Patent ID: 8724357

Claim:
A power semiconductor device comprising: a high side switching element and a low side switching element which are totem-pole-connected in that order from the high voltage side between a high voltage side potential and a low voltage side potential; a high side drive circuit that drives the high side switching element; a low side drive circuit that drives the low side switching element; a bootstrap capacitor having first and second terminals and configured to supply a drive voltage to the high side drive circuit, the first terminal connected to a connection point between the high side switching element and the low side switching element, the second terminal connected to a power supply terminal of the high side drive circuit; a bootstrap diode having an anode connected to a power supply and a cathode connected to the second terminal of the bootstrap capacitor and configured to supply a current from the power supply to the second terminal of the bootstrap capacitor; a floating power supply having a reference potential connected to the high voltage side potential; a bootstrap compensation circuit configured to supply a current from the floating power supply to the second terminal of the bootstrap capacitor, when the high side drive circuit turns ON the high side switching element and the low side drive circuit turns OFF the low side switching element; and a current measuring section configured to measure a current that flows from the power supply to the second terminal of the bootstrap capacitor through the bootstrap diode, wherein the bootstrap compensation circuit is further configured to supply the current from the floating power supply to the second terminal of the bootstrap capacitor, when the current measured by the current measuring section is smaller than a predetermined value.