Parasitic Capacitances Effect on Transient Current Sharing in Parallel Connection of GaN FETs

The paper deals with the impact of parasitic capacitance on the switching operation of GaN FET devices in parallel connection. A suitable experimental board has been developed to investigate the switching transient current share features for several GaN FETs connected in parallel to perform a single high-current switch. Every device can be driven independently, and a source shunt per each GaN FET monitors the transistor current. Simulation runs and experimental tests show the switching mechanism and parameters involved in the transients’ current share. The paper aims to give insights into the designing boards of paralleled GaN FETs regarding the influence of parasitic capacitances in the transient current peak distribution to find the maximum parasitic capacitance reachable without overcoming the limit of impulsive device current. The study contributes to developing reliable power modules made of several GaN FETs in parallel connection.