Novel dead time controlled gate driver using the current sensor of SiC-MOSFET

Abstract

In comparison with Si-IGBT, Silicon Carbide (SiC)-MOSFET is expected to reduce switching loss and conduction loss of low-current region, as well as to remove external Free Wheeling Diode (FWD). However, because SiC-MOSFET bodydiode has high forward voltage, the diode conduction loss increases in the period of the dead time and, as a result, its loss reduction effect by using SiC-MOSFET decreases. This work proposes a novel dead time controlled gate driver using the current sense transistor integrated with SiC-MOSFET. Proposed gate driver has a high responsiveness and a high robustness against the switching noise, the dead time can be shortened within 0.1μs without external components. In addition, it can consist with both the dead time control and the detection short-circuit current, which is the radical function in one current sensor. In the experimental validation result of 10kW boost converter with SiC-MOSFET, the efficiency with the proposed gate driver was 1% higher than the efficiency without it.