Low-Loss Active Gate Driver with Surge Voltage Detection for SiC MOSFET

Abstract:
The conventional gate drive method controls switching characteristics by adjusting a gate resistance. In this method, high-speed switching to reduce switching loss increases surge voltage, which can exceed the breakdown voltage and cause destruction. To address this issue, a new active gate control method is proposed. The proposed method detects and feeds back surge voltage of the SiC MOSFET to control surge voltage. By controlling surge voltage within a range close to the breakdown voltage of the SiC MOSFET, faster switching than conventional methods are possible, reducing switching loss. Experiments with a prototype confirmed that the fastest switching can be achieved while ensuring that the breakdown voltage is never exceeded. Additionally, it was demonstrated that switching loss can be reduced by 36% to 52%