Patent ID: 8513985
Filing Date: 2013-08-20
Classification: H03K

Abstract:
1. A drive circuit for a semiconductor switching element serving as a drive-target switching element, comprising: a driving-usage power supply that supplies a drive voltage, which is applied between a control terminal and a potential reference terminal of the drive-target switching element; at least one capacitor that is charged by the driving-usage power supply; a connection changeover unit that is connected between the driving-usage power supply and the capacitor, and that switches a connection form between the driving-usage power supply and the capacitor; a resistor element that is connected to the control terminal of the drive-target switching element; a first switching element and a second switching element that are connected in series with each other, a positive-side diode whose cathode is connected to an end of the first switching element; a negative-side diode whose anode is connected to an end of the second switching element; a backflow path formation element that is connected between the control terminal of the drive-target switching element and the driving-usage power supply, and that is brought into a conductive state when electric potential of the control terminal changes so as to exceed voltage of the driving-usage power supply; and a current conduction control circuit that controls the connection changeover unit, the first switching element and the second switching element to form