单端初级电感变换器拓扑的LED电源设计

Design of LED Power Supply Based on Single-ended Primary Inductance Converter

单端初级电感变换器(SEPIC)拓扑结构的转换器既可以实现升压,也可以实现降压,而且转换效率也很高,可作为LED的驱动电源。讨论了LED对驱动电源的要求和SEPIC拓扑的电流连续导通模式(CCM)、临界连续模式(TM)和断续导通模式(DCM)的工作原理,重点论述了TM下的工作机制,并阐述SEPIC拓扑电路的器件参数选择原则。在此基础上设计了SEPIC电路,结合相关的控制芯片,对电路进行PWM和PFC,实验结果证明了分析的正确性。

The converter of single-ended primary inductance converter（SEPIC）topology structure with high efficiency can achieve boost and buck,so it is used as the driving power for LED.Firstly,the requirements of the power driving LED are discussed,and the working principles of the three models in the SEPIC are introduced,such as CCM,TM and DCM.It focuses on the working mechanism of the TM.Secondly,it expounds the SEPIC topology parameter selection principles of circuit device.On the basis of the principles,through designing a SEPIC circuit and the relevant control chip to accomplish PWM and PFC,the experimental results prove the correctness of the analysis.