色温可调的高功率LED恒流驱动电路设计

摘要

This paper introduces a new conception of high power LED drive circuit which could be integrated.This LED drive circuit is based on a Buck topology. With the PWM control,it realizes a constant-current drive with two LED output chains in parallel.This paper also studies with the drive problem of power MOSFET in Buck with a wide dimming range of duty cycle.The whole circuit is simulated by the LTSPICE and realized into a demonstrating board. In the measurement of the real circuit, it has an output voltage of 24 V, and an output current from 0 to 700 mA. The laboratory test shows that the performance of the real circuit is corresponding to the theory analysis and the converting efficiency of this circuit achieved to 89.7％.%基于高功率发光二极管(LED)恒流驱动电源的集成化设计,采用无输入滤波电容的Buck变换器与两路并联LED可调恒流驱动电路,实现了高功率LED照明的亮度与色温可调.这里研究了在宽占空比变化范围下的功率M0SFET开关管浮地驱动技术,并用LTSPICE进行了仿真,依据仿真元件的参数搭建了实验电路,得到了输出电压24 V、输出电流0～700mA可调的高功率LED驱动电源实验结果,此结果与仿真数据波形及理论分析一致,电源变换效率达到了89.7%.