Magnetic Integration for GaN-based DC-DC Converters

Abstract

With the emerging technology of wide-band-gap power semiconductors and modern ferrite materials, the switching frequency of DC-DC converters based on gallium nitride devices (GaN) can be further pushed to megahertz range. The number of magnetic core is bottleneck of achieving both low cost and high power density. In this paper, a novel magnetic structure with a four-leg magnetic core is proposed to tackle the issue. The DC-DC converters including two inductances can be integrated into the proposed magnetic structure. Two windings of inductances are arranged as orthogonality in the magnetic structure, achieving magnetic decoupling. The inductances based on the magnetic structure are calculated and verified through magnetic circuit analysis and three-dimensional finite element analysis simulation. A GaN-based hardware prototype employing the proposed magnetic structure is built and tested to verify the performance.