentsSalesOffice/Distributors for 40 C to 125 C (unlessotherwisenoted)(1)(2)MINMAXUNITS upplyvoltage45 VON/OFFpin voltage,VSH ground 1 VBoostpin voltageVSW+ 8 VFeedbackpin voltage,VFB packageVaporphase(60 s)215 CInfrared(15 s)220P package(soldering,10 s)260 NHNpackageSeeAN-1187 Maximumjunctiontemperature,TJ150 CStoragetemperature,Tstg 65150 C(1)JEDEC documentJEP155statesthat 500-VHBM allowssafe manufacturingwith a standardESDcontrolprocess.(2)The human-bodymodelis a 100-pFcapacitordischargedthrougha resistorinto (ESD)ElectrostaticdischargeHuman-bodymod el(HBM),per ANSI/ESDA/JEDECJS-001(1)(2) (unlessotherwisenoted) 40125 C(1)For moreinformationabouttraditionaland new thermalmetrics,see theSemiconductorand IC PackageThermalMetricsapplicationreport.( 2)Thermalresistancesweresimulatedon 4-layerJEDEC board.

5 (3)Junction-to-ambientthermalresistancew ith approximately1 squareinch of printed-circuitboardcoppersurroundingthe the applicationnoteaccompanyingthis valueR JAfor the WSON(NHN)packageis specificallydependenton PCBtracearea,tracematerial,and the numberoflayersand improvedthermalresistanceand powerdissipationfor the WSON package,refertoAN-1187 LeadlessLeadframePackage(LLP). (1)(2) LM2675 UNITSOIC(D)PDIP(P)NHN(WSON)8 PINS8 PINS16 PINSR JAJunction-to-ambientthermalresistance(3 )10595 C/WR JC(top)Junction-to-case(top)thermalresis tance C/WR JBJunction-to-boardthermalresistance C/W JTJunction-to-topcharacterizationparamet er C/W JBJunction-to-boardcharacterizationparam eter C/WR JC(bot)Junction-to-case(bottom)thermalre sistance MAY2004 REVISEDJUNE2016 ProductFolderLinks: LM2675 SubmitDocumentationFeedbackCopyright 2004 2016,TexasInstrumentsIncorporated(1)Exte rnalcomponentssuchas the catchdiode,inductor,inputand outputcapacitors,and voltageprogrammingresistorscan LM2675is usedas shownin Figure19 test circuits,systemperformanceis as specifiedbythe systemparameterssectionofElectricalChara cteristics.

6 (2)All limitsspecifiedat roomtemperatureand at roomtemperaturelimitsare 100% limitsat temperatureextremesare specifiedthroughcorrelationusingstandard StatisticalQualityControl(SQC) limitsare usedto calculateAverageOutgoingQualityLevel(AOQ L).(3)Typicalnumbersare at 25 C and representthe VTJ= 25 C (unlessotherwisenoted;see Figure19)(1)PARAMETERTESTCONDITIONSMIN(2 )TYP(3)MAX(2)UNITVOUTO utputvoltageVIN= 8 V to 40 V, ILOAD= 20 mA to 1 ATJ= 25 40 C to 125 V to 40 V,ILOAD= 20 mA to 500 mATJ= 25 40 C to 125 EfficiencyVIN= 12 V, ILOAD= 1 A86%(1)Externalcomponentssuchas the catchdiode,inductor,inputand outputcapacitors,and voltageprogrammingresistorscan LM2675is usedas shownin Figure19 test circuits,systemperformanceis as specifiedbythe systemparameterssectionofElectricalChara cteristics.(2)All limitsspecifiedat roomtemperatureand at roomtemperaturelimitsare 100% limitsat temperatureextremesare specifiedthroughcorrelationusingstandard StatisticalQualityControl(SQC) limitsare usedto calculateAverageOutgoingQualityLevel(AOQ L).

