12A High Efficiency Synchronous Buck Regulator w ...

1 FBPGOODVINLM21212-2 VOUTAGNDCOMPPVINFADJSWENCINCOUTLOUTRC1CC 1CC2CC3 RFB1 RFB2RC2 PGNDAVINCF111-1634171918208,9,105,6,7 RFSS/TRKCSS2optionalHTSSOP-20optionalRAD JP roductFolderOrderNowTechnicalDocumentsTo ols &SoftwareSupport &CommunityAn IMPORTANTNOTICEat the end of this datasheetaddressesavailability,warranty, changes,use in safety-criticalapplications,intellectual propertymattersand MARCH2011 , 12-A, Voltage-ModeSynchronousBuck RegulatorWith AdjustableFrequency11 Features1 Integrated7-m HighSideand Low-SideFET Switches 300-kHzto V to VIN(100%DutyCycleCapable), 1% Reference to V StartupInto PrebiasedLoads OutputVoltageTrackingCapability WideBandwidthVoltageLoopErrorAmplifier AdjustableSoft-StartWithExternalCapacito r PrecisionEnablePin WithHysteresis IntegratedOVP,OCP,OTP,UVLO,and Power-Good ThermallyEnhanced20-PinHTSSOPE xposedPad Package Createa customdesignusingthe lm21212 -2withthe WEBENCH PowerDesigner2 Applications Broadband,Networkingand WirelessCommunications High-PerformanceFPGAs,ASIC sandMicroprocessors Simpleto Design,HighEfficiencyPointof LoadRegulationfroma 5-V or DescriptionTheLM21212-2is a monolithicsynchronousbuckregulatorthat is capableof deliveringup to 12 A ofcontinuousoutputcurrentwhileproducinga n outputvoltagedownto V deviceis optimizedto workoveran inputvoltagerangeof to V.

2 Makingit suitablefor a widevarietyof low provideshigh noiseimmunityand narrowduty-cyclecapability,and it can be compensatedtobe stablewithanytypeof outputcapacitance,providingmaximumflexib ilityand easeof (OVP)andovercurrentprotection(OCP)for precisionenablepinand integratedUVLO allowturnonof the deviceto limitedby bothan (1)PARTNUMBERPACKAGEBODYSIZE(NOM) lm21212 -2 HTSSOP(20) (1) For all availablepackages,see the orderableaddendumatthe end of the MARCH2011 : lm21212 -2 SubmitDocumentationFeedbackCopyright 2011 2019,TexasInstrumentsIncorporatedTableof Contents1 Description, Pin Configurationand Applicationand Deviceand Mechanical,Packaging,and RevisionHistoryNOTE:Pagenumbersfor previousrevisionsmay differfrompagenumbersin the (March2013)to RevisionBPage Editorialchangesonly,no technicalrevisions;add linksfor (March2013)to RevisionAPage Changedlayoutof NationalSemiconductordatasheetto TI MARCH2011 REVISEDJUNE2019 ProductFolderLinks: lm21212 -2 SubmitDocumentationFeedbackCopyright 2011 2019,TexasInstrumentsIncorporated5 Description,continuedThe lm21212 -2is designedto workwell in outputvoltageof the devicecan be configuredto trackan externalvoltagerail usingthe SS/TRKpin.

3 Theswitchingfrequencycan beprogrammedbetween300 kHz and an the outputis prebiasedat start-up,it doesnot sinkcurrent,allowingthe outputto smoothlyrise regulatoris offeredin a 20-pinHTSSOP packagewithan exposedpad that can besolderedto the PCB,eliminatingthe needfor ViewPGNDPGND1211 SW910SW4LM21212-2 SNVS715B MARCH2011 : lm21212 -2 SubmitDocumentationFeedbackCopyright 2011 2019,TexasInstrumentsIncorporated6 Pin Configurationand FunctionsPWPP ackage20-PinHTSSOPP ackageTop ViewPin The switchingfrequencycan be set to a predeterminedrate by connectinga resistorbetweenFADJand An internal2 A currentsourcechargesan externalcapacitorconnectedbetweenthis pin and AGNDto set the outputvoltageramprate pin can also be usedtoconfigurethe enableinputfor the not used,the EN pin can be left open,whichwill go high due toan generatesthe is recommendedto connectPVINto AVIN througha low passRC filter to minimizethe influenceof inputrail rippleand noiseon the ,6,7 PVINI nputvoltageto the powerswitchesinsidethe shouldbe connectedtogetherat low ESRinputcapacitanceshouldbe locatedas closeas possibleto ,9.

