Paralleling SiC-Power-MOSFET Body Diodes under Harsh Switching Conditions

Abstract:
To reduce switching losses of SiC-Power-MOSFETs, one approach is to maximize the switching speed by using dead-time optimization. However, if the driver fails to meet the required dead-time, the body diode may be operated under avalanche conditions due to high switching stress. Since power modules consist of numerous semiconductors operating in parallel, the energy distribution between the separate devices during a possible avalanche event of the body diodes has to be taken into consideration, which will be addressed in this paper. The main focus is the parallel operation of semiconductors with different breakdown voltages under avalanche conditions due to high switching stress as well as the impact of the inductive coupling among the parallel devices during avalanche operation.