TI UCC28810中小功率LED照明应用方案.docx

TI UCC28810中小功率LED照明应用方案.docx

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TIUCC28810中小功率LED照明应用方案

TI公司的UCC28810和UCC28811是中小功率通用led照明电源控制器,具有功率因素修正（PFC）和EMC兼容特性.设计用于工作在临界导通模式的反激,降压或升压转换器.UCC28810/1集成了用于反馈误差处理的跨导电压放大器,用来产生正比于输入电压的电流指令的电流基准发生器,电流检测（PWM）比较器,PWM逻辑和用来驱动外接FET的图腾柱驱动器.此外,控制器还提供峰值电流限制,重起定时器,过压保护（OVP）以及使能等.UCC28810和UCC28811广泛用在交流输入HBLED照明,工业,商业和住宅区照明以及户外照明如路灯,停车场,建筑物和装饰性LED照明等.本文介绍了UCC28810和UCC28811的主要特性,方框图,简化应用电路图,25WPFC反激转换器参考设计以及PR788100WAC/DCLED电流驱动器参考设计和元件列表.

TheUCC28810andUCC28811aregenerallightingpowercontrollersforlowtomediumpowerlumensapplicationsrequiringpowerfactorcorrectionandEMCcompliance.Itisdesignedforcontrollingaflyback,buckorboostconverteroperatingincriticalconductionmode.Itfeaturesatransconductancevoltageamplifierforfeedbackerrorprocessing,asimplecurrentreferencegeneratorforgeneratingacurrentcommandproportionaltotheinputvoltage,acurrent-sense（PWM）comparator,PWMlogicandatotem-poledriverfordrivinganexternalFET.

Inthecriticalconductionmodeoperation,thePWMcircuitissELf-oscillatingwiththeturn-onbeinggovernedbyatransformerzeroenergydetector（TZEpin）andtheturn-offbeinggovernedbythecurrentsensecomparator.Additionally,thecontrollerprovidesfeaturessuchaspeakcurrentlimit,restarttimer,overvoltageprotection（OVP）,andenable.

Theefficientsystemperformanceisattainedbyincorporationofzeropowerdetectfunctionwhichallowsthecontrolleroutputtoshutdownatlightloadconditionswithoutrunningintoovervoltage.Thedevicealsofeaturesaninnovativeslewrateenhancementcircuitwhichimprovesthelargesignaltransientperformanceofthevoltageerroramplifier.Thelowstart-upandoperatingcurrentsofthedeviceresultinlowpowerconsumptionandeaseofstart-up.Thehighly-accurateinternalbandgapreferenceleadstotightregulationoftheoutputvoltageinnormalandOVPconditions,resultinginhighersystemreliability.Theenablecomparatorensuresthatthecontrollerisoffifthefeedbacksensepathisbrokenoriftheinputvoltageisverylow.

TherearetwokeyparametricdifferencesbetweenUCC28810andUCC28811,theUVLOturn-onthresholdandthegMamplifiersourcecurrent.TheUVLOturn-onthresholdoftheUCC28810is15.8VandfortheUCC28811itis12.5V.ThegMamplifiersourcecurrentforUCC28810istypically1.3mA,andfortheUCC28811itis300µA.ThehigherUVLOturn-onthresholdoftheUCC28810allowsquickerandeasierstart-upwithasmallerVDDcapacitancewhilethelowerUVLOturn-onthresholdofUCC28811allowsoperationofthecriticalconductionmodecontrollertobeeasilycontrolledbythedownstreamPWMcontrollerintwo-stagepowerconverters.TheUCC28810gMamplifieralsoprovidesafull1.3-mAtypicalsourcecurrentforfasterstart-upandimprovedtransientresponsewhentheoutputisloweitheratstart-uporduringtransientconditions.TheUCC28811issuitableforapplicationssuchasstreetlightsandlargerarealuminaireswhereatwo-stagepowerconversionisneeded.TheUCC28810issuitableforapplicationssuchascommercialorresidentialretrofitluminaireswherethereisnodown-streamPWMconversionandtheadvantagesofsmallerVDDcapacitorandimprovedtransientresponsecanberealized.

Devicesareavailableintheindustrialtemperaturerangeof–40℃to105℃.Packageofferingisan8-pinSOIC（D）package.

