A 10-MHz isolated Class DE resonant DC/DC converter based on GaN HEMT

The power density of DC/DC converter could be extremely increased when the switching frequency increases to the very high frequency (VHF, 30-300MHz generally). In addition, the soft-switching characteristic of power switches could contribute to the improvement of converter's efficiency. Therefore, VHF power converters with soft-switching characteristic have the merits of high power density and high efficiency, which keep in with the developmental tendency of advanced power electronic applications. In this paper, a 10-MHz 5W isolated resonant DC/DC converter based on GaN HEMT is designed and validated. The power stage of this 20V_in/5V_out converter consists of a Class DE inverter, a Class E rectifier and an air-core transformer. The output voltage of DC/DC converter is regulated by ON/OFF control. The zero-voltage switching (ZVS) operating principle and design procedures are amply introduced. The results obtained from simulation and experiment prototypes illustrate that ZVS characteristic of GaN HEMT can be achieved. In addition, air-core transformer and ON/OFF control are feasible functionally.