Abstract: A power semiconductor device includes a conductive board and a switching element mounted on the conductive board and electrically connected thereto. The power semiconductor device also includes an integrated circuit mounted on the conductive board at a distance from the switching element and electrically connected thereto. The switching element turns ON/OFF a connection between first and second main electrodes in response to a control signal inputted to a control electrode. The integrated circuit includes a control circuit which controls ON/OFF the switching element and a back side voltage detection element which detects a voltage of the back side of the integrated circuit.

Abstract: In a timer circuit of a semiconductor circuit including a current source driven by a power supply voltage, the current source outputs a current dependent on the power supply voltage, and outputs a reference voltage obtained when the power supply voltage is dropped by a predetermined drop voltage. A capacitor is charged with electric charges by the current outputted from the current source. The comparator compares a voltage across the capacitor with the reference voltage from the current source, and outputs an output signal when a voltage across the capacitor is equal to or higher than the reference voltage. The timer circuit outputs an output signal after a delay time, from a timing when supply of the power supply voltage is started, to a timing when the voltage across the capacitor rises substantially in proportion to an elapsed time by charging the capacitor and reaches the reference voltage.

Abstract: The power semiconductor device of the present invention is provided with a conductive board 3, a switching element 1 mounted on the conductive board 3 and electrically connected thereto and an integrated circuit 4 mounted on the conductive board 3 at a distance from the switching element 1 and electrically connected thereto. The switching element 1 turns ON/OFF a connection between first and second main electrodes in response to a control signal inputted to a control electrode. The integrated circuit 4 has a control circuit 72 which controls ON/OFF of the switching element 1 and a back side voltage detection element 31 which detects a voltage of the back side of the integrated circuit 4.

Abstract: A gate discharge resistor part is connected to the gate of an IGBT (Insulated Gate Bipolar Transistor). A timer circuit has its output connected to the input of the gate discharge resistor part and the input of a gate driving circuit. When an ON signal for driving the IGBT into an ON state stays input over a predetermined time period, the timer circuit outputs an H-level signal to the gate discharge resistor part and gate driving circuit. The gate driving circuit drives the IGBT into the OFF state based on the signal from the timer circuit. The gate discharge resistor part changes its resistance from a value given by a first resistor to a value given by a composite resistance of the first and second resistors.

Abstract: In a timer circuit of a semiconductor circuit including a current source driven by a power supply voltage, the current source outputs a current dependent on the power supply voltage, and outputs a reference voltage obtained when the power supply voltage is dropped by a predetermined drop voltage. A capacitor is charged with electric charges by the current outputted from the current source. The comparator compares a voltage across the capacitor with the reference voltage from the current source, and outputs an output signal when a voltage across the capacitor is equal to or higher than the reference voltage. The timer circuit outputs an output signal after a delay time, from a timing when supply of the power supply voltage is started, to a timing when the voltage across the capacitor rises substantially in proportion to an elapsed time by charging the capacitor and reaches the reference voltage.

Abstract: A gate discharge resistor part is connected to the gate of an IGBT (Insulated Gate Bipolar Transistor). A timer circuit has its output connected to the input of the gate discharge resistor part and the input of a gate driving circuit. When an ON signal for driving the IGBT into an ON state stays input over a predetermined time period, the timer circuit outputs an H-level signal to the gate discharge resistor part and gate driving circuit. The gate driving circuit drives the IGBT into the OFF state based on the signal from the timer circuit. The gate discharge resistor part changes its resistance from a value given by a first resistor to a value given by a composite resistance of the first and second resistors.