UCC28810/1主要特性:

TransitionModeControllerforLowImplementationCostofACInputLEDLightingApplications 

ImplementsSingleStagePowerFactorCorrectedLEDDriver 

EnhancedTransientResponseWithSlew-RateComparator 

InterfaceswithTraditionalWallDimmers 

AccurateInternalVREFforTightOutputRegulation 

TwoUVLOOptions 

OvervoltageProtection（OVP）,Open-FeedbackProtectionandEnableCircuits 

±750-mAPeakGateDriveCurrent 

LowStart-UpandOperatingCurrents 

Lead（Pb）-FreePackages 

UCC28810/1应用:

ACInputGeneralLightingApplicationsUsingHBLEDs

Industrial,CommercialandResidentialLightingFixtures 

OutdoorLighting:

Street,Roadway,Parking,ConstructionandOrnamentalLEDLightingFixtures

图1.UCC28810方框图

图2.UCC28810简化应用电路图

图3.25WPFC反激转换器参考设计

ThePR788isa100-WofflineAC-to-DCLEDcurrentdriverwithpowerfactorcorrection.

ThisdesignisatwostageconverterdesignwithauniversalinputboostfollowerPFCstageprovidinga240-Vto400-VDCoutputandalow-sidebuckstageprovidingthecurrentsourcetopowertheLEDs.Thisconverterwasdesignedtosupportupto30high-brightnessLEDsinserieswithupto900-mAaveragecurrent.Thedesignincorporatesaninterfaceformicroprocessorcontroltoallowforshutdownintoalowpowermode（<0.5W）andPWMdimmingoftheLEDs.

图4.PR788100WAC/DCLED电流驱动器参考设计

图5.工作在CCM的低边降压转换器电路图

100WLED照明应用电路

A0.9-AConstantCurrentSupplywithPFCfor100-WLEDLightingApplications

TheUCC28810EVM-002isaconstantcurrentnon-isolatedpowersupplyforLEDlightingapplications.Itwillconvertuniversalmains（90VRMSto264VRMS）toa0.9-Aconstantcurrentintoa100-Wload.ThisevaluationmodulewillallowthecustomerevaluatetheUCC28810/11inatypicalLEDlightingapplication.

Theevaluationmoduleusesatwostageapproachtocontrollingtheoutputcurrent.

ThefirststageisatransitionmodePFCcircuit.Thisensuresthedesignmeetstheharmoniccurrentorpowerfactorrequirementssetoutbyvariousstandards,suchasEN61000-3-2.ThePFCcircuitconvertstheACinputtoaregulatedDCvoltage.ThisDCvoltagecanbeconfiguredinoneoftwoways.ThedefaultconfigurationofthemoduleisthatofaboostfollowertypePFC.TheboostfollowerPFCiswherethePFCregulatedoutputDCvoltagetrackstheACinputpeakvoltage.Thesecondconfigurationrequiresremovingsomecomponentsandchangingaresistorvalueseebelowformoredetails.Thissecond

configurationremovesthetrackingelementofthePFCcircuit.ThePFCDCoutputvoltagewillthenberegulatedtoafixedvalueintheregionof396VDC.

Thesecondstagealsousestransitionmodebutisconfiguredasabuckconverter.ItconvertsthePFCoutputvoltagetoafixedconstantcurrent.Thiscircuitiscapableofsupplying0.9Aintoa100-Wload.ItalsoacceptsPWMdimminginputs.AlternativelytheusercanusethePWMcircuitonthemoduletoseethedimmingfunction.

ThismodulewillworkwithmosthighbrightnessLED’s（HB-LED）thatoperatewith0.9Aandatotalstringvoltagedropofbetween55Vand110V.

主要特性:

90VRMSto264VRMSoperation

BoostFollowerorFixedOutputPFCStage

PFCDisable

OutputCurrentDisable

ExternalorInternalPWMDimming

典型应用:

ACInputGeneralLightingApplicationsUsingHB-LED’s

Industrial,CommercialandResidentialLightingFixtures

OutdoorLighting:

Street,Roadway,Parking,ConstructionandOrnamentalLEDLightingFixtures

图6.100WLED照明应用电路图

（1）

图7.100WLED照明应用电路图

（2）

材料列表: