AC‐coupled gate driver with gate current switch under single power supply for normally‐off SiC JFET

Theoretically, normally‐off silicon carbide (SiC) junction field‐effect transistors (JFETs) do not require a negative gate voltage supply because they are in an off‐state when the gate–source voltage is 0 V. However, most gate drivers for normally‐off SiC JFETs require not only a positive power supply for turning on the JFET but also a negative power supply for turning it off and maintaining a negative gate–source voltage to suppress a false turn‐on power loss caused by crosstalk during fast switching. Therefore, modifications of gate drivers increase complications and costs. In this study, a normally‐off SiC JFET gate driver, which can be realized using a simple circuit configuration with a single power supply, is proposed. To minimize undesirable crosstalk, the gate‐source voltage of the JFET is driven to a negative value and retained in the state for a long period of time. © 2020 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.