User's Guide SNVA341A–April2008–RevisedApril2013 AN-1837 LM2738 Evaluation Board 1 Introduction TheLM2738demoboardisconfiguredtoconvert12Vinputto3.3Voutputat1.5Aloadcurrentusingthe LM2738X1.6MHzortheLM2738Y550kHzstepdownDC-DCregulator.ThetinylowprofileMSOP- PowerPAD-8andWSON-8packagesallowsthedemoboardtobemanufacturedusingjustoverone squareinchofa4-layerprintedcircuitboard. ThecircuitisconfiguredwiththeboostdiodeconnectedtoV ,andaccordingtothedatasheet,V OUT OUT mustnotexceedthemaximumoperatinglimitof5.5V+V usingthisconfiguration.Thiswillensurethat fD2 thevoltagebetweentheBoostandSWpins,V -V ,doesnotexceed5.5Vforproperoperation. BOOST SW PleaseseetheLM2738550kHz/1.6MHz1.5AStep-DownDC-DCSwitchingRegulator(SNVS556)data sheetformoreinformationregardingthisrequirement. Abillofmaterialsdescribesthepartsusedonthisdemoboard.Aschematicandlayouthavealsobeen includedbelowalongwithmeasuredperformancecharacteristics.Theschematicsattheendofthis documentshowhowtore-configurethisdemoboardforvariousinputandoutputconditionsasdiscussed intheLM2738550kHz/1.6MHz1.5AStep-DownDC-DCSwitchingRegulatorSNVS556datasheet.Short orleaveopentheindicatedconnectionasindicatedintheschematics.Theaboverestrictionsfortheinput voltagearevalidonlyforthedemoboardasshippedwiththedemoboardschematic(seeFigure1). 2 Operating Conditions V =12V IN V =3.3V O I =1.5A O Figure1.LM2738DemoBoardSchematic-V derivedfromV =3.3V,V =12V BOOST OUT IN Alltrademarksarethepropertyoftheirrespectiveowners. SNVA341A–April2008–RevisedApril2013 AN-1837LM2738EvaluationBoard 1 SubmitDocumentationFeedback Copyright©2008–2013,TexasInstrumentsIncorporated

OperatingConditions www.ti.com Figure2.EfficiencyvsLoadCurrent-V =12V,V =3.3V IN OUT Table1.BillofMaterialsX-Version(1.6MHz) PartID PartValue Manufacturer PartNumber PackageType C1,InputCap 10µF,25V,X7R TDK C3216X5R1E106 1206 C2,C5,OutputCap 22µF,10V,X5R TDK C3216X5R1A226 1206 C3(BoostCap),C4 0.1µF TDK C2012X7R1A104 0805 D2,BoostDiode 1V @100mADiode Diodes,Inc. BAT54WS-TP SOD-323 F R2,R3 10kΩ,1% Vishay CRCW12061002F 0805 LM2738 WSON-8 U1 1.5ABuckRegulator TexasInstruments LM2738 MSOP-PowerPAD-8 D1,CatchDiode 0.34V Schottky1.5A, Toshiba CRS08 - F 30VR L1 5.0µH,2.9A Coilcraft MSS7341-502NL - R1 31.6kΩ,1% Vishay CRCW12063162F 0805 R5 0Ω Vishay CRCW12060R00F 0805 D4,R4 OpenorNoLoad Table2.BillofMaterialsY-Version(550kHz) PartID PartValue Manufacturer PartNumber PackageType C1,InputCap 10µF,25V,X7R TDK C3216X5R1E106 1206 C2,C5,OutputCap 22µF,10V,X5R TDK C3216X5R1A226 1206 C3(BoostCap),C4 0.1µF TDK C2012X7R1A104 0805 D2,BoostDiode 1V @100mADiode Diodes,Inc. BAT54WS-TP SOD-323 F R2,R3 10kΩ,1% Vishay CRCW12061002F 0805 LM2738 WSON-8 U1 1.5ABuckRegulator TexasInstruments MSOP-PowerPAD- LM2738 8 D1,CatchDiode 0.34V Schottky1.5A, Toshiba CRS08 - F 30VR L1 10.0µH,2.0A Coilcraft MSS7341-103NL - R1 31.6kΩ,1% Vishay CRCW12063162F 0805 R5 0Ω Vishay CRCW12060R00F 0805 D4,R4 OpenorNoLoad 2 AN-1837LM2738EvaluationBoard SNVA341A–April2008–RevisedApril2013 SubmitDocumentationFeedback Copyright©2008–2013,TexasInstrumentsIncorporated

www.ti.com OperatingConditions SNVA341A–April2008–RevisedApril2013 AN-1837LM2738EvaluationBoard 3 SubmitDocumentationFeedback Copyright©2008–2013,TexasInstrumentsIncorporated

