一种单开关多路均流输出LED驱动电路的分析与设计

摘要

In view of the complicated structure and control logic of the multichannel LED current-balancing technology,a singleswitch multi-output LED driver based on resonant capacitor is proposed.Compared with conventional passive and active balancing methods,the proposed driver only uses one active switch and one inductor or magnetic component,and can drive odd or even channels' LED load,thus it benefits from small volume,low cost and high performance.Moreover,the control circuit and control logic are simple,because the drive circuit can achieve current balance of each channel by only controlling the current of a branch.In this paper,the principle of the driving circuit is analyzed,and the theoretical results are verified by the PSIM simulation software and the experimental prototype.%针对现有多通道LED均流技术的结构和控制逻辑较复杂的问题,提出一种基于谐振电容的单开关多路输出LED驱动电路.与传统的有源和无源均流方法相比,该驱动电路只使用一个半导体开关管和一个磁性元件,如电感或变压器,而且可以驱动奇数或偶数通道的LED负载,因此该电路具有体积小、成本低、性能高等优点.另外,该驱动电路只需通过控制一条支路的电流便可实现各通道的电流平衡,控制电路和控荆逻辑均较为简单.对该驱动电路的均流原理进行了分析,并通过PSIM仿真软件和实验样机对分析结果进行了验证.