Advanced Electric Power Conversion Laboratory

Name: Minfan Fu


School of Info. Science and Tech.

ShanghaiTech University

Room 202C, SIST Building 2

393 Middle Huaxia Road

Pudong, Shanghai 201210

Tel: +86-021-20684455

A journal paper is accepted by IEEE Trans. Power Electron.

M. Fu, C. Fei, Y. Yang, Q. Li*, and Fred C. Lee, “Optimal Design of Planar Magnetic Components for A Two-Stage GaN-Based DC/DC Converter", IEEE Transactions on Power Electronics.


This paper develops a 200 Wwide-input-range (64V-160V to 24V) rail grade dc/dc converter based ongallium-nitride devices. A two-stage configuration is proposed. The firstregulated stage is a two-phase interleaved buck converter (>400 kHz) and thesecond unregulated stage is a LLC (2 MHz) dc transformer. In order to achievehigh frequency and high efficiency, the critical-mode operation is applied forthe buck converter, and the negative coupled inductors are used to reduce thefrequency and the conduction losses. Then a systematical methodology isproposed to optimize the planar coupled inductors. For the unregulated LLCconverter, it can always work at its most efficient point and an analyticalmodel is used to optimize the planar transformer. Finally, the proposed dc/dcconverter, built in a quarter brick form factor, is demonstrated with 95.8%peak efficiency and 195 W/in 3 power density.