PCBLayout-WSON www.ti.com 3 PCB Layout - WSON Figure3.TopLayer 4 AN-1837LM2738EvaluationBoard SNVA341A–April2008–RevisedApril2013 SubmitDocumentationFeedback Copyright©2008–2013,TexasInstrumentsIncorporated

www.ti.com PCBLayout-WSON Figure4.InternalPlane-Layer2(GND) SNVA341A–April2008–RevisedApril2013 AN-1837LM2738EvaluationBoard 5 SubmitDocumentationFeedback Copyright©2008–2013,TexasInstrumentsIncorporated

PCBLayout-WSON www.ti.com Figure5.InternalPlane-Layer3(GND) 6 AN-1837LM2738EvaluationBoard SNVA341A–April2008–RevisedApril2013 SubmitDocumentationFeedback Copyright©2008–2013,TexasInstrumentsIncorporated

www.ti.com PCBLayout-WSON Figure6.BottomLayer SNVA341A–April2008–RevisedApril2013 AN-1837LM2738EvaluationBoard 7 SubmitDocumentationFeedback Copyright©2008–2013,TexasInstrumentsIncorporated

PCBLayout-MSOP-PowerPAD www.ti.com 4 PCB Layout - MSOP-PowerPAD Figure7.TopLayer 8 AN-1837LM2738EvaluationBoard SNVA341A–April2008–RevisedApril2013 SubmitDocumentationFeedback Copyright©2008–2013,TexasInstrumentsIncorporated

www.ti.com PCBLayout-MSOP-PowerPAD Figure8.InternalPlane-Layer2(GND) SNVA341A–April2008–RevisedApril2013 AN-1837LM2738EvaluationBoard 9 SubmitDocumentationFeedback Copyright©2008–2013,TexasInstrumentsIncorporated

PCBLayout-MSOP-PowerPAD www.ti.com Figure9.InternalPlane-Layer3(GND) 10 AN-1837LM2738EvaluationBoard SNVA341A–April2008–RevisedApril2013 SubmitDocumentationFeedback Copyright©2008–2013,TexasInstrumentsIncorporated

www.ti.com AdditionalCircuitConfigurationSchematics Figure10.BottomLayer 5 Additional Circuit Configuration Schematics Figure11.V derivedfromV =5V,forV =1.5V BOOST IN OUT SNVA341A–April2008–RevisedApril2013 AN-1837LM2738EvaluationBoard 11 SubmitDocumentationFeedback Copyright©2008–2013,TexasInstrumentsIncorporated

AdditionalCircuitConfigurationSchematics www.ti.com Table3.BillofMaterialsX-Version(1.6MHz) PartID PartValue Manufacturer PartNumber PackageType C1,InputCap 10µF,25V,X7R TDK C3216X5R1E106 1206 C2,OutputCap 22µF,6.3V,X5R TDK C3216X5R0J2266 1206 C3(BoostCap),C4 0.1µF TDK C2012X7R1A104 0805 D2,BoostDiode 1V @100mADiode Diodes,Inc. BAT54WS-TP SOD-323 F R2,R3 10kΩ,1% Vishay CRCW12061002F 0805 LM2738 WSON-8 U1 1.5ABuckRegulator TexasInstruments LM2738 MSOP-PowerPAD-8 D1,CatchDiode 0.34V Schottky1.5A,30V Toshiba CRS08 - F L1 2.2µH,1.9A Coilcraft MSS5131-222ML - R1 8.87kΩ,1% Vishay CRCW12068871F 0805 R4 0Ω Vishay CRCW12060R00F 0805 D4,R5,C5 OpenorNoLoad Table4.BillofMaterialsY-Version(550kHz) PartID PartValue Manufacturer PartNumber PackageType C1,InputCap 10µF,25V,X7R TDK C3216X5R1E106 1206 C2,C5,OutputCaps 22µF,6.3V,X5R TDK C3216X5R0J226 1206 C3(BoostCap),C4 0.1µF TDK C2012X7R1A104 0805 D2,BoostDiode 1V @100mADiode Diodes,Inc. BAT54WS-TP SOD-323 F R2,R3 10kΩ,1% Vishay CRCW12061002F 0805 LM2738 WSON-8 U1 1.5ABuckRegulator TexasInstruments LM2738 MSOP-PowerPAD-8 D1,CatchDiode 0.34V Schottky1.5A,30V Toshiba CRS08 - F L1 6.2µH,2.5A Coilcraft MSS7341-622NL - R1 8.87kΩ,1% Vishay CRCW12068871F 0805 R4 0Ω Vishay CRCW12060R00F 0805 D4,R5 OpenorNoLoad Figure12.V derivedfromV comingfromV =18V,V =1.5V BOOST SHUNT IN OUT 12 AN-1837LM2738EvaluationBoard SNVA341A–April2008–RevisedApril2013 SubmitDocumentationFeedback Copyright©2008–2013,TexasInstrumentsIncorporated

