Switching Loss Model for Fast-Switching GaN HEMT in Half-Bridge Circuit Considering Parasitic Inductance and Temperature Effect

In power conversion applications utilizing GaN HEMTs at elevated switching frequencies, the predominant source of power loss is attributed to switching, which becomes particularly sensitive to parasitic parameters due to the rapid switching operation. Traditional methods of calculating switching loss have exhibited inconsistencies when applied to designs incorporating GaN HEMTs and various operational conditions. Consequently, there is a pressing need for more precise methods to estimate switching loss in GaN HEMTs. This paper introduces two distinct switching loss calculation models, presented both as empirical formulas and analytical models. These models take into account the influence of critical parasitic inductances and junction temperature. The comparative analysis of these two calculation methods with the experimental results is provided to demonstrate their efficacy. Furthermore, the impact of nonideal factors, such as power loop parasitic inductance, common-source inductance, and junction temperature, is assessed.