安森美NCP112925W离线电源解决方案

OnSemi公司的NCP1129是集成了低导通电阻650VMOSFET的固定频率65kHz或100kHz的峰值电流模式控制器,外接电阻可调整限流值,提升轻载和待机能效的频率反走及跳周期模式，符合美国“能源之星”EPS2.0,待机功耗小于100mW,非常适用于家用电器、DVD播放机及机顶盒的电源系统设计.本文介绍了NCP112x主要特性,NCP1129功能框图和应用电路,25W离线电源评估板NCP1129DIPGEVB主要特性,电路图和材料清单.TheNCP112xproductsintegratesafixed−frequencypeakcurrentmodecontrollerwithalowon−resistance,650VMOSFET.AvailableinaPDIP−7package,theNCP112xoffersahighlevelofintegration,includingsoft−start,frequency−jittering,short−circuitprotection,thermalshutdownprotection,frequencyfoldbackmodeandskip−cycletoreducepowerconsumptioninlightloadcondition,peakcurrentmodecontrolwithadjustableinternalrampcompensationandadjustablepeakcurrentsetpoint.Duringnominalloadoperation,thepartswitchesatoneoftheavailablefrequencies(65or100kHz).Whentheoutputpowerdemanddiminishes,theICautomaticallyentersfrequencyfoldbackmodeandprovidesexcellentefficiencyatlightloads.Whenthepowerdemandreducesfurther,itentersintoaskipmodetoreducethestandbyconsumptiondowntonoloadcondition.Protectionfeaturesinclude:atimertodetectanoverloadorashort−circuiteventwithauto−recoveryorlatchprotection,andabuilt−inVCCovervoltageprotection.Theswitcheralsoprovidesajittered65kHzor100kHzswitchingfrequencytoimprovetheEMI.NCP112x主要特性:•Built−in650V,1AMOSFETwithRDS(on)of8.6_forNCP1124•Built−in650V,1.8AMOSFETwithRDS(on)of5.4_forNCP1126•Built−in650V,5.5AMOSFETwithRDS(on)of2.1_forNCP1129•Fixed−Frequency65or100kHzCurrentModeControlwithAdjustableInternalRampCompensation•AdjustableCurrentLimitwithExternalResistor•FrequencyFoldbackDownto26kHzandSkip−CycleforLightLoadEfficiency•FrequencyJitteringforEMIImprovement•Lessthan100mWStandbyPower@HighLine•EPS2.0Compliant•7−PinPackageProvidesCreepageDistance•ThesearePb−FreeDevices图1.NCP1129功能框图图2.NCP1129典型应用电路图25W离线电源评估板NCP1129DIPGEVBNCP1129DIPGEVB:25WOfflinePowerSupplyHighVoltageSwitcherEvaluationBoardTheNCP1129switcherofferseverythingneededtobuildreliableandcompactAC-DCswitchingpowersupplieswithminimalsurroundingelements.Incorporatinganavalancherated650VMOSFET,convertersbuiltwiththeNCP112Xcanbesafelydesignedforinternationalconditionswithoutjeopardizingtheoverallreliability.TheNCP112XimplementspeakcurrentmodecontrolwithadjustablerampcompensationthatensuresstabilityinContinuousConductionMode(CCM)operation.Withanexternalresistor,themaximumpeakcurrentisadjustable,allowingthedesignertheabilitytoinjectrampcompensationtostabilizeCCMpowersupplies.Ashortcircuitfaultconditionisindependentlydetectedfromtheauxiliarywindingvoltageresultinginimprovedshortcircuitprotectionwithtrueoverloaddetection.TheSourcepinprovidesaccesstotheMOSFETsource,allowingforoverpowercompensation.Withasupplyrangeupto26V,theswitcheralsoprovidesajittered65kHzor100kHzswitchingfrequencyoperatedinpeakcurrentmodecontrol.Whenthepoweronthesecondarysidestartstodecrease,theswitcherautomaticallyfoldsbackitsswitchingfrequencydowntoaminimumlevelof26kHz.Asthepowerfurthergoesdown,thepartentersskipcyclewhilelimitingthepeakcurrent.NCP1129DIPGEVB主要特性:UniversalACinputrange(85–265Vac).InputfilterforconductedEMIattenuation.Verylowstandby(noload)powerconsumption.Frequencyfoldbackunderlightloadand/orovercurrentconditions.Pi-networkoutputripplefilter.Inherentover-current,over-voltageandovertemperatureprotection.图3.25W离线电源评估板NCP1129DIPGEVB外形图深圳市傲壹电子有限公司材料清单: