Abstract: There are provided a plurality of drive circuits (103 U, 103 L) for driving respective plural switching devices constituting upper arms and lower arms, a power supply circuit for supplying a power supply to the plurality of drive circuits, and a discharge circuit for discharging a capacitor. The power supply circuit includes a first transformer (201U) for the upper arms, and a second transformer (201L) for the lower arms, which include a primary winding connected in parallel to a DC power supply. The first transformer and the second transformer include a secondary winding for supplying a power supply to the drive circuits and for supplying a power supply to a low-voltage circuit (110). Each of the first transformer and the second transformer includes a feedback winding for outputting the voltage output to the drive circuits, to a power supply control IC. The discharge circuit (120) is driven by a power supply supplied from the feedback winding.

Abstract: In a gate drive circuit, a first and second gate drives IC includes an INA terminal and an INB terminal to which a PWM signal is input, a gate output terminal that outputs a gate drive signal, and an OSFB terminal that outputs a feedback signal of the gate drive signal, and they are configured to output a gate drive signal in an ON state when the input of the INA terminal and the INB terminal is (ON, OFF). In the first gate drive IC, a first PWM signal is input to the INA terminal, and a second PWM signal is input to the INB terminal, and in the second gate drive IC, the second PWM signal is input to the INA terminal, and the first PWM signal is input to the INB terminal. The first diode includes a cathode side connected to the INB terminal of the second gate drive IC and an anode side connected to the OSFB terminal of the first gate drive IC.

Abstract: There are provided a plurality of drive circuits (103 U, 103 L) for driving respective plural switching devices constituting upper arms and lower arms, a power supply circuit for supplying a power supply to the plurality of drive circuits, and a discharge circuit for discharging a capacitor. The power supply circuit includes a first transformer (201U) for the upper arms, and a second transformer (201L) for the lower arms, which include a primary winding connected in parallel to a DC power supply. The first transformer and the second transformer include a secondary winding for supplying a power supply to the drive circuits and for supplying a power supply to a low-voltage circuit (110). Each of the first transformer and the second transformer includes a feedback winding for outputting the voltage output to the drive circuits, to a power supply control IC. The discharge circuit (120) is driven by a power supply supplied from the feedback winding.

Abstract: Even when a large current is intentionally flowed during a high-temperature conduction of a semiconductor element, there is a problem in that an overcurrent state is detected to stop current. In the present invention, an overcurrent detector 4 detects overcurrent when an input voltage Vin reaches a threshold voltage Vth, and outputs an overcurrent detection signal c to a gate driving unit 3. On the other hand, when a temperature detection signal a and a current control signal b are input, a transistor 52 is conducted, and the input voltage Vin of the overcurrent detector 4 becomes zero. In this case, the input voltage Vin of the overcurrent detector 4 does not reach the threshold voltage Vth. Therefore, the output of the drive signal output from the gate driving unit 3 is not stopped. For this reason, a large current can flow in a drain current Ids.

Abstract: Even when a large current is intentionally flowed during a high-temperature conduction of a semiconductor element, there is a problem in that an overcurrent state is detected to stop current. In the present invention, an overcurrent detector 4 detects overcurrent when an input voltage Vin reaches a threshold voltage Vth, and outputs an overcurrent detection signal c to a gate driving unit 3. On the other hand, when a temperature detection signal a and a current control signal b are input, a transistor 52 is conducted, and the input voltage Vin of the overcurrent detector 4 becomes zero. In this case, the input voltage Vin of the overcurrent detector 4 does not reach the threshold voltage Vth. Therefore, the output of the drive signal output from the gate driving unit 3 is not stopped. For this reason, a large current can flow in a drain current Ids.