1-MHz LLC Resonant DC Transformer (DCX) With Regulating Capability

This paper presents an MHz LLC resonant converter with load-regulating capability. Unlike the two-stage solution, most of input power is delivered to the load directly by the main transformer in the proposed topology. Moreover, only small portion of input power is converted by two stages: 1) auxiliary transformer and 2) a cascaded PWM dc-dc converter. Therefore, the sacrifice of the efficiency caused by the two-stage conversion is minimized. The operating principle of the proposed converter is analyzed, and a 1-MHz prototype based on the proposed converter is built-up to verify the high-frequency, high-efficiency, and output-regulating capability.