Design of single switch DC-DC converter with parasitic parameters

This paper proposes an isolated single switch dc-dc converter suited to a high frequency switching operation. The impedance seen at the drain to source node of the switch is mainly designed for achieving zero voltage switching (ZVS) operation and reducing the voltage stress across the switch device. In the proposed converter, leakage inductances of the transformer are integrated to the resonant network. By the proposed design procedure, the transformer is designed to have a proper coupling coefficient in order to satisfy the design requirement solely by the leakage and magnetizing inductances without extra inductors. Thus, it is possible to miniaturize the converter size and achieve high power density. In addition, the junction capacitance of the switch device is used for establishing the resonant network, so it is possible to mitigate the non-linear effect of the junction capacitance of the switch device. As a design example, a 10MHz-18W GaN-based prototype is presented, and the performance of the proposed converter is verified.