LED电平移位器包括故障检测

摘要：虽然许多LED驱动IC工作在相对较低的电压，可以工作在更高的电压，从而驱动串联多个LED，通过增加一个共同的基晶体管的电平转换器，这种IC（MAX6974）所示。

Maxim>AppNotes>DisplayDriversKeywords:LEDdrivers,multiple-LEDdrivers,NPNtransistors,levelshifters,faultdetection,open-circuitdetectionDec22,2010APPLICATIONNOTE4549LEDLevelShifterIncludesFaultDetectionAbstract:AlthoughmanyLED-driverICsoperateatrelativelylowvoltage,youcanoperateathighervoltageandtherebydrivemultipleLEDsinseries,byaddingacommon-base-transistorlevelshiftertothisIC(MAX6974)asshown.AsimilarversionofthisarticleappearedintheOctober18,2007issueofEETimesmagazine.TherelativelylowoperatingvoltageofmanyLED-driverICspreventsthemfromdrivingmultipleLEDsinseries,butyoucancircumventthislimitationbyaddingacommon-base-transistorlevelshifterasshowninFigure1.NPNtransist