Research on a single-stage Flyback/boost LED driver with lower output ripple

Due to low cost and high efficiency, the AC-DC single-stage LED driver has been used to realize power factor correction and DC-DC constant current output. But there usually exists the problem of larger twice line frequency output ripple, which is one of the important factors to affect LED optical properties and lifetime. A suitable kind of LED driver that a single-stage modified Flyback power factor correction circuit combined with a auxiliary CCM Boost converter and a current ripple suppression strategy is proposed in this paper, the operating principle of the proposed circuit and the implementation condition of low output current ripple are analyzed. The simulation and experiment are carried out to verify the correctness and feasibility of the theoretical analysis. The experimental results show that the output current ripple can be reduced effectively through the proposed single-stage LED driver, and the input characteristics doesn't be affected.