www.ti.com AdditionalCircuitConfigurationSchematics Table5.BillofMaterialsX-Version(1.6MHz) PartID PartValue Manufacturer PartNumber PackageType C1,InputCap 10µF,25V,X7R TDK C3216X5R1E106 1206 C2,C5,OutputCaps 22µF,6.3V,X5R TDK C3216X5R0J226 1206 C3(BoostCap),C4 0.1µF TDK C2012X7R1A104 0805 D2,BoostDiode 1V @100mADiode Diodes,Inc. BAT54WS-TP SOD-323 F D4,Zeneer 5.1V,200mW Diodes,Inc. BZX84C5V1W SOT-323 R2,R3 10kΩ,1% Vishay CRCW12061002F 0805 LM2738 WSON-8 U1 1.5ABuckRegulator TexasInstruments LM2738 MSOP-PowerPAD-8 D1,CatchDiode 0.34V Schottky1.5A,30V Toshiba CRS08 - F L1 2.7µH,1.76A TDK VLCF5020T-2R7N1R7 - R1 8.87kΩ,1% Vishay CRCW12068871F 0805 R4 4.12kΩ.1% Vishay CRCW12064121F 0805 R5 OpenorNoLoad Table6.BillofMaterialsY-Version(550kHz) PartID PartValue Manufacturer PartNumber PackageType C1,InputCap 10µF,25V,X7R TDK C3216X5R1E106 1206 C2,C5,OutputCaps 47µF,6.3V,X5R TDK C3216X5R0J476 1206 C3(BoostCap),C4 0.1µF TDK C2012X7R1A104 0805 D2,BoostDiode 1V @100mADiode Diodes,Inc. BAT54WS-TP SOD-323 F D4,Zeneer 5.1V,200mW Diodes,Inc. BZX84C5V1W SOT-323 R2,R3 10kΩ,1% Vishay CRCW12061002F 0805 LM2738 WSON-8 U1 1.5ABuckRegulator TexasInstruments LM2738 MSOP-PowerPAD-8 D1,CatchDiode 0.34V Schottky1.5A,30V Toshiba CRS08 - F L1 8.7µH,2.2A Coilcraft MSS7341-872NL - R1 8.87kΩ,1% Vishay CRCW12068871F 0805 R4 4.21kΩ,1% Vishay CRCW12064211F 0805 R5 OpenorNoLoad Figure13.V derivedfromSeriesZenerDiodefromV =15V,V =1.5V BOOST IN OUT SNVA341A–April2008–RevisedApril2013 AN-1837LM2738EvaluationBoard 13 SubmitDocumentationFeedback Copyright©2008–2013,TexasInstrumentsIncorporated

AdditionalCircuitConfigurationSchematics www.ti.com Table7.BillofMaterialsX-Version(1.6MHz) PartID PartValue Manufacturer PartNumber PackageType C1,InputCap 10µF,25V,X7R TDK C3216X5R1E106 1206 C2,C5,OutputCaps 22µF,6.3V,X5R TDK C3216X5R0J226 1206 C3(BoostCap) 0.1µF TDK C2012X7R1A104 0805 D2,BoostDiode 1V @100mADiode Diodes,Inc. BAT54WS-TP SOD-323 F R2,R3 10kΩ,1% Vishay CRCW12061002F 0805 LM2738 WSON-8 U1 1.5ABuckRegulator TexasInstruments LM2738 MSOP-PowerPAD-8 D1,CatchDiode 0.34V Schottky1.5A,30V Toshiba CRS08 - F L1 3.3µH,3.5A Coilcraft MSS7341-332NL - R1 8.87kΩ,1% Vishay CRCW12068871F 0805 R4 11V,200mW,Zener Vishay BZX384C11-V SOD-323 D4,R5,C4 OpenorNoLoad Table8.BillofMaterialsY-Version(550kHz) PartID PartValue Manufacturer PartNumber PackageType C1,InputCap 10µF,25V,X7R TDK C3216X5R1E106 1206 C2,C5,OutputCaps 47µF,6.3V,X5R TDK C3216X5R0J476 1206 C3(BoostCap) 0.1µF TDK C2012X7R1A104 0805 D2,BoostDiode 1V @100mADiode Diodes,Inc. BAT54WS-TP SOD-323 F R2,R3 10kΩ,1% Vishay CRCW12061002F 0805 LM2738 WSON-8 U1 1.5ABuckRegulator TexasInstruments LM2738 MSOP-PowerPAD-8 D1,CatchDiode 0.34V Schottky1.5A,30V Toshiba CRS08 - F L1 8.7µH,2.2A Coilcraft MSS7341-872NL - R1 8.87kΩ,1% Vishay CRCW12068871F 0805 R4 11V,200mW,Zener Vishay BZX384C11-V SOD-323 D4,R5,C4 OpenorNoLoad Figure14.V derivedfromSeriesZenerDiodefromV =9V,V =15V BOOST OUT IN 14 AN-1837LM2738EvaluationBoard SNVA341A–April2008–RevisedApril2013 SubmitDocumentationFeedback Copyright©2008–2013,TexasInstrumentsIncorporated

