User's Guide SLVU340–October2009 TL4242EVM-543 The TL4242EVM-543 evaluation module is designed to evaluate the TL4242 integrated circuit in a typical LED application. This user's guide provides a connector and test point description, the schematic of the EVM,billofmaterials,andboardlayout. Contents 1 Introduction .................................................................................................................. 2 1.1 Description .......................................................................................................... 2 1.2 Applications ......................................................................................................... 2 1.3 Features ............................................................................................................. 2 2 TL4242EVM-543Schematic ............................................................................................... 2 3 ConnectorandTestPointDescriptions .................................................................................. 3 3.1 EnableJumpers/Switches ........................................................................................ 3 4 TL4242EVMAssemblyDrawingsandLayout ........................................................................... 4 4.1 BoardDesignandLayout ......................................................................................... 4 4.2 PowerDissipationandThermalConsiderations ............................................................... 6 5 BillofMaterials .............................................................................................................. 7 ListofFigures 1 TL4242EVM-543Schematic............................................................................................... 3 2 TL4242EVM-543ComponentPlacement(ViewedFromTop)........................................................ 5 3 TL4242EVM-543TopCopper(ViewedFromTop)..................................................................... 5 4 TL4242EVM-543BottomCopper(ViewedFromBottom)............................................................. 5 5 TL4242EVM-543MaximumVinvsLEDCurrent ....................................................................... 7 6 TL4242EVM-543TopInfraredatV =12V,I =357mA(ViewedFromTop)................................... 7 in LED ListofTables 1 BillofMaterials.............................................................................................................. 7 SLVU340–October2009 TL4242EVM-543 1 SubmitDocumentationFeedback Copyright©2009,TexasInstrumentsIncorporated

Introduction www.ti.com 1 Introduction TexasInstrumentsTL4242EVM-543evaluationmodulecontainsaTL4242integratedcircuit(IC), supportingpassivecomponentsandthreeOSRAMLEDsinseries.ThepurposeofthisEVMistofacilitate evaluationoftheTL4242inatypicalLEDapplication. 1.1 Description TheTexasInstrumentsTL4242EVM-543evaluationmodule(EVM)helpsdesignersevaluatetheoperation andperformanceoftheTL4242.Thisdeviceisanintegrated,adjustable,constant-currentsource,driving loadsupto500mA.Theoutputcurrentcanbeadjustedviaanexternalresistor.Thedeviceisdesignedto supplyhigh-powerLEDsunderthesevereconditionsofautomotiveapplicationsandarchitecturallighting. TheTL4242ICiscapableofoperatingatinputvoltagesupto42V.Duetothermalconsiderations,the EVMmaynotallowaninputvoltagethishigh.Section4.2providesmoredetails. 1.2 Applications • Automotiveapplications • Architecturallighting 1.3 Features • Adjustableconstantcurrentupto500mA(±5%) • Wideinputvoltagerangeupto42V • Lowdropvoltage • Open-loaddetection • Overtemperatureprotection • Short-circuitproof • Reverse-polarityproof • Widetemperaturerange:–40°Cto150°C • AdditionalkeyfeaturesoftheEVM(notICfeatures) – AdjustableLEDcurrent 2 TL4242EVM-543 Schematic Figure1.TL4242EVM-543Schematic 2 TL4242EVM-543 SLVU340–October2009 SubmitDocumentationFeedback Copyright©2009,TexasInstrumentsIncorporated

www.ti.com ConnectorandTestPointDescriptions 3 Connector and Test Point Descriptions 3.1 Enable Jumpers/Switches 3.1.1 J1–V IN Thisisthepositiveinputsupplyvoltage. 3.1.2 J2–GND Thisisthereturnconnectiontotheinputpowersupply. 3.1.3 J3–VLED+ WhenusingexternalLEDs,connectanodetoVLED+. 3.1.4 J4–PWM Thisisahigh-impedanceinputtotheTL4242IC.Whenthissignalislogichigh,theoutputisenabled. Whenthissignalislogiclow,theoutputisdisabled.Leavingthepinopendefaultsittologichigh. 3.1.5 J5–ST ThestatusoutputoftheLEDdriver(ST)detectsanopen-loadcondition,enablingsupervisionofcorrect LEDoperation. 3.1.6 J6–GND ThisisthereturnconnectionforPWMandSTpins. 3.1.7 J7–VLED– WhenusingexternalLEDs,connectcathodetoVLED–. 3.1.8 JP1– DisableD3 Wheninstalled,D3isshorted,allowingtheusertoevaluateperformancewithtwoLEDs. 3.1.9 JP2– OpenLED Whenremoved,JP2allowstheusertoevaluateexternalLEDs. 3.1.10 JP3– Bright/Dim ThisjumperswitchesbetweenthebrightanddimsettingsoftheLEDs.Whenshorted,thebrightsettingis activated. SLVU340–October2009 TL4242EVM-543 3 SubmitDocumentationFeedback Copyright©2009,TexasInstrumentsIncorporated

