Loss modeling for enhancement mode gallium nitride field efect transistor in power converter applications

Wide bandgap devices have been drawn significant research interests for future renewable energy applications thanks to the advantages of high switching performance, high achievable junction temperature, and low on-resistance in comparison with silicon-based devices. It becomes more and more important to understand the switching characteristics for designing high-efficient power converters. A model for estimating switching power losses in enhancement mode gallium nitride (eGaN) Field effect transistor (FET) is developed and presented in this paper. The loss modeling considers both the on resistance and parasitic capacitances that arise from inherent manufacturing processes. A 12V/24V boost converter is prototyped by using eGaN FET and used to validate the proposed model by comparing the experimental result with simulation. The switching losses are calculated for different frequencies and compared with experimental result and show a strong correlation with the expectation in simulations. It shows that the loss model inaccuracy is less than 10%.