Challenges on drive circuit design for series-connected SiC power transistors

Abstract

The breakdown voltages of the currently available 1.2 and 1.7-kV classes Silicon Carbide (SiC) transistors are not sufficient to operate under medium blocking voltages. On the other hand, the fabrication yields of the available high-voltage SiC transistors are still low, resulting in low current capabilities. Series-connection of several individual transistors is the solution to meet medium blocking voltages and high current ratings. This paper identifies the most crucial design challenges of gate and base drive circuits suitable for driving fast-switching series-connected SiC transistors. These challenges are presented and analyzed using Finite Element Method simulations and experimental investigations.