Denso Corporation

Hisashi Takasu

Tomonori Kimura

Atsushi Kobayashi

Takanari Sasaya

Takeshi Inoue

Michiru Takahashi

A semiconductor apparatus includes a switching device, a voltage detection circuit, a switch circuit, and a control circuit. The voltage detection circuit outputs a detection voltage according to a voltage applied between the first and second terminals of the switching device. The switch circuit is provided in series with a gate drive wire connected to the gate terminal of the switching device and switches between a high impedance state and a low impedance state according to a control signal. The control circuit outputs the control signal to put the switch circuit into the low impedance state when the detection voltage is not greater than a predetermined threshold voltage and outputs the control signal to put the switch circuit into the high impedance state when the detection voltage is greater than the threshold voltage.

Semiconductor apparatus

A power semiconductor device driving circuit includes a gate control terminal, which is provided at a position separated from a drain terminal of a power semiconductor device by a predetermined distance so that electric discharge is generated between the drain terminal and the gate control terminal at the time of generation of surge. A surge voltage is applied to the gate control terminal due to this discharge, the gate of the power semiconductor device is charged to turn on and absorb the surge energy. Thus it becomes possible to suppress the surge voltage applied to the drain terminal and prevent breakdown of the power semiconductor device.

Power semiconductor device driving circuit

Four energization switching devices and positive/negative switching devices are controlled to form a path charging a positive capacitor; a path connecting a power supply with the positive capacitor in series and energizing an inductor to charge a control terminal of a target switching device; a path charging the control terminal using electromagnetism in the inductor; a path supplying circulating current to the power supply when potential of the control terminal becomes higher than voltage of the power supply; a path charging a negative capacitor; a path connecting the power supply with the negative capacitor in series and energizing the inductor to discharge the control terminal; a path discharging the control terminal using electromagnetism in the inductor; and a path supplying circulating current to the power supply when potential of the control terminal becomes lower than potential of a negative terminal of the power supply.

Semiconductor switching device drive circuit

The control apparatus is for controlling a power conversion apparatus with a chopper circuit including at least one voltage-controlled type switching element provided with a drive circuit, and a coil to generate back electromotive force. The control apparatus includes a function of outputting an operation command signal to the drive circuit to control an output voltage of the power conversion apparatus, a second function of setting, on the basis a current flowing through the switching element, a switching speed of the switching element to such a value that noise exceeding a withstand voltage between a conduction control terminal and an output terminal of the switching element can be prevented from occurring when the switching element is switched, and a third function of adjusting the drive circuit to drive the switching element such that the switching element is switched at the switching speed set by the second function.

Control apparatus for controlling power conversion apparatus

A method for controlling a vertical type MOSFET in a bridge circuit is provided to reduce diode power loss and improve a reverse recovery characteristic. The method includes controlling a forward voltage of a built-in diode of the vertical type MOSFET to be a first forward voltage by setting a gate voltage of the vertical MOSFET to a first gate voltage, so that the vertical type MOSFET is switched into a first off mode; and controlling the forward voltage of the built-in diode of the vertical type MOSFET to be a second forward voltage by setting the gate voltage of the vertical MOSFET to a second gate voltage, so that the vertical type MOSFET is switched into a second off mode.

Method for controlling vertical type MOSFET in bridge circuit

A demodulator includes a count section, a synchronization timing setting section, and a code judgment section. The count section has four counters that count a number of waves of an FSK-modulated digital signal at different timing within a bit time width. The synchronization timing setting section designates a synchronized timing signal based on the count value of the count section. Then, the code judgment section compares the count value with a threshold value to judge the signal level, thereby decoding the digital signal.

Growing community of inventors

Nishio, Japan

Hisashi Takasu