7 (3)Typicalnumbersare at 25 C and representthe 5 VTJ= 25 C (unlessotherwisenoted;see Figure19)(1)PARAMETERTESTCONDITIONSMIN(2 )TYP(3)MAX(2)UNITVOUTO utputvoltageVIN= 8 V to 40 V, ILOAD= 20 mA to 1 ATJ= 25 40 C to 125 V to 40 V,ILOAD= 20 mA to 500 mATJ= 25 40 C to 125 EfficiencyVIN= 12 V, ILOAD= 1 A90%(1)Externalcomponentssuchas the catchdiode,inductor,inputand outputcapacitors,and voltageprogrammingresistorscan LM2675is usedas shownin Figure19 test circuits,systemperformanceis as specifiedbythe systemparameterssectionofElectricalChara cteristics.(2)All limitsspecifiedat roomtemperatureand at roomtemperaturelimitsare 100% limitsat temperatureextremesare specifiedthroughcorrelationusingstandard StatisticalQualityControl(SQC) limitsare usedto calculateAverageOutgoingQualityLevel(AOQ L).(3)Typicalnumbersare at 25 C and representthe 12 VTJ= 25 C (unlessotherwisenoted;see Figure19)(1)PARAMETERTESTCONDITIONSMIN(2 )TYP(3)MAX(2)UNITVOUTO utputvoltageVIN= 15 V to 40 V, ILOAD= 20 mA to 1 ATJ= 25 40 C to 125 EfficiencyVIN= 24 V, ILOAD= 1 A94%6LM2675 SNVS129F MAY2004 : LM2675 SubmitDocumentationFeedbackCopyright 2004 2016,TexasInstrumentsIncorporated(1)Exte rnalcomponentssuchas the catchdiode,inductor,inputand outputcapacitors,and voltageprogrammingresistorscan LM2675is usedas shownin Figure19 test circuits,systemperformanceis as specifiedbythe systemparameterssectionofElectricalChara cteristics.

8 (2)All limitsspecifiedat roomtemperatureand at roomtemperaturelimitsare 100% limitsat temperatureextremesare specifiedthroughcorrelationusingstandard StatisticalQualityControl(SQC) limitsare usedto calculateAverageOutgoingQualityLevel(AOQ L).(3)Typicalnumbersare at 25 C and representthe AdjustableTJ= 25 C (unlessotherwisenoted;see Figure19)(1)PARAMETERTESTCONDITIONSMIN(2 )TYP(3)MAX(2)UNITVFBF eedbackvoltageVIN= 8 V to 40 V, ILOAD= 20 mA to 1 A,VOUT programmedfor 5 V (seeFigure19)TJ= 25 40 C to 125 V to 40 V, ILOAD= 20 mA to 500mA, VOUT programmedfor 5 V (seeFigure19)TJ= 25 40 C to 125 EfficiencyVIN= 12 V, ILOAD= 1 A90%(1)All limitsspecifiedat roomtemperatureand at roomtemperaturelimitsare 100% limitsat temperatureextremesare specifiedthroughcorrelationusingstandard StatisticalQualityControl(SQC) limitsare usedto calculateAverageOutgoingQualityLevel(AOQ L).(2)Typicalnumbersare at 25 C and representthe All OutputVoltageVersionsTJ= 25 C, VIN= 12 V for the V, 5 V, and adjustableversions,and VIN= 24 V for the 12 V version,and ILOAD= 100 mA(unlessotherwisenoted)PARAMETERTESTCON DITIONSMIN(1)TYP(2)MAX(1)UNITIQQ uiescentcurrentVFEEDBACK= 8 V for V, 5 V, and 15 V for 12 V = 0 VTJ= 25 C50100 ATJ= 40 C to 125 C150 ICLC urrentlimitTJ= 25 40 C to 125 0 V, ON/OFFPin = 0 V, VIN= 40 V125 AVSWITCH= 1 V, ON/OFFPin = 0 V615mARDS(ON)Switchon-resistanceISWITCH= 1 ATJ= 25 TJ= 40 C to 125 switchpinTJ= 25 C260kHzTJ= 40 C to 125 C225275 DMinimumduty cycleTJ= 25 C95%TJ= 40 C to 125 C0%IBIASF eedbackbias currentVFEEDBACK= V, adjustableversiononly85nAVS/DON/OFFpin voltageTJ= 25 40 C to 125 currentON/OFFPin = 0 VTJ= 25 C20 ATJ= 40 C to 125 MAY2004 REVISEDJUNE2016 ProductFolderLinks: LM2675 SubmitDocumentationFeedbackCopyright 2004 2016, NormalizedOutputVoltageFigure2.

