Comparative Study on Driving Switching Characteristics of GaN-FET and SiC-MOSFET in Transient High Voltage Pulse Discharge Circuit

As a new type of wide band gap semiconductor device, GaN-FET has faster switching speed and higher power density than SiC-MOSFET. It has a good application prospect in the field of pulse power technology. Aiming at the effect of gate driving circuit (mainly gate on-resistance and off-resistance, gate-source capacitance and driving voltage) on the switching behavior of semiconductor devices, this paper designs a pulse discharge test circuit to build a GaN-FET switching process. The circuit model uses a mathematical model to analyze the typical characteristics of GaN-FET switching behavior. And using SiC-MOSFET with similar parameters in the data sheet for comparative experiments, revealing the difference in switching characteristics of the two semiconductor devices in the transient pulse loop based on driving regulation. It can provide reference for driving design of GaN-FET in high voltage pulse generator. In addition, based on the results of comparative experiments, the driving parameters are designed to build a 4-level Marx generator experimental prototype with GaN-FET and SiC-MOSFET as the main switches. It has been preliminarily verified that GaN-FET can generate faster leading-edge high-voltage nanosecond pulses and have greater stability at high repetition rates.