Influence of Gate Resistance on Crosstalk of SiC MOSFETs

SiC MOSFETs are widely used in high frequency applications due to the material advantages of SiC, which causes SiC MOSFETs suffer more from crosstalk in bridge topology. In the half-bridge modules with alternately conductive devices, the gate resistance of the two arms should keep the same. However, existing researches about crosstalk all consider that the gate resistance of a certain bridge-arm is constant. This paper studies the influence of changing upper and lower bridge gate resistance synchronously on crosstalk. The theoretical analysis of the influence of gate resistance on crosstalk is presented first. Then a double-pulse test platform is built to verify the theoretical analysis. Compared with just regarding the gate resistance of off-state device as univariate, the positive spike of crosstalk voltage is much smaller. Consequently, the upper limit of gate resistance to avoid shoot-through current is larger. This conclusion can provide better guidance for driver design of SiC MOSFETs in half-bridge topology.