Hard-Switching Loss Calculation Model For Fast-Switching GaN HEMT in Half-Bridge Circuit

In power conversion applications using GaN HEMT with high switching frequency, switching loss dominates in total power loss and could be very sensitive to parasitic parameters as a result of fast-switching operation. Since conventional switching loss calculation formula suffers from inconsistent error in designs with GaN HEMTs and various conditions, it is desirable to have effective ways for more accurate estimation on switching loss of GaN HEMT. In this paper, two different kinds of switching loss calculation model are developed in forms of both empirical formula and analytical model, taking into account the effect of critical parasitic inductances and junction temperature. The comparison results of two calculation methods with traditional calculation method are presented for the effectiveness of models. Moreover, the effect of nonideal parameters, such as power loop parasitic inductance, common-source inductance and junction temperature are evaluated.