基于无源均流的单开关降压式四输出LED驱动器

提出了一种基于无源均流的单开关降压式四路输出LED驱动器,并分析了其工作原理及特性。该驱动器利用多电容电路结构实现了每个LED支路的均流,因此仅需控制其中一条输出支路的电流,即可实现对其他支路的电流控制。此外,所提出的LED驱动器只使用了一个有源开关,进一步减小了电路的体积,简化了驱动控制。与传统多输出LED驱动器相比,该电路可实现非隔离单开关降压转换,使其应用范围更广。最后,搭建了一台100 W四路输出实验样机,验证了所提LED驱动器理论分析的正确性与可行性。

Single-switch Four-string Step-down LED Driver Based on Passive Current Balancing

A single-switch four-string step-down LED driver with passive current balancing is proposed and analyzed. The proposed LED driver can realize the current balancing of each LED branch. Therefore, by controlling one output current, the output current of other LED strings can be controlled via passive current balancing, which makes its control simple. The proposed LED drivers use only one active switch, which decreases the volume of circuit and simplifies the control loop. Compared with the traditional multi-string LED driver, the proposed LED achieves non-isolated step-down conversion, which benefits from small size and low cost. Finally, a prototype of four-string LED driver with 100W output is built to verify the studied results.