A Multi-level Self-Driving Gate Driver of SiC MOSFET for Crosstalk Suppression Considering Common-Source Inductance

Compared with conventional silicon (Si)-based devices, silicon carbide (SiC) MOSFET exhibits superior characteristics. However, the high dv/dt caused by high switching speed makes it more susceptible to crosstalk spikes caused by Miller capacitance and common-source inductance, increasing the risk of false-triggering of power device. The mathematical models of most existing methods only consider the Miller capacitance, and adopt the negative turn-off voltage method, which increases the negative gate-source voltage stress of the device and shortens service life. This paper proposes a mathematical model of crosstalk voltage that takes into account both Miller capacitance and common-source inductance, and a multi-level self-driving gate driver is introduced to mitigate positive and negative crosstalk voltages. This approach employs resistor-capacitor-diode and resistor-MOSFET configurations to establish the multi-level negative turn-off voltage and low-impedance branch to suppress positive and negative crosstalk voltages. Incorporating an extra resistor forms a self-driving path for multi-level turn-off voltage, mitigating the negative gate-source voltage stress. The circuit comprises several passive components that can be integrated into the driver IC, eliminating the need for additional negative voltage sources and control signals. The effectiveness of the proposed method is demonstrated through a double-pulse test based on SCT3022AL