A High-Frequency CLCL Converter Based on Leakage Inductance and Variable Width Winding Planar Magnetics

A CLCL resonant DC/DC converter based on the transformer leakage inductance is proposed in this paper. With the adoption of leakage inductance, the system volume and magnetic losses can be greatly reduced. The optimal design method of the proposed converter is analyzed in detail. Also, the advantages of the CLCL converter are depicted compared with LLC circuit. The design of variable width winding planar magnetics is depicted in detail, which can reduce the winding losses and parasitic capacitance. A 1-MHz prototype using gallium nitride FETs is built to verify the feasibility of the proposed resonant converter and design method.