Patent ID: 7514967

Claim:
An apparatus for driving a voltage driven type switching element including a collector terminal, an emitter terminal and a gate terminal connected to a power source supplied at a voltage level, the apparatus comprising: a discharge circuit connected to the voltage driven type switching element and operable to discharge an electrical charge stored at the gate terminal at a discharge rate during a turn-off operation of the voltage driven type switching element in which the voltage driven type switching element makes a transition from on to off; a discharge rate controller circuit operable to control the discharge rate so that a change rate over time of a voltage between the collector terminal and the emitter terminal is limited to a second change rate during the turn-off operation; and a delay circuit operable to delay a starting time of the operation of the discharge rate controller circuit to limit the discharge rate to the second change rate for a prescribed delay time after a start of the turn-off operation and before a time when the voltage between the collector terminal and the emitter terminal first reaches the voltage level of the power source, thereby providing a time period during which the discharge rate is initially at a first change rate higher than the second change rate.