Abstract:
Bridge-arm crosstalk (BAC) refers to the phenomena that the driving state of the switching device kept in the off state is disturbed by the turn-on or turn-off of another switching device in the same bridge-arm branch. Compared with traditional silicon devices, silicon carbide (SiC) metal-oxide-semiconductor field effect transistors (MOSFETs) have higher switching speed and smaller turn-off range, so the BAC of SiC MOSFETs is more serious. To improve the reliability of SiC MOSFETs, it is necessary to analyze the occurrence process and characteristics of the BAC of SiC MOSFETs, and propose corresponding solutions. To this end, a BAC circuit model of SiC MOSFETs is established, and the transient process of the circuit model is analyzed. Based on the analysis results, simplified models of the extreme values of the crosstalk voltage are established, and a safe operation area model based on the BAC of SiC MOSFETs is proposed. Then, a gate driver with bridge-arm crosstalk suppression function is proposed and designed. Finally, the experiments validate the feasibility of the BAC model and the effectiveness of the gate driver.