High-Frequency Switching of SiC High-Voltage LJFET

In this paper, inductive-load switching of a high-voltage lateral JFET (HV-LJFET) on 4H-SiC is investigated with a monolithically integrated driver and with an external driver for high-frequency, high-temperature applications. A new ldquocapacitor-coupledrdquo gate driver circuitry is proposed and optimized to utilize a standard MOS driver and enable fast switching speed without the need for a negative power supply. Switching times and losses of the silicon carbide (SiC) HV-LJFET are characterized under various driver conditions and device temperatures. The results reveal that the temperature-independent, high switching speed of the SiC LJFET makes it possible to hard-switch at 3 MHz, 200 V, 1.2 A, and 250degC with good efficiency, significantly higher than silicon devices with similar voltage ratings.