SEMICONDUCTOR DEVICE FOR DRIVING LED, AND LED DRIVING DEVICE

摘要

A semiconductor device for driving LED, which has excellent power conversion efficiency and is suitable for miniaturizing, and a LED driving device using such semiconductor device are provided. The semiconductor device for driving LED is provided for driving one or more LEDs, and is characterized in that it is provided with an input terminal connected on a high voltage side of a rectifier circuit for rectifying an alternating voltage and inputting a voltage from the rectifier circuit; an output terminal for applying current to one or more LEDs, a switching element block, which is connected between the input terminal and the output terminal and has a first switching element; a regulator section for forming a power supply voltage for driving and controlling the switching element block; and a drain current detecting section for detecting a drain current of the switching element block. The semiconductor device is further characterized in that it is provided with a control section for controlling the first switching element to be turned on and off to interrupt the drain current of the switching element block when the drain current reaches a prescribed threshold value.