一种采用PLM调制方法的LED驱动电路

A LED Driver Circuit with Pulse Level Modulation

设计了一种高精度,高效率LED驱动电路,芯片输入电压6 V～40 V,可调恒定电流从350 mA到1 A以上。采用脉冲电平调制以及低边采样结构,与传统的峰值电流控制相比,脉冲电平调制法真正实现了对LED平均电流的控制,效率更高,电流更加精确。设计基于CSMC 0.5 m BCD工艺,并进行了一系列仿真验证。仿真结果表明,当输入电压不同或驱动LED个数不同时,输出电流精度能够被控制在±0.5%和±1%以内。芯片的整体转换效率最高可以达到96.9%,最多可驱动10个LED。

A high precision and efficiency LED driver circuit is designed with its input voltage from 6 V to 40 V,adjustable Constant current from 350mA to more than 1A.Pulse Level Modulation method and low-side sampling structure are used.Compared with the conventional peak current control,the PLM method can really achieve to control the LED ＇ s average current,more efficient and more accurate.The design is based on CSMC 0.5 m BCD process and series of simulations will be giving.The results show that when different input voltages or different number of LED lamps are given,the output current accuracy can be controlled within ±0.5% and ±1%.The highest conversion efficiency of this chip can be achieved at 96.9%,and the driver circuit can drive 10 LED lamps at most.