New voltage sensing terminal of the IGBT for the short-circuit protection with suppressed floating effect by employing the internal PMOS

We have proposed a new floating p-well voltage reset scheme for reliable and fast discharging voltage sensing terminal by employing the negative gate bias, which stabilizes the floating p-well voltage spontaneously during the transient state and off-state by turning on the internal PMOS of the floating p-well IGBT. We have investigated the switching stability characteristics of the floating p-well voltage. Experimental results show that the discharging time and voltage spike of the floating p-well voltage is successfully controlled by employing the gate bias polarity and filter capacitor. Simulation results also shows that the hole current diverting effect due to the turn-on of the internal PMOS suppresses the floating p-well voltage during the turn-off transient.