Performance Benchmarking of Si and GaN MOSFETs in Isolated Buck-Boost DC-DC Converter

The performance of two different power transistor-Silicon MOSFET and Gallium Nitride (GaN) MOSFET are evaluated in this paper. The evaluation between the two transistors has been demonstrated through case study and the multi-mode quasi-Z-source isolated buck-boost converter (qZS-IBBC) is chosen for conducting the study. The qZS-IBBC features different switching conditions in three operation modes which are the buck, boost, and normal mode. The switching and conduction losses of the primary switches of the converter is used as benchmarking parameters for the two MOSFETs. The analysis is done based on the given parameters of the MOSFETs in the datasheet. The GaN MOSFET shows a better performance than its silicon counterpart in case of switching losses with a 24% improvement. The Si MOSFET outperforms the GaN in case of conduction losses with a 32% improvement. A 300 W prototype is tested in three different operation modes to verify the given analysis.