由于世界范围的能源短缺，近年来节能议题日趋受到重视，目前的照明设备为达到低功率消耗、寿命长、无污染、启动时间短等需求，已经大量采用高亮度的半导体固态发光二极管(LED)取代传统的照明光源。LED驱动器则提供恒定电流控制。使得LED 维持稳定的发光亮度与饱和的色彩频谱，为了设计符合工业与节能标准的显示屏系统。LED驱动器必须有自动省电特性。

The worldwide energy shortage has raised public awareness on energy saving issues，and the revolutionary LED light source has therefore been widely adopted for its low power consumption，long life，environmental protection，and fast turn-on time features．As the LED brightness is adjusted by current，a constant current LED driver is necessary to keep unifOrm LED brightness．FurthermOre．an LED driver with power saving functions becomes popular in order to meet the energy efficiency requirements in LED traffic sign and message sign applications．