谐振式单开关多路输出Boost LED驱动电源

Resonant single-switch multi-string boost LED driver converter

提出了一种谐振式单开关多路输出Boost LED驱动电源及其控制电路,分析了其工作原理及特性.该多路输出Boost LED驱动电源只需要使用1个开关管,1个谐振电感和2n-1个谐振电容就能实现2n路输出的恒流控制,具有变换器电路结构与控制简单、体积小、效率高以及成本低的特点.利用谐振电容的充放电平衡原理,仅需控制其中任意一条输出支路电流,即可实现2n路输出支路的恒流及均流控制;此外,该多路恒流输出LED驱动电源具有固有的短路保护特性,任何一条输出支路短路不会影响其它输出支路的稳态电流.最后,搭建了一台48 W的四路恒流输出实验样机,验证了理论分析的正确性.

A novel resonant single-switch multi-string boost LED driver converter was proposed, the operation principle and characteristics of which were analyzed. It can achieve current balancing among 2n LED strings by using only one active switch, one resonant inductor and 2n - 1 resonant capacitors. Thus it boasts the benefits of simple circuit structure and control, small volume, high efficiency and low cost. By controlling only one output current, the other output currents of this LED driver can be controlled utilizing the charge balance principle of resonant capacitors. If one output branch of the LED driver is short-circuit in the steady state, it will not affect current sharing among the other output currents. Therefore, it has a characteristic of natural short-circuit protection. Finally, the theoretical analysis is verified by a 48 W four-string prototype.