A Quasi-Multilevel Gate Driver for Fast Switching and Crosstalk Suppression of SiC Devices

Abstract

The crosstalk phenomenon in a phase-leg configuration forbids the operation of SiC devices at high switching speed. A multilevel gate driver (MGD) is well-known for crosstalk mitigation, however, it requires two driver ICs and two voltage supplies to generate four different levels in the gate-source waveform. This paper presents a low-cost quasi-multilevel gate driver (QMGD) for crosstalk suppression which can be implemented on a single driver IC using only positive supply voltage. With a simple auxiliary circuit of the parallel-connected transistor, zener diode, and a capacitor, the proposed driver can generate multilevel output. The auxiliary transistor governs the charging and discharging of the capacitor, controlling voltage at the source terminal of SiC MOSFET and thus generating different voltage levels essential for crosstalk suppression. Performance of the proposed gate driver is validated through Spice based simulation as well as experimental tests conducted with Cree C2M0025120D. It is concluded that the proposed QMGD can replace a complicated MGD without any loss of performance.