基于TRIAC调光,提出了一种用于LED驱动芯片中,测量经TRIAC调光器斩波后AC线电压导通角的技术,并给出了其具体电路实现方式。此方法具有测量精度可调、负载LED亮度范围可调等诸多优点,能够很好地满足实际应用的需求。基于0.5 μm BCD工艺,用Hspice进行仿真,结果表明: 本文提出的相角测量技术能准确测量AC线电压导通角的大小,从而精确控制流过负载LED的电流。

A technique for phase measurement used in LED driver based on TRIAC dimming was proposed and its implementation method was given. There were many advantages of this method, for example: the adjustable accuracy, the variable LED brightness and so on. the needs of practical application can thus be satisfied. With simulation using Hspice based on 0.5 μm BCD process, it is shown that the angle that has been cut away by TRIAC can be accurately measured, and the current flowing through the LED load can be controlled very well.