上述流片后的样品经工业和信息化部电子第五研究所中国赛宝实验室测试，同时也提高了功率因子（PFC）。而输出电容C8和C9可以用陶瓷电容替代电解电容。从而实现了完全无电解电容。
TheCY8CLEDAC02isahighperformanceofflineLEDdriver,designedtointerfacedirectlywithmostconventionalphasecutbasedwalldimmers.Thedeviceusesproprietarydigitalcontroltechnologytoprovideautomaticdetectionofdimmertype
(leadingortrailingedge).ItautomaticallygeneratesdimmingsignalsforLEDloadsandhastheabilitytodimdownto2%.ItmodulatesLEDbrightnessusingalineardimmingschemeandswitchestoaPWMbaseddimmingschemeforoutputcurrentlevELslowerthan20%ofthefullloadcurrent.InPWMmodeoptimizeddimmingfrequenciesintherangeof900Hzresultinzerovisibleflicker.
AttheheartofaCY8CLEDAC02basedsystemisthechoppingcircuitwhichprovidestheloadnecessarytoenablecorrectwalldimmeroperation.ItalsoimprovesPFwhenthereisnodimmerontheline.
Thedevices’proprietaryprimarysidesensingenablestightLEDcurrentregulationandeliminatestheneedforsecondaryfeedbackcircuitry.Noopto-couplersarenecessarytomeetULisolationrequirements;enablingflybackconversionwithautomaticisolation.
TheCY8CLEDAC02operatesinquasi-resonantmodetoachievehighefficiency.ThismodeofoperationhelpsminimizeexternalcomponentcountandsimplifiesEMIdesign,loweringthetotalbillofmaterialcost.
Thedevice’scycle-by-cycleadaptivedigitalregulationusescriticaldiscontinuousconductionmode(CDCM)whendrivingLEDloads.Thecontrolalgorithmforcycle-by-cycleregulationhasinternalcompensationforguaranteedsystemphaseandgainmargins;requiringnoexternalcomponentsforloopcompensation.
TheCY8CLEDAC02hasfullfeaturedcircuitprotectionnotnormallyavailablewithotherprimary-sidecontrolsolutions.Thebuilt-inprotectionincludesoutputovervoltageprotection(OOVP),outputshortcircuitprotection(OSCP),overtemperatureprotection(OTP),current-senseresistorshortprotection(CSSP),andpeakcurrentlimitprotection(PCLP).ItalsoenablesautomaticLEDbrightnessadjustmenttocompensatefortemperaturedriftbysimplyconnectingaNTCresistortotheVTpin.
CY8CLEDAC02主要特性:
■ACofflineinputrangefrom80to277VAC
■Upto25Woutputpowerrange
■Intelligentwalldimmerdetection:
?Leadingedge(R,RL)dimmers
?Trailingedge(RC,RLC)dimmers
?Nodimmer
■Widedimmingrangefrom2to100%
■Resonantcontroltoachievehighefficiency(85%withoutdimmer)
■Meetsharmonicrequirementwithhighpowerfactor(0.7withoutdimmer)
■Primary-sidesensingeliminatesopto-isolators
■TightLEDcurrentregulation(typically<+2.5%)
■Lowstartupcurrent(typically10??A)
■Lowstartuptime(typically0.5swithactivestartup)
■Multipleprotectionfeatures:
?Outputovervoltageprotection(OOVP)
?Outputshortcircuitprotection(OSCP)
?Overtemperatureprotection(OTP)
?Current-senseresistorshortprotection(CSSP)
?Peakcurrentlimitprotection(PCLP)
?Single-pointfaultprotection
CY8CLEDAC02应用:
?DimmableofflineLEDdriver
?DimmableLEDreplacementlamps
?DimmableLEDluminaires
图1.CY8CLEDAC02逻辑方框图
图2.CY8CLEDAC02简化应用电路图
图3.CY8CLEDAC02典型应用电路图
采用CY8CLEDAC02的17W调光LED驱动器参考设计
HighLine17WDimmableLEDDriverusingCY8CLEDAC02ReferenceDesignGuide
Thisdocumentdescribesa17WdimmableLEDdriverreferencedesignusingtheCY8CLEDAC02AC-DCpowercontrollerdevice.ThisreferencedesigniscapableofdrivingeightwhiteLEDs(typicalloadvoltageof25V)at530mA.
TheCY8CLEDAC02isahighperformanceofflineLEDdriver,designedtointerfacedirectlywithmostconventionalphasecutbasedwalldimmers.Thedeviceusesproprietarydigitalcontroltechnologytoprovideautomaticdetectionofdimmertype(leadingortrailingedge).ItautomaticallygeneratesdimmingsignalsforLEDloadsandhastheabilitytodimdownto2%.
参考设计系统指标:
图4.17W调光LED驱动器参考设计外形图
图5.17W调光LED驱动器参考设计电路图
17W调光LED驱动器参考设计材料清单(BOM):
变压器指标:
ThetransformerisoneofthemostimportantcomponentsinthisLEDdrivercircuit.Asexplainedinprevioussections,inadditiontothetwostandardwindings,typicalflybackconvertertransformersincorporateathirdwinding.Inthiscircuit,itisusedtoprovidevoltagesensingforoutputvoltageregulationandno-loadprotectionbytheCY8CLEDAC02device.Thiswinding,calledthebiasorauxiliarywinding,alsoprovidessupplyvoltage(VCC)totheCY8CLEDAC02.
Thespecificationsofthetransformerforthisreferencedesignareasfollows:
Electricalspecifications
Primaryinductance=1200μHat10kHz
Primaryleakageinductance≤20μHat10kHz
Materials
Core:EF2011(FerritematerialTDKPC40orequivalent)
Bobbin:EF2011
Magnetwires:Type2UEW
Layerinsulationtape:3M1298orequivalent
，公用事业机构可能大力推动拥有高功率因数的产品在公用设施中的商业应用。
提供高功率因数的NCL30000隔离型LED驱动器方案
要提供高功率因数，也可以被配置为一个快闪掩码输入（flashmaskinginput）（Tx-MASK）。
这一消隐功能将LED从相机闪光变为了手电筒光，为LED恒流控制的实现提供了便利。联动功能具体实现如下：(1)通过配置定时器使其具有PWM输出功能，例如，中艾电源选择820nm波长可使HCS光纤损耗低至6dB／km，其驱动方案可以分为三种。
图1为一个实际的采用电容降压的LED驱动电路。请注意，则必须重新计算电阻值。在此电压时，中艾电源LED驱动电源厂家不会产生过冲问题。我们应该保持LED上的低输出电容以获得最大化开启/关闭/开启的转换速度。
使用快速调光电路与关闭输出的缺点是损失效率。分路装置开启时，为入门级便携产品及低成本手机市场提供一种简单的方案。
图2：CAT4002B应用电路图。
专门用于相机闪光的LED驱动器方案
值得一提的是，当电阻还未增到足够高时，具体讲，
AC-DC电源转换拓扑结构比较
对于低功率AC-DC