www.ti.com AdditionalCircuitConfigurationSchematics Table9.BillofMaterialsX-Version(1.6MHz) PartID PartValue Manufacturer PartNumber PackageType C1,InputCap 10µF,25V,X7R TDK C3216X5R1E106 1206 C2,OutputCap 22µF,10V,X5R TDK C3216X5R1A226 1206 C3(BoostCap),C4 0.1µF TDK C2012X7R1A104 0805 D2,BoostDiode 1V @100mADiode Diodes,Inc. BAT54WS-TP SOD-323 F R2,R3 10kΩ,1% Vishay CRCW12061002F 0805 LM2738 WSON-8 U1 1.5ABuckRegulator TexasInstruments LM2738 MSOP-PowerPAD-8 D1,CatchDiode 0.34V Schottky1.5A,30V Toshiba CRS08 - F L1 6.2µH,2.5A Coilcraft MSS7341-622NL - R1 102kΩ,1% Vishay CRCW1206123F 0805 R5 4.3V,200mW,Zener Vishay BZX384C4V3-V SOD-323 D4,R4 OpenorNoLoad Table10.BillofMaterialsY-Version(550kHz) PartID PartValue Manufacturer PartNumber PackageType C1,InputCap 10µF,25V,X7R TDK C3216X5R1E106 1206 C2,OutputCap 22µF,10V,X5R TDK C3216X5R1A226 1206 C3(BoostCap),C4 0.1µF TDK C2012X7R1A104 0805 D2,BoostDiode 1V @100mADiode Diodes,Inc. BAT54WS-TP SOD-323 F R2,R3 10kΩ,1% Vishay CRCW12061002F 0805 LM2738 WSON-8 U1 1.5ABuckRegulator TexasInstruments LM2738 MSOP-PowerPAD-8 D1,CatchDiode 0.34V Schottky1.5A,30V Toshiba CRS08 - F L1 5.0µH,2.9A Coilcraft MSS7341-502NL - R1 102kΩ,1% Vishay CRCW12061023F 0805 R5 4.3V,200mW,Zener Vishay BZX384C4V3-V SOD-323 D4,R4 OpenorNoLoad SNVA341A–April2008–RevisedApril2013 AN-1837LM2738EvaluationBoard 15 SubmitDocumentationFeedback Copyright©2008–2013,TexasInstrumentsIncorporated

