一种减少输出纹波的单级反激LED驱动电路

A Novel Lower Output Ripple Single-stage Flyback LED Driver

鉴于成本低、效率高等优势,AC-DC单级LED驱动电路可使用单级电路实现输入功率因数校正和输出DC-DC恒流控制,但通常存在较大的输出2倍工频纹波的问题,而电流纹波是影响LED光学特性和寿命的重要指标。首先,提出了一种基于辅助绕组的单级反激LED驱动电路;然后,采用电流纹波抑制策略分析了所提电路的工作原理和实现低输出电流纹波的条件;最后,通过仿真和实验验证了理论分析的正确性和有效性。实验结果表明,所提的LED单级驱动电路能够在不影响输入特性的基础上有效地降低了输出电流纹波。

AC-DC single-stage LED driver realizes power factor correction and DC-DC constant current control due to low cost and high efficiency advantages. It usually exists the problem of larger twice line frequency output ripple, and the current ripple is one of the important indicators to affect LED light-emitting properties and lifetime. First, a suitable kind of LED driver that single-stage flyback PFC circuit based on auxiliary winding and current ripple suppression strategies is put forward in this paper. Then, the working principle of the proposed circuit and the implementation condition of low output current ripple are analyzed. Finally, simulation and experiment are carried out to verify the correctness and feasibility of the theoretical analysis. The results show that the output current ripple can be reduced effectively through the proposed single-stage LED driver, and the input characteristics cannot be affected.