4 10 PGNDP owergroundpins for the shouldbe tied togetherlocallyand connectedto the filter is connectedto the outputof the voltageloop is connectedto the invertinginputof the voltageloop the internalreferenceand bias on the undersideof the packagewith an electricaland thermalconnectionto recommendedto connectthis pad to the PC boardgroundplanein orderto MARCH2011 REVISEDJUNE2019 ProductFolderLinks: lm21212 -2 SubmitDocumentationFeedbackCopyright 2011 2019,TexasInstrumentsIncorporated(1)Abso luteMaximumRatingsindicatelimitsbeyondwi tchdamageto the devicemay whichthe deviceis intendedto be functional,but do not ensuredspecificationsand test conditions,see theElectricalCharacteristics.(2)If Military/Aerospacespecifieddevicesare required,contactthe TexasInstrumentsSalesOffice/Distributors for availabilityandspecifications.(3)The PVINpin can toleratetransientvoltagesup to V for a periodof up to 6ns.

5 Thesetransientscan occurduringthe normaloperationof the device.(4)The SW pin can toleratetransientvoltagesup to 9 V for a periodof up to 6 ns, and -1 V for a durationof 4 ns. Thesetransientscanoccurduringthe normaloperationof the (1)(2)PVIN(3), AVINto GND +6 VSW(4), EN, FB, COMP,PGOOD,SS/TRK,FADJto GND PVIN+ 65 C to 150 CSolderingSpecificationfor TSSOPPb-FreeInfraredor Convection(30 sec)260 C(1)JEDEC documentJEP155statesthat 500-VHBM allowssafe manufacturingwith a (ESD)ElectrostaticdischargeHuman-bodymod el(HBM),per ANSI/ESDA/JEDECJS-001(1) 2000V(1)Thermalmeasurementswereperformed on a 2x2 inch,4 layer,2 oz. copperouterlayer,1 twelve8 underneaththe EP of the deviceand an additionalsixteen8 mil. vias underthe ,AVINto GND+ + 40 C to +125 C JA(1)24 ,the followingconditionsapply:VPVIN,AVIN= 5V. Limitsin standardtype are for TJ= 25 C only,limitsinboldfacetypeapplyoverthe junctiontemperature(TJ) rangeof 40 C to +125 C.

6 Minimumand maximumlimitsarespecifiedthroughtest, design,or mostlikelyparametricnormat TJ= 25 C,and are providedfor voltageVIN= VOUT/ VOUT/ VINLine ResistanceISW= RDSONLSLow SideSwitchOn ResistanceISW= ICLRHS RisingSwitchCurrentLimit151719 AICLFLS 0V5070 accuracy(VSS- VFB)0 < VTRACK< A6LM21212-2 SNVS715B MARCH2011 : lm21212 -2 SubmitDocumentationFeedbackCopyright 2011 2019,TexasInstrumentsIncorporatedElectri calCharacteristics(continued)Unlessother wisestated,the followingconditionsapply:VPVIN,AVIN= 5V. Limitsin standardtype are for TJ= 25 C only,limitsinboldfacetypeapplyoverthe junctiontemperature(TJ) rangeof 40 C to +125 C. Minimumand maximumlimitsarespecifiedthroughtest, design,or mostlikelyparametricnormat TJ= 25 C,and are providedfor VrefCSS= 0350500675 stRESETSSD eviceResetto Soft-StartRamp50110200 sOSCILLATORfRNGFADJF requencyRange3001550kHzfSWSwitchingFrequ encyRADJ= 140015501700kHzRADJ= 465500535tHSBLANKHS OCPB lankingTimeRisingedgeof SW to ICLR comparison55nstLSBLANKLS OCPB lankingTimeFallingedgeof SW to ICLF comparison400nstZXBLANKZeroCrossBlanking TimeFallingedgeof SW to VZXcomparison120nstMINONM inimumHS on-time140ns VrampPWMR ampp-p -65 A to 1mA95dBV/VGBWE rrorAmplifierGain-BandwidthProduct11 MHzIFBF eedbackPin BiasCurrentVFB= (OVP/UVPC onditionDurationto PGOODF alling)15 stPGDGHPGOODD eglitchHigh(minimumlowpulse)

7 12 sRPGOODPGOODP ulldownResistance102040 IPGOODLEAKPGOODL eakageCurrentVPGOOD= 5V1nALOGICVIHSYNCSYNCPin Pin Pin Hysteresis50110180mVIENEN Pin PullupCurrentVEN= 0V2 ATHERMALSHUTDOWNTTHERMSDT hermalShutdown165 CTTHERMSDHYST hermalShutdownHysteresis10 C-40 -20 020 40 60 80 100 (mA)JUNCTION TEMPERATURE ( C)IPVIN(mA)IAVINIPVIN-40 -20020 40 60 80 100 (V)JUNCTION TEMPERATURE ( C) + IAVIN(mA)INPUT VOLTAGE (V)02 4 68 10 129092949698100 Efficiency (%)OUTPUT CURRENT(A)VIN= 10 12808284868890929496 Efficiency (%)OUTPUT CURRENT(A)FSW= 500kHzFSW= 1 MHzFSW= 4 68 10 1280828486889092949698100 Efficiency (%)OUTPUT CURRENT(A)VOUT= MARCH2011 REVISEDJUNE2019 ProductFolderLinks: lm21212 -2 SubmitDocumentationFeedbackCopyright 2011 2019, :VVIN= 5 V, VOUT= V, L= H ( RDCR), CSS= 33 nF, fSW= 500 kHz (RADJ= ),TA= 25 C for efficiencycurves,loop gain plotsand waveforms,and TJ= 25 C for all EfficiencyFigure2.