9 LineRegulationFigure3. EfficiencyFigure4. Drain-to-SourceResistanceFigure5. SwitchCurrentLimitFigure6. OperatingQuiescentCurrent8LM2675 SNVS129F MAY2004 : LM2675 SubmitDocumentationFeedbackCopyright 2004 2016,TexasInstrumentsIncorporatedTypical Characteristics(continued)Figure7. StandbyQuiescentCurrentFigure8. ON/OFFT hresholdVoltageFigure9. ON/OFFPin Current(Sourcing)Figure10. SwitchingFrequencyFigure11. FeedbackPin BiasCurrentFigure12. MAY2004 REVISEDJUNE2016 ProductFolderLinks: LM2675 SubmitDocumentationFeedbackCopyright 2004 2016,TexasInstrumentsIncorporatedTypical Characteristics(continued)Figure13. DropoutVoltage, DropoutVoltage,5-V FixedOutputVoltageVersionssee Figure19 VSWpin voltage,10 V/divVIN= 20 V, VOUT= 5 V,Inductorcurrent, A/divILOAD= 1 A, L = 47 H,Outputripplevoltage,20 mV/divAC-coupledCOUT= 68 F,COUTESR= 50 m Figure15. ContinuousModeSwitchingWaveforms,Horizon talTimeBase:1 s/divVSWpin voltage,10 V/divVIN= 20 V, VOUT= 5 V,Inductorcurrent, A/divILOAD= 300 mA, L = 15 H,Outputripplevoltage,20 mV/divAC-coupledCOUT= 68 F (2 ),COUTESR= 25 m Figure16.

10 DiscontinuousModeSwitchingWaveforms,Hori zontalTimeBase:1 s/divOutputvoltage,100 mV/div,VIN= 20 V, VOUT= 5 V,AC-coupledILOAD= 1 A, L = 47 H,Loadcurrent:200-mAto 1-A load pulseCOUT= 68 F,COUTESR= 50 m Figure17. LoadTransientResponsefor ContinuousMode,HorizontalTimeBase:50 s/divOutputvoltage,100 mV/div,VIN= 20 V, VOUT= 5 V,AC-coupledL = 47 H,Loadcurrent:100-mAto 400-mAload pulseCOUT= 68 F (2 ),COUTESR= 50 m Figure18. LoadTransientResponsefor DiscontinuousMode,HorizontalTimeBase:200 s/divCopyright 2016, Texas Instruments Incorporated10LM2675 SNVS129F MAY2004 : LM2675 SubmitDocumentationFeedbackCopyright 2004 2016,TexasInstrumentsIncorporated8 LM2675providesall of the activefunctionsrequiredfor a step-down(buck) internalpowerswitchis a DMOS powerMOSFETto providepowersupplydesignswith high currentcapability,up to 1 A,and LM2675is part of the SIMPLESWITCHER familyof minimumnumberof externalcomponents,whichhavebeenpredeter minedfromavarietyof datasheetor TI's WEBENCH designtool,a completeswitchingpowersupplycan be HighEfficiency3A Step-DownVoltageRegulatorwith Syncfor voltageregulationloop in the LM2675regulatesoutputvoltageby maintainingthe voltageon FB pin (VFB) tobe the sameas the internalREFvoltage(VREF).