Study of negative bias on the IGBT's gate

Abstract

A negative gate bias during the IGBT's (insulated gate bipolar transistor's) turn off modifies the switching parameters. This effect is highlighted and analyzed. Unlike the MOS transistor, the IGBT's turn-off behavior at high frequency with negative gate bias shows a strong inversion layer at the oxide-n-semiconductor interface. A simplified model is used to show the improvements in delay time and current and voltage switching speeds brought about by the negative gate bias. The negative bias can reduce the turn-off losses by 25%.<>