8 EfficiencyVOUT= VFSW= 300 KHzInductorP/NSer2010-102 MLDF igure3. EfficiencyFigure4. Non-SwitchingIQTOTALvs VINF igure5. Non-SwitchingIAVINand IPVINvs TemperatureFigure6. VFBvs Temperature-40 -20020406080 100 1202345678910 RDSON(m )JUNCTION TEMPERATURE ( C)LOW SIDEHIGH SIDE-40 -20 0 20 40 60 80 100 120120124128132136140144148152156160 MINIMUM ON-TIME (nS)JUNCTION TEMPERATURE( C)-40 -20020 40 60 80 100 ,VUVP(V)JUNCTION TEMPERATURE ( C)VUVPVOVP-40 -20 0 20 40 60 80 100 1204042444648505254565860 SHUTDOWN CURRENT ISD( A)JUNCTION TEMPERATURE( C)-40 -20 020 40 60 80 100 (V)JUNCTION TEMPERATURE ( C)VENHYS(V)V IHENRV ENHYS-40 -20 020 40 60 80 100 (V)JUNCTION TEMPERATURE ( C)VUVLOHYS(mV)V UVLOV UVLOHYS8LM21212-2 SNVS715B MARCH2011 : lm21212 -2 SubmitDocumentationFeedbackCopyright 2011 2019,TexasInstrumentsIncorporatedTypical Characteristics(continued)Unlessotherwis especified.

9 VVIN= 5 V, VOUT= V, L= H ( RDCR), CSS= 33 nF, fSW= 500 kHz (RADJ= ),TA= 25 C for efficiencycurves,loop gain plotsand waveforms,and TJ= 25 C for all EnableThresholdand Hysteresisvs TemperatureFigure8. UVLOT hresholdand Hysteresisvs TemperatureFigure9. EnableLowCurrentvs TemperatureFigure10. OVP/UVPT hresholdvs TemperatureFigure11. MinimumOn-Timevs TemperatureFigure12. FET Resistancevs TemperatureVPGOOD (5V/Div)IL (10A/Div)VOUT (1V/Div)VOUT (500 mV/Div)VPGOOD (5V/Div)VTRACK (500 mV/Div)IOUT (10A/Div)VOUT (500 mV/Div)VPGOOD (5V/Div)VENABLE (5V/Div)IOUT (10A/Div)-40 -20020 40 60 80 100 LIMIT ICLR(A)AMBIENT TEMPERATURE ( C)VOUT (500 mV/Div)VPGOOD (5V/Div)VENABLE (5V/Div) MARCH2011 REVISEDJUNE2019 ProductFolderLinks: lm21212 -2 SubmitDocumentationFeedbackCopyright 2011 2019,TexasInstrumentsIncorporatedTypical Characteristics(continued)Unlessotherwis especified:VVIN= 5 V, VOUT= V, L= H ( RDCR), CSS= 33 nF, fSW= 500 kHz (RADJ= ),TA= 25 C for efficiencycurves,loop gain plotsand waveforms,and TJ= 25 C for all PeakCurrentLimitvs Temperature2 ms/DIVF igure14.

10 Start-upWithPrebiasedOutput200 s/DIVF igure15. Start-upWithSS/TRKOpenCircuit200 ms/DIVF igure16. Start-upWithAppliedTrackSignal10 s/DIVF igure17. OutputOvercurrentConditionControlLogicOv ertempOSCRAMPINTSSVREF+-AVINENFADJSS/TRK FBCOMPAGNDPGNDPGOODSWPVINPWM comparatorUVLOP recision enableUVPSDI limit lowIlimit +-+-+-+-+-EA+-+ MARCH2011 : lm21212 -2 SubmitDocumentationFeedbackCopyright 2011 2019,TexasInstrumentsIncorporated8 lm21212 -2switchingregulatorfeaturesall of the functionsnecessaryto implementan efficientlow voltagebuckregulatorusinga minimumnumberof is capableof supplyingup to 12 A of regulatorutilizesvoltagemodecontrolwith trailingedgemodulationto optimizestabilityand transientresponseoverthe devicecan operateat highswitchingfrequencyallowinguse of a smallinductorwhilestill achievinghigh precisioninternalvoltagereferenceallowst he outputto be set as low as.