TL4242EVMAssemblyDrawingsandLayout www.ti.com 4 TL4242EVM Assembly Drawings and Layout 4.1 Board Design and Layout Thefollowingfigures(Figure2throughFigure4)showthedesignoftheTL4242EVM-543printed-circuit board(PCB).TheEVMhasbeendesignedusingatwo-layer,2-oz,copper-cladcircuitboard2.75in.× 3.2 in.withallcomponentsinanactiveareaonthetopsideandallactivetracestothetopandbottomlayers toallowtheusertoeasilyview,probe,andevaluatetheTL4242controlICinapracticaldouble-sided application.MovingcomponentstobothsidesofthePCBorusingadditionalinternallayerscanoffer additionalsizereductionforspaceconstrainedsystems. Figure2.TL4242EVM-543ComponentPlacement(ViewedFromTop) 4 TL4242EVM-543 SLVU340–October2009 SubmitDocumentationFeedback Copyright©2009,TexasInstrumentsIncorporated

www.ti.com TL4242EVMAssemblyDrawingsandLayout Figure3.TL4242EVM-543TopCopper(ViewedFromTop) Figure4.TL4242EVM-543BottomCopper(ViewedFromBottom) SLVU340–October2009 TL4242EVM-543 5 SubmitDocumentationFeedback Copyright©2009,TexasInstrumentsIncorporated

TL4242EVMAssemblyDrawingsandLayout www.ti.com 4.2 Power Dissipation and Thermal Considerations Figure6illustratesthethermalperformanceoftheTL4242EVM-543at357-mAoutputcurrentand12-V input.Undertheseconditions,themaximumtemperatureontheEVMis58.4°CattheICjunction.The powerdissipationoftheICisdescribedbyEquation1. P = [Vin - n ´ V - V ] ´ I ´ D+V ´ I IC LED REF LEDs in q (1) Where: n =NumberofLEDs V =VoltagedropacrossoneLED LED V =Referencevoltage,typically177mV REF D =Dutycycle(0-1)ofthePWMsignalappliedtoJ4 I =TL4242quiescentcurrent q Inordertomanagethepowerdissipation,thevoltagedrop,(V –n ×V – V ),oftheICneedstobe in LED REF controlled,especiallyathighcurrents.Figure5illustratesthemaximuminputvoltagesatvariousLED currentstolimittheICjunctiontemperatureto140°C.Ifinputvoltagesgreaterthanthesearedesired,the customercanaddexternalLEDstoreducethevoltagedropacrosstheIC.Anotheroptionistoincorporate aheat-sinkingmechanismtotheEVM. 45 40 35 T = 140°C J V x) - 30 a m e ( 25 g a Volt 20 ut p n 15 - I VI 10 5 0 0 50 100 150 200 250 300 350 400 450 500 I Current - mA LED Figure5.TL4242EVM-543MaximumVinvsLEDCurrent 6 TL4242EVM-543 SLVU340–October2009 SubmitDocumentationFeedback Copyright©2009,TexasInstrumentsIncorporated

www.ti.com BillofMaterials Figure6.TL4242EVM-543TopInfraredatV =12V,I =357mA(ViewedFromTop) in LED 5 Bill of Materials Table1.BillofMaterials Qty RefDes Value Description Size MFR PartNumber 1 C1 100nF Capacitor,Ceramic,LowInductance,50V, 0603 Std Std X5R,20% 1 C2 47nF Capacitor,Ceramic,LowInductance,16V, 0603 Std Std X5R,10% 3 D1,D2,D3 LW Diode,LEDWhite,500-mA,1x000-mcd 0.244×0.441 Osram LW W5SM-xxxx-5K8L in. W5SM-xxxx-5K8L 7 J1-J7 PEC02SAAN Header,2pin,100milspacing 0.100in.×2 Sullins PEC02SAAN 3 JP1,JP2, PEC02SAAN Header,2pin,100milspacing 0.100in.×2 Sullins PEC02SAAN JP3 1 R1 10k Resistor,Chip,1/16W,1% 0603 Std Std 1 R2 3.3 Resistor,Chip,1/16W,1% 0603 Std Std 1 R3 0.56 Resistor,Chip,1/16W,1% 0603 Std Std 1 U1 TL4242DRJ IC,Adj.LEDDriver WSON TI Tl4242DRJ SLVU340–October2009 TL4242EVM-543 7 SubmitDocumentationFeedback Copyright©2009,TexasInstrumentsIncorporated

