turn-on switching loss. Turn-off losses can only be reduced
during the Miller effect and MOS turn-off portion of the turnoff
transient, by reducing the gate resistance. However, this
increases the rate of change of collector voltage, which strongly
affects the IGBT latching current and RBSOA. During the
turn-off period, the turn-off gate resistor Rgoff determines the
maximum rate of collector-voltage change. After the device
turns off, turning on transistor T1 prevents the spurious turnon
of IGBT by preventing the gate voltage from reaching the
threshold voltage.