Current Source Gate Driver for SiC Multichip Power Modules

The demand in energy efficient electric truck (e-truck) has been increasing, leading to growing demand on more efficient traction inverter. Consequently, the Silicon Carbide (SiC)-MOSFETs with gate driver for fast-switching capability become widely adopted. The conventional Voltage Source Gate Drivers (VSGDs) have problems in significant switching losses, voltage overshoot, and limited control of switching transients if it’s applied in a high switchhing frequency and high power environment.

This project proposes the solution through modelling, optimization, and validation of a Current Source Gate Driver (CSGD) intended for high-power SiC MOSFET modules. The proposed CSGD uses a four-switch H-bridge topology and a resonant inductor to generate a nearly constant, discontinuous gate current during both turn-on and turn-off transitions. The design process combines analytical modelling, LTspice simulation, prototype implementation and double-pulsetest (DPT) validation.

Preliminary study was performed to evaluate the influence of the resonant inductance and operating conditions on switching
performance. For comparison, a commercial VSGD used as the benchmark with matched peak gate current conditions.
Simulation results shows that the CSGD significantly reduces switching duration and energy losses compared with the VSGD by approximately 55–58%, depends on the resonant inductor applied. Furthermore, the experimental validation demonstrate the ability of the proposed CSGD to lower the switching energy losses, provide smoother gate voltage 𝑉𝑔𝑠 transitions and discontinuous gate current operation. The overall results indicate that the proposed CSGD is able to improve efficiency, switching performance, and
device robustness, suitable for future high-power SiC-MOSFET traction inverter applications.