Silicon carbide (SiC) MOSFETs are gaining increasing usage in industrial applications demanding for higher power density and lower power dissipation. Despite the high switching rate nature of this device, some problems, including intensified oscillations, overshoots, electromagnetic interference (EMI) and possible additional losses, do arise. In this paper, a new active gate driver (AGD) with Auxiliary Gate Current Control (AGCC) unit is proposed. To optimize the switching transients, the gate current is regulated throughout the whole switching process by adjustment of the AGCC reference voltage. Advantageously, this regulation is effective both for normal operation and short-circuit fault conditions. Extensive empirical results on a 1.2kV, 300A SiC MOSFET confirmed performance improvement achieved by the proposed AGD, especially on the suppression of induced overshoots and oscillations.
 

SiC-MOSFET,Active Gate Driver,CPLD,Overshoots,Oscillations