An analysis of false turn-on mechanism on power devices

摘要

Currently, driving power circuits at high switching frequency is performed in order to downsize and lighten switching power supplies. Along with it, wide band gap semiconductor devices, GaN and SiC, have attracted attention. However, there is a great constrain related to the false turn-on phenomenon produced by gate noise because these wide band gap semiconductor devices have low threshold voltage. If the false turn-on phenomenon occurs, the efficiency of the power supply decreases. Therefore, this paper analyzes the gate noise performance using simulation and experimental tests focusing on the parasitic inductance of the power devices terminals. As a result, it was found that the gate noises can be related to the recovery current of the body diodes. Additionally, this analysis was theorized by the comparison between the experimental results and the theoretical equation using an equivalent circuit.