LED背光技术的发展与挑战.ppt

LEDBLUDrivingandChallenge Outline LEDtoCCFLReplacementLEDbacklightbenefitsanalysisCCFL LEDmarketsharetrendSmall MiddleSizeDrivingTopologyLEDnotebook NetbookLEDmonitorLow enddisplayLEDTVDrivingTopologyOBLEDDriverRoadmapQ A TVProductsInnovations InternetConnectivity 3DDisplay HumanInterface LEDBacklight TVProductsInnovations LEDbacklightisveryhot LEDType WhiteLight CurrentCapabilityStandardLED drivecurrent 50mAHighcurrentLED drivecurrent50 150mAHighpowerLED drivecurrent150 1000mA ColorWhiteLEDsRed GreenandBlueLEDs Combinedwhite ForwardvoltagedependsoncolorRed 2V Green 3 5V Blue White 3 5 4V BenefitsofLEDBacklight Powersaving 30 40 savingfor12 14 NB Longerlifetime 50 000hrsvs 20 000hrsofCCFL 0 100 widedimmingrange upto20KHzPWMdimming audionoisefree LowvoltagedriverreducescomplexitypowerdesignEnvironmentalfriendly CCFLcontainsHg LocaldimmingforpowersavingandhigherCR Largesizedirecttypebacklightonly Widecolorgamut NTSC CCFL 78 WLED 80 RGBLED 110 Lightweightandthinprofile PowerSavingofLEDBLU LowdrivevoltagetoensuresafetyoperationTherelationshipbetweenLEDintensityanddrivecurrentislinerLowercurrentisoperatedtoperformthesamebrightnesslevelthatCCFLmodulePowersavingof30 50 ofCCFLpowerconsumption LocalDimmingofTVLEDBLU NTSCcoverCCFL 78 WLED 80 RGBLED 110 WideColorGamut NBPC LCDMNT LCDTV PowerSaving Lightweight ThinprofileSmallcostpremium None PowerSaving DynamicBLUcontrol Cost Reliability HugeLEDAmountThermalcompensation PowerSavingThinprofile Cost Input outputinterface Advantage Challenge LEDBLUMarketPotential Application High Low LEDBLUMarketShare SamsungMPLEDTVat2009 Q2 KickoffLEDTVmarketLowcostEdgetypebecomemainstream HelptorisetheshareratefromCCFLPowersavingfeatures EasytomeetEPA5 0Willbreak50 share 2012 Source DisplaySearch LEDDrivingTopology NB 15 panelforexample6strings 10LEDperstring 20mAVout 33V Pout 4W OB3360FeaturesBuild in60VMOSFET8stringoutputWith60mAcurrentcapabilityperstring160K 320K 620K 1 2MHzfrequency0 100 widerangedimming3 channeltochannelcurrentmatching LEDDrivingTopology MNT 24 panelforexample 1 12strings 15LEDperstring 20mAVout 50V Pout 12W OB3362Features12stringoutputWith60mAcurrentcapabilityperstring150 500kHzfrequency0 100 widerangedimming3 channeltochannelcurrentmatching 24 panelforexample 2 12strings 15LEDperstring 20mAVout 33V Pout 4W parallelconnectiontosupportlargercurrentapplication LEDDrivingTopology LowEndDisplay OB337X0 2VreferencebenefitsefficiencyInternalburstandexternalPWMdimmingOutputovervoltageprotectionOB3372 Boost DIP8 builtin60VMOSFETOB3370N Boost SOP8 ControllerOB3370P Buck SOP8 Controller 26 panelforexample 2 Singlestring 400mAVout 40V Pout 16W LEDvs CCFLCostComparison Q3 2010 USD premium28 premium41 premium61 premium43 LEDTVMarketShareGrowth Source DisplaySearch LEDBacklightforLargeSizeTVPanel DirecttypewithLocaldimming DirecttypewithoutLocaldimming Edgetypebacklight HighPerformance SlimProfile RGBLED WhiteLED WhiteLED RGB Localdimminghaspowersavingandhigh CRfeature High enduseEdgetypesolutionhaslowcostfeature Mainstream DirectBacklight BetteremissionAllowingindependentlydimmingblockbyblock EdgeBacklight AllowingslimdesignFewerLEDnumberandlowercost LEDTVCostDownTrend Directtype Edgetype Advancededgetype Advancededgetype 40inchLEDTV LEDTVDrivingTopology OB3376Dualchannelboostcontroller150 300kHzswitchingfrequencyMultichipsync Costeffective 42 panelforexample4strings150mAperstringVout 150V Pout 90W LEDTVPowerOptimize CurrentSolution OptimizedSolution ReduceDC DCBooster Cost Efficiencyimprovement Headroomvoltagefeedbackforefficiencyandthermalimprovement On BrightLED