Panasonic Intellectual Property Management Co., Ltd.

Panasonic Corporation

Takeshi Azuma

Manabu Yanagihara

Yoshihisa Minami

Takuya Ishii

Daijiro Arisawa

Daisuke Yamamoto

Koji Takahashi

Kazuhiro Yahata

Hiroki Akashi

Noboru Negoro

Yoshihito Kawakami

A gate drive circuit that drives a switching element including a first drain, a first source, and a first gate includes: a first terminal to which a gate control signal is input; a gate signal line connecting the first terminal and the first gate; a resistance element inserted in the gate signal line; a capacitance element connected in parallel with the resistance element; a clamp circuit that performs a clamp operation of clamping a voltage between the first gate and the first source to a voltage lower than a threshold voltage of the switching element when the gate control signal indicates an off period of the switching element; and a clamp control circuit that controls whether to prohibit the clamp operation of the clamp circuit in the off period.

Gate drive circuit, gate drive device, high-frequency power supply device, and system

A switch circuit is configured of a first semiconductor element and a second semiconductor element connected in series, and receives a DC voltage of 100 V or more. The drive circuit causes the first semiconductor element or the second semiconductor element to perform a switching operation. The isolated power supply circuit converts a predetermined power supply voltage into an isolated first power supply voltage, and outputs the first power supply voltage to the drive circuit. The isolation signal converter converts a first signal of 6 MHz or more into an isolated first drive signal, and outputs the first drive signal to the drive circuit. The single substrate mounts the isolated power supply circuit and the isolation signal converter. Both the first semiconductor element and the second semiconductor element are wide bandgap semiconductor elements.

Class-D power converter

A switching circuit includes: a normally-off junction field-effect GaN transistor including source, drain, and gate terminals; a drive device of one output type electrically connected to the gate terminal; a first rectifier, between the source terminal and the gate terminal, including an anode on a source terminal side and a cathode on a gate terminal side; a capacitor between a cathode side of the first rectifier and the drive device; a first resistor between the capacitor and the drive device; a second resistor, one side of the second resistor being connected to the drive device, another side of the second resistor being connected between the cathode side of the first rectifier and the capacitor; and a second rectifier including an anode on a capacitor side and a cathode on a drive device side. No resistor is provided between the cathode side of the second rectifier and the drive device.

Switching circuit

A switching circuit includes; a switching element; a driver; a diode connected between a source terminal and a gate terminal of the switching element; a resistor connected between the driver and the gate terminal of the switching element; a series circuit connected in parallel with the resistor, and including a capacitor and a resistor; and a diode including an anode on a side of the gate terminal of the switching element and a cathode on a side of a second output terminal of the driver. The diode is connected in parallel with at least the capacitor out of the capacitor and the resistor connected in series.

Provided is a step up/down converter, in which the inductor current can be easily detected by a simple configuration in any connecting mode of the switches. This comprises a first switch, one end of which is connected to an input power source, and the other end of which is connected to one end of the inductor, a second switch, one end of which is connected to the one end of the inductor, and the other end of which is connected to a reference potential applying unit, a third switch and a fourth switch, one end of which is connected to the other end of the inductor; a capacitor circuit element, connected between the other end of the third switch and the other end of the fourth switch, and configured to generate an output voltage for applying to a load, a detecting resistor, connected between the other end of the second switch and the other end of the third switch, and configured to detect an inductor current flowing through the inductor, and a control circuit configured to perform control from the first switch to the fourth switch based on the inductor current detected by the detecting resistor.

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Osaka, Japan

Takeshi Azuma