Full-bridge quasi-resonant class-DE inverter for optimized high frequency operation with GaN HEMT devices

GaN HEMT devices exhibit improved performance in terms of switching speed and reduced on-state resistance, especially if low-voltage and high-frequency conditions are considered. In this paper, a high-power density quasi-resonant converter is proposed in order to improve both the maximum output power and the maximum operating frequency with GaN HEMT devices. Since the proposed converter operates as a class-E converter, there is no negative current flowing through the switching devices, perfectly matching the GaN HEMT devices restrictions. Besides, the proposed converter reduces the component count by using the parasitic output capacitance for high switching applications. An analytical model of the resonant converter operation is proposed in this paper, with special emphasis in the design equations, and an experimental prototype has been built to prove the feasibility of the proposed converter.