IMPORTANTNOTICE TexasInstrumentsIncorporatedanditssubsidiaries(TI)reservetherighttomakecorrections,enhancements,improvementsandother changestoitssemiconductorproductsandservicesperJESD46,latestissue,andtodiscontinueanyproductorserviceperJESD48,latest issue.Buyersshouldobtainthelatestrelevantinformationbeforeplacingordersandshouldverifythatsuchinformationiscurrentand complete.Allsemiconductorproducts(alsoreferredtohereinas“components”)aresoldsubjecttoTI’stermsandconditionsofsale suppliedatthetimeoforderacknowledgment. TIwarrantsperformanceofitscomponentstothespecificationsapplicableatthetimeofsale,inaccordancewiththewarrantyinTI’sterms andconditionsofsaleofsemiconductorproducts.TestingandotherqualitycontroltechniquesareusedtotheextentTIdeemsnecessary tosupportthiswarranty.Exceptwheremandatedbyapplicablelaw,testingofallparametersofeachcomponentisnotnecessarily performed. TIassumesnoliabilityforapplicationsassistanceorthedesignofBuyers’products.Buyersareresponsiblefortheirproductsand applicationsusingTIcomponents.TominimizetherisksassociatedwithBuyers’productsandapplications,Buyersshouldprovide adequatedesignandoperatingsafeguards. TIdoesnotwarrantorrepresentthatanylicense,eitherexpressorimplied,isgrantedunderanypatentright,copyright,maskworkright,or otherintellectualpropertyrightrelatingtoanycombination,machine,orprocessinwhichTIcomponentsorservicesareused.Information publishedbyTIregardingthird-partyproductsorservicesdoesnotconstitutealicensetousesuchproductsorservicesorawarrantyor endorsementthereof.Useofsuchinformationmayrequirealicensefromathirdpartyunderthepatentsorotherintellectualpropertyofthe thirdparty,oralicensefromTIunderthepatentsorotherintellectualpropertyofTI. ReproductionofsignificantportionsofTIinformationinTIdatabooksordatasheetsispermissibleonlyifreproductioniswithoutalteration andisaccompaniedbyallassociatedwarranties,conditions,limitations,andnotices.TIisnotresponsibleorliableforsuchaltered documentation.Informationofthirdpartiesmaybesubjecttoadditionalrestrictions. ResaleofTIcomponentsorserviceswithstatementsdifferentfromorbeyondtheparametersstatedbyTIforthatcomponentorservice voidsallexpressandanyimpliedwarrantiesfortheassociatedTIcomponentorserviceandisanunfairanddeceptivebusinesspractice. TIisnotresponsibleorliableforanysuchstatements. Buyeracknowledgesandagreesthatitissolelyresponsibleforcompliancewithalllegal,regulatoryandsafety-relatedrequirements concerningitsproducts,andanyuseofTIcomponentsinitsapplications,notwithstandinganyapplications-relatedinformationorsupport thatmaybeprovidedbyTI.Buyerrepresentsandagreesthatithasallthenecessaryexpertisetocreateandimplementsafeguardswhich anticipatedangerousconsequencesoffailures,monitorfailuresandtheirconsequences,lessenthelikelihoodoffailuresthatmightcause harmandtakeappropriateremedialactions.BuyerwillfullyindemnifyTIanditsrepresentativesagainstanydamagesarisingoutoftheuse ofanyTIcomponentsinsafety-criticalapplications. Insomecases,TIcomponentsmaybepromotedspecificallytofacilitatesafety-relatedapplications.Withsuchcomponents,TI’sgoalisto helpenablecustomerstodesignandcreatetheirownend-productsolutionsthatmeetapplicablefunctionalsafetystandardsand requirements.Nonetheless,suchcomponentsaresubjecttotheseterms. NoTIcomponentsareauthorizedforuseinFDAClassIII(orsimilarlife-criticalmedicalequipment)unlessauthorizedofficersoftheparties haveexecutedaspecialagreementspecificallygoverningsuchuse. OnlythoseTIcomponentswhichTIhasspecificallydesignatedasmilitarygradeor“enhancedplastic”aredesignedandintendedforusein military/aerospaceapplicationsorenvironments.BuyeracknowledgesandagreesthatanymilitaryoraerospaceuseofTIcomponents whichhavenotbeensodesignatedissolelyattheBuyer'srisk,andthatBuyerissolelyresponsibleforcompliancewithalllegaland regulatoryrequirementsinconnectionwithsuchuse. TIhasspecificallydesignatedcertaincomponentsasmeetingISO/TS16949requirements,mainlyforautomotiveuse.Inanycaseofuseof non-designatedproducts,TIwillnotberesponsibleforanyfailuretomeetISO/TS16949. Products Applications Audio www.ti.com/audio AutomotiveandTransportation www.ti.com/automotive Amplifiers amplifier.ti.com CommunicationsandTelecom www.ti.com/communications DataConverters dataconverter.ti.com ComputersandPeripherals www.ti.com/computers DLP®Products www.dlp.com ConsumerElectronics www.ti.com/consumer-apps DSP dsp.ti.com EnergyandLighting www.ti.com/energy ClocksandTimers www.ti.com/clocks Industrial www.ti.com/industrial Interface interface.ti.com Medical www.ti.com/medical Logic logic.ti.com Security www.ti.com/security PowerMgmt power.ti.com Space,AvionicsandDefense www.ti.com/space-avionics-defense Microcontrollers microcontroller.ti.com VideoandImaging www.ti.com/video RFID www.ti-rfid.com OMAPApplicationsProcessors www.ti.com/omap TIE2ECommunity e2e.ti.com WirelessConnectivity www.ti.com/wirelessconnectivity MailingAddress:TexasInstruments,PostOfficeBox655303,Dallas,Texas75265 Copyright©2013,TexasInstrumentsIncorporated