Smart Self-driving Gate Driver for Fast Switching and Crosstalk Suppression of SiC MOSFETs

Wide band gap device, like SiC and GaN, have high switching speed potential. However, the actual speed in practical application is limited by the gate loop parasitic and the interaction between high side switch and low side switch in a single phase-leg configuration, known as crosstalk. This paper proposes an isolated voltage source gate driver with crosstalk suppression capability to take full advantage of the inherent high switching speed ability of WBG device. By applying variable gate voltage through the auxiliary circuit, the crosstalk problem can be mitigated. Using the original Vgs voltage as auxiliary circuit driving signal, the gate driver dose not introduce any control signal which avoids the additional signal/power isolation and makes the auxiliary circuit very easy to be implemented on the existing commercial gate driver. LTSPICE simulation and experiment results based on 1.2kV Wolfspeed SiC MOSFET are shown in this paper to verify the proposed gate driver.