EVALUATIONBOARD/KITIMPORTANTNOTICE TexasInstruments(TI)providestheenclosedproduct(s)underthefollowingconditions: Thisevaluationboard/kitisintendedforuseforENGINEERINGDEVELOPMENT,DEMONSTRATION,OREVALUATIONPURPOSES ONLYandisnotconsideredbyTItobeafinishedend-productfitforgeneralconsumeruse.Personshandlingtheproduct(s)musthave electronicstrainingandobservegoodengineeringpracticestandards.Assuch,thegoodsbeingprovidedarenotintendedtobecomplete intermsofrequireddesign-,marketing-,and/ormanufacturing-relatedprotectiveconsiderations,includingproductsafetyandenvironmental measurestypicallyfoundinendproductsthatincorporatesuchsemiconductorcomponentsorcircuitboards.Thisevaluationboard/kitdoes notfallwithinthescopeoftheEuropeanUniondirectivesregardingelectromagneticcompatibility,restrictedsubstances(RoHS),recycling (WEEE),FCC,CEorUL,andthereforemaynotmeetthetechnicalrequirementsofthesedirectivesorotherrelateddirectives. Shouldthisevaluationboard/kitnotmeetthespecificationsindicatedintheUser’sGuide,theboard/kitmaybereturnedwithin30daysfrom thedateofdeliveryforafullrefund.THEFOREGOINGWARRANTYISTHEEXCLUSIVEWARRANTYMADEBYSELLERTOBUYER ANDISINLIEUOFALLOTHERWARRANTIES,EXPRESSED,IMPLIED,ORSTATUTORY,INCLUDINGANYWARRANTYOF MERCHANTABILITYORFITNESSFORANYPARTICULARPURPOSE. Theuserassumesallresponsibilityandliabilityforproperandsafehandlingofthegoods.Further,theuserindemnifiesTIfromallclaims arisingfromthehandlingoruseofthegoods.Duetotheopenconstructionoftheproduct,itistheuser’sresponsibilitytotakeanyandall appropriateprecautionswithregardtoelectrostaticdischarge. EXCEPTTOTHEEXTENTOFTHEINDEMNITYSETFORTHABOVE,NEITHERPARTYSHALLBELIABLETOTHEOTHERFORANY INDIRECT,SPECIAL,INCIDENTAL,ORCONSEQUENTIALDAMAGES. TIcurrentlydealswithavarietyofcustomersforproducts,andthereforeourarrangementwiththeuserisnotexclusive. TIassumesnoliabilityforapplicationsassistance,customerproductdesign,softwareperformance,orinfringementofpatentsor servicesdescribedherein. PleasereadtheUser’sGuideand,specifically,theWarningsandRestrictionsnoticeintheUser’sGuidepriortohandlingtheproduct.This noticecontainsimportantsafetyinformationabouttemperaturesandvoltages.ForadditionalinformationonTI’senvironmentaland/or safetyprograms,pleasecontacttheTIapplicationengineerorvisitwww.ti.com/esh. NolicenseisgrantedunderanypatentrightorotherintellectualpropertyrightofTIcoveringorrelatingtoanymachine,process,or combinationinwhichsuchTIproductsorservicesmightbeorareused. FCCWarning Thisevaluationboard/kitisintendedforuseforENGINEERINGDEVELOPMENT,DEMONSTRATION,OREVALUATIONPURPOSES ONLYandisnotconsideredbyTItobeafinishedend-productfitforgeneralconsumeruse.Itgenerates,uses,andcanradiateradio frequencyenergyandhasnotbeentestedforcompliancewiththelimitsofcomputingdevicespursuanttopart15ofFCCrules,whichare designedtoprovidereasonableprotectionagainstradiofrequencyinterference.Operationofthisequipmentinotherenvironmentsmay causeinterferencewithradiocommunications,inwhichcasetheuserathisownexpensewillberequiredtotakewhatevermeasuresmay berequiredtocorrectthisinterference. EVMWARNINGSANDRESTRICTIONS ItisimportanttooperatethisEVMwithintheinputvoltagerangeof2.9Vto15V.Maximumoutputvoltageis42V. Exceedingthespecifiedinputrangemaycauseunexpectedoperationand/orirreversibledamagetotheEVM.Iftherearequestions concerningtheinputrange,pleasecontactaTIfieldrepresentativepriortoconnectingtheinputpower. TheEVMprintedcircuitboardgetsveryhotduringoperation.UsecareinhandlingduringandafterLEDoperation.WLEDsareverybright; protectiveeyewearisrecommended. Applyingloadsoutsideofthespecifiedoutputrangemayresultinunintendedoperationand/orpossiblepermanentdamagetotheEVM. PleaseconsulttheEVMUser'sGuidepriortoconnectinganyloadtotheEVMoutput.Ifthereisuncertaintyastotheloadspecification, pleasecontactaTIfieldrepresentative. Duringnormaloperation,somecircuitcomponentsmayhavecasetemperaturesgreaterthan160°C.TheEVMisdesignedtooperate properlywithcertaincomponentsabove160°Caslongastheinputandoutputrangesaremaintained.Thesecomponentsincludebutare notlimitedtolinearregulators,switchingtransistors,passtransistors,andcurrentsenseresistors.Thesetypesofdevicescanbeidentified usingtheEVMschematiclocatedintheEVMUser'sGuide.Whenplacingmeasurementprobesnearthesedevicesduringoperation, pleasebeawarethatthesedevicesmaybeverywarmtothetouch. MailingAddress:TexasInstruments,PostOfficeBox655303,Dallas,Texas75265 Copyright©2009,TexasInstrumentsIncorporated

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