Interleaved PFC technology bring up low ripple and

ProprietaryInformation1InterleavedPFCtechnologybringuplowrippleandhighefficiencyTonyHuang黄福恩TexasInstrumentSept12,2007ProprietaryInformation2PresentationOutlineØIntroductiontoInterleavedtransitionmodePFCØComparisontosingle-channelCCMPFCØComparisontoso-called“master/slave”architectureØInterleavetechnologybenefitus.ØRipplecancellationtodrivelowersystemcostØImprovedefficiencyviaenhancedphasemanagementtodrivehighersystemperformanceØContinuousTransitionModeoperationminimizesswitchinglossesassociatedwithMOSFETjunctioncapacitors(resultofDCMoperation)ØTIInterleavesolution:UCC28060ØFastertransientresponseviaslewratecomparatorØ“FailSafe”OVPpintoprovideadditionalsystemsafetyØImplementationofcurrentlimitingdriveslowersystemcosts,improvedreliabilityandhigherefficiencyØAdditionalBackupMaterialProprietaryInformation3InterleavedtransitionmodePFC:HighPerformanceatLowSystemCostProprietaryInformation4InterleavedPFCConceptreducedinputcurrentrippleDMfiltercanbereducedDistributedmagneticsImprovedthermalmanagementReducedoutputcurrentrippleBulkcapacitorsizecanbereducedphasemanagementispossibleImprovedpartialloadefficiencyØInterleavedPFCbecomesanattractivesolutionforpowersupplyindustryØDebateturningtoimplementationmethodProprietaryInformation5ØNodiodereverserecoveryØLessswitchinglossØLessEMINoiseØ25%SizereductionininductorsizeduetotransitionmodeoperationØ26.5%SizereductioninoutputcapacitorduetoripplecurrentcancellationØSimilarEMIfiltersizebecauseofinterleavingØPhasemanagementimprovespartialloadefficiency(typically5%)ØBetterthermalManagementandimprovedReliabilityduetotwophaseswithlowercurrentoperationComparingPerformancewithCCMPFCProprietaryInformation6MethodsofInterleavingTMPFCMaster-slavemethodNaturalInterleavingØSimplecontrolmethodifdonediscretelyØMasterchanneloperatesattransitionmodeØSlavechanneloperatesatDCMØNon-optimalphaseshiftØComplexcontrolifdonediscretely(simplifiedwithuseofTI’sUCC28060!)ØBothchanneloperateattransitionmode(minimizesswitchinglosses!)ØOptimizedphaseshift(minimizesripplecurrent!)ProprietaryInformation7NormalizedRippleCurrentNormalizedInputRippleCurrentInputRippleCancellationØComparingwithMasterSlavesolution,Naturalinterleavingcanfurtherreduceripplecurrentby50%ProprietaryInformation8InputRippleCancellation100Vinput,600WoutputØSimulationresultsverifiesbetterperformanceofNaturalinterleavingsolutionMaster-slaveNaturalinterleavingProprietaryInformation9OtherConsiderationsØSmallerinductorisrequiredforslavechannel,twodifferentinductorsarerequiredØHigherInventorycostsandpossiblemanufacturingriskØtwodifferentinductorsmaketheslavechannelalwaysoperateatDCMmode.ØhigherswitchinglossØTopreventslavechannelfallingintoCCMoperation,currentsharingisworseComparingwithNaturalInterleavingSolutionProprietaryInformation10IntroducingTI’sUCC28060:TheIndustry’sOnlyNaturalInterleavingSolutionProprietaryInformation11UCC28060Features&BenefitsNaturalInterleavingfromTIfeaturing:•FlexiblePhaseManagementtofacilitate80+andEnergyStardesigns•FailSafeOVPwithdualpathswhichpreventanyvoltageloopfailurefromcausinganoutputovervoltagecondition•SensorlessCurrentShapingtosimplifyboardlayoutandimproveefficiency•In-rushSafeCurrentLimitingtopreventMOSFETconductionduringin-rushandeliminatereverserecoveryeventsinoutputrectifiers.ProprietaryInformation12NaturalInterleaving:Whatisit?Phase-IcurrentPhase-IIcurrentPhase-IgatePhase-IIgatePhaseerror50%dutyProprietaryInformation13NaturalInterleaving:Whatbenefitsdoesitdeliver?qSystemFeatures§Stableoperationoverwidedynamicrange§Matchedcurrentsharingwithmatchedinductors§Averagestwo-channelnaturalfrequencies§Realize180-degreephaseshift§TransitionmodeoperationforbothchannelsqEndBenefitsüLowersystemcostthankstoripplecancellationüImprovedsystemefficiencyüMinimizedswitchinglossesProprietaryInformation14CurrentRippleCancellationPhaseAPhaseBTotalØ180phaseerrorandtransitionmodeoperationcanberealizedforwholelinecycle2A/div2mS/divProprietaryInformation15Ripplecancellationeffects50%DutyCycleØ180phaseerrorandtransitionmodeoperationcanberealizedforwholelinecyclePhaseAPhaseBTotalProprietaryInformation16RipplecancellationeffectsLowerPartofLineVoltageØ180phaseerrorandtransitionmodeoperationcanberealizedforwholelinecyclePhaseAPhaseBTotalProprietaryInformation17RipplecancellationeffectsZeroCrossingØ180phaseerrorandtransitionmodeoperationcanberealizedforwholelinecyclePhaseAPhaseBTotalProprietaryInformation18RipplecancellationeffectsPeakoftheLineØ180phaseerrorandtransitionmodeoperationcanberealizedforwholelinecyclePhaseAPhaseBTotalProprietaryInformation19HousekeepingandProtectionFeaturesØEnhancedphasemanagementØOutputvoltagesensingØImprovedtransientresponseØOutputovervoltageprotectionwithfail-safepinØOpenloopprotectionØCommunicationwithdownstreamDC/DCconverterØInputvoltagesensingØBrownoutprotectionØInputrangedetectØOvercurrentprotectionProprietaryInformation20UCC28060ErrorAmplifierØTransconductanceamplifier,VSENSEpinproportionaltooutputvoltageØSimplifiesoutputprotectionfunctionsØOpenLoopØOvervoltageProprietaryInformation21ImprovedTransient