Patent ID: 8853736

Claim:
A semiconductor device comprising: a switching power device; and a flywheel diode connected to said switching power device in series, said flywheel diode including a region having a Schottky junction to operate as a Schottky diode and a region having a pn junction to operate as a pn diode, wherein said flywheel diode comprises a gate controlled diode which includes an insulated gate and which is configured to switch alternately between the region having the Schottky junction to operate as a Schottky diode and the region having the pn junction to operate as a pn switch, and wherein said insulated gate of said flywheel diode is configured to receive a control signal (V GA ) which is synchronized with a gate signal (V GE ) supplied to said switching power device, and said flywheel diode is configured to be controlled by said insulated gate receiving said control signal (V GA ) such that before said switching power device is switched over from off to on by said gate signal (V GE ), a first operation mode in which a current flows primarily through at least said pn diode forwardly is changed to a second operation mode in which the current flows mainly through the Schottky diode to reduce backward recovery current in said semiconductor device when the switching power device is turned on.