High-Speed Resonant Gate Driver With Controlled Peak Gate Voltage for Silicon Carbide MOSFETs

Abstract

Parasitic inductance in the gate path of a silicon carbide MOSFET places an upper limit upon the switching speeds achievable from these devices, resulting in unnecessarily high switching losses due to the introduction of damping resistance into the gate path. A method to reduce switching losses is proposed, using a resonant gate driver to absorb parasitic inductance in the gate path, enabling the gate resistor to be removed. The gate voltage is maintained at the desired level using a feedback loop. Experimental results for a 1200-V silicon carbide MOSFET gate driver are presented, demonstrating the switching loss of 230 μJ at 800 V and 10 A. This represents a 20% reduction in switching losses in comparison to that of conventional gate drive methods.