FairchildFL7794PWM调光大功率LEDAC直接驱动方案时间:2016-06-0612:52:06作者:Fairchild来源:中电网Fairchild公司的FL7794是直接从AC线驱动的LED驱动器,从而最小化外接RC无源元件的数量,输入电压90~305VAC
正常配置下一个电阻可调整LED功率,一个电容提供稳定电压来偏置内部并联稳压器
器件提供模拟/PWM可调光特性,采用高PF和低的THD可获得高效率,主要用于高稳定的大功率LED照明系统
本文介绍了FL77944主要特性,框图,以及12W评估板FEBFL77944A4测试条件,电路图和材料清单
TheFL77944isadirectAClineLEDdriverwithaminimalnumberofexternalRCpassivecomponents
Innormalconfiguration,oneresistoristoadjustLEDpower,andonecapacitoristoprovideastablevoltagetoaninternalbiasingshuntregulator
TheFL77944providesphase-cutdimmingwithwidedimmingrange,smoothdimmingcontrolandgooddimmercompatibility
ItachieveshighefficiencywithhighPFandlowTHD,whichmakestheFL77944suitableforhigh-efficiencyLEDlightingsystems
TheFL77944hasadedicatedDIMpinwhichcanbeusedwithanalogordigitalPWMdimming
TheFL77944canalsobeused