A Clamping Circuit Design for Reflected Voltage of Dual Switch Flyback Converter

With high voltage wide input of the converter system, the design of the converter should consider not only the higher voltage level but also the startup issue under low voltage. This paper presents a dual switch flyback converter with improved efficiency and wide-range voltage input. A cascaded dual switch flyback circuit is adopted to reduce the voltage stress requirement and adapt to higher voltage input. For the low voltage start-up state, the transient voltage clamping ability of transient voltage suppressor (TVS) is utilized. By allocating the operating states of TVS under different input voltage values, the requirements of high voltage wide input and low voltage startup are achieved. To verify the performance of the proposed converter, operating principles, steady-state analyses and simulation and experimental results are presented.