Panasonic Intellectual Property Management Co., Ltd.

Panasonic Corporation

Yusuke Kinoshita

Hidetoshi Ishida

Takashi Ichiryu

Yasuhiro Yamada

Satoshi Tamura

Satoshi Nakazawa

Masanori Nomura

Hidekazu Umeda

Ryosuke Maeda

Tetsuzo Ueda

Ryusuke Kanomata

Yoshiharu Anda

Hiroaki Ueno

Manabu Yanagihara

Masahiro Hikita

Hiroyuki Handa

Takahiro Sato

Hiroto Yamagiwa

Yuji Kudoh

Yuta Nagatomi

An on-state voltage measurement circuit includes a detecting switch element, a control unit, a resistive element, and a voltage detection unit. The control unit includes a signal output terminal and a reference potential terminal and controls the detecting switch element. The resistive element is connected between a source terminal of the detecting switch element and the reference potential terminal. A resistance value of the resistive element is greater than an on-state resistance of the detecting switch element. The control unit turns the detecting switch element on when the semiconductor switch element is turned on. The voltage detection unit detects, based on a voltage across the resistive element when the semiconductor switch element and the detecting switch element are both on, the on-state voltage of the semiconductor switch element connected between a drain terminal of the detecting switch element and the reference potential terminal.

On-state voltage measurement circuit

Current collapse of a normally-on type dual-gate bidirectional switch is suppressed. Dual-gate bidirectional switch includes first gate, first source, second gate, and second source. Control system includes first gate drive circuit, second gate drive circuit, and controller. Controller controls first gate drive circuit and second gate drive circuit. At the time of turning on dual-gate bidirectional switch and when the potential of first source is lower than the potential of second source, controller applies a first positive voltage for a first period between first gate and first source from first gate drive circuit, and applies a voltage smaller than the first positive voltage after the first period has elapsed.

Control system and control method for dual-gate bidirectional switch

A semiconductor device includes: a substrate; a first nitride semiconductor layer above the substrate; a second nitride semiconductor layer above the first nitride semiconductor layer and being greater than the first nitride semiconductor layer in band gap; and a first field-effect transistor including a first source electrode, a first drain electrode, and a first gate electrode that are above the second nitride semiconductor layer, the first source electrode and the first drain electrode being separated from each other, the first gate electrode being disposed between the first source electrode and the first drain electrode. The first field-effect transistor includes a third semiconductor layer that is above the second nitride semiconductor layer in part of a region between lower part of the first source electrode and the first gate electrode, and is separated from the first gate electrode. The third semiconductor layer and the first source electrode are electrically connected.

Semiconductor device

In a switch system, a voltage clamping element is connected to a semiconductor switch in parallel. An active clamping circuit is connected between a control terminal and a first main terminal of the semiconductor switch. The active clamping circuit includes a first diode, a second diode, and a control switch. A second anode of the second diode is connected to a first anode of the first diode. The control switch is connected between the first anode of the first diode and the control terminal of the semiconductor switch. A second control unit controls the control switch. A breakdown voltage of the first diode is smaller than a clamp voltage of the voltage clamping element.

Switch system

A gate drive circuit includes: an input terminal; a first circuit path inserted into a line connecting the input terminal and a gate of a power transistor; a second circuit path connected in parallel to the first circuit path; and a third circuit path connected in parallel to the second circuit path. The first circuit path includes a gate resistor (Rgon). The second circuit path includes a first capacitor and a first resistor connected in series. The third circuit path includes a second capacitor and a second resistor connected in series. The second capacitor has a capacitance value greater than a capacitance value of the first capacitor. The second resistor has a resistance value greater than a resistance value of the first resistor. The gate resistor (Rgon) has a resistance value greater than the resistance value of the second resistor.

Gate drive circuit, and semiconductor breaker

A control circuit controls a switching element including a gate and a source corresponding to the gate. The control circuit includes an inductor, a circuit element, and a resistor. The inductor is connected between the gate and the source of the switching element. The circuit element is connected in series to the inductor between the gate and the source. The circuit element allows an electric current to flow therethrough in response to generation of electromotive force in the inductor. The resistor is connected in parallel to the inductor and the circuit element between the gate and the source.

Control circuit and switch device

Provided are a determination device and a switch system capable of suppressing a power loss of a semiconductor switch. Determination device is used for semiconductor switch. Semiconductor switch includes junction field-effect transistor having gate and source corresponding to gate. Determination device includes resistor and determination circuit. Resistor has a first end and a second end. The first end of resistor is connected to gate. Determination circuit determines that overcurrent is flowing through semiconductor switch when there is a predetermined change in gate-source voltage of junction field-effect transistor in a range smaller than gate drive voltage provided between the second end of resistor and source.

Determination device and switch system equipped therewith

A power loss of a switching device is suppressed. Circuit for a switching device is used in switching device. Switching device includes first path and second path. First path includes first field effect transistor and first inductor. Second path includes second field effect transistor and second inductor. First path and second path are connected in parallel to power supply. A first maximum current that is a maximum current during conduction of first field effect transistor is smaller than a second maximum current that is a maximum current during conduction of second field effect transistor. Circuit for a switching device includes processing part. Processing part executes a specific operation according to a voltage difference between voltage across first inductor and voltage across second inductor.

Circuit for switching device, switching system, and processing method for switching device

A bidirectional switch module includes a plurality of bidirectional switches and a mount board. Each of the plurality of bidirectional switches includes a first source electrode, a first gate electrode, a second gate electrode, and a second source electrode. On the mount board, the plurality of bidirectional switches are mounted. In the bidirectional switch module, the plurality of bidirectional switches are connected in parallel.

Bidirectional switch module and bidirectional switch

A GaN layer is formed over the substrate. An AlGaN layer is formed on the GaN layer. A first source electrode, a first gate electrode, a second gate electrode, and a second source electrode are formed on or over the AlGaN layer. A first p-type AlGaN layer where 0≤x1<1 is interposed between the first gate electrode and the AlGaN layer. A second p-type AlGaN layer where 0≤x2<1 is interposed between the second gate electrode and the AlGaN layer. The substrate is electrically insulated from all of the first source electrode, the second source electrode, the first gate electrode, and the second gate electrode. The bidirectional switch further includes a terminal used to connect the substrate to a fixed potential node. The terminal is connected to the substrate.

Bidirectional switch, electrical device, and multi-level inverter

A substrate electric potential stabilization circuit is configured to be connected to a bidirectional switch element including a first main electrode, a second main electrode, and a backside electrode. The stabilization circuit includes a first switch connected to the first main electrode and the backside electrode in series between the first main electrode and the backside electrode, a second switch connected to the second main electrode and the backside electrode in series between the second main electrode and the backside electrode, and a through-current prevention circuit configured to prevent the first switch and the second switch from being turned on simultaneously. The substrate electric potential stabilization circuit prevents a through-current flowing in this circuit.

Substrate electric potential stabilization circuit and bidirectional switch system

A switch system includes a bidirectional switch, a first gate driver circuit, a second gate driver circuit, a control unit, a first decision unit, and a second decision unit. The bidirectional switch includes a first source, a second source, a first gate, and a second gate. The first decision unit determines, based on a voltage at the first gate and a first threshold voltage, a state of the first gate in a first period in which a signal to turn OFF the first gate is output from the control unit to the first gate driver circuit. The second decision unit determines, based on a voltage at the second gate and a second threshold voltage, a state of the second gate in a second period in which a signal to turn OFF the second gate is output from the control unit to the second gate driver circuit.

A speed-up circuit is configured to be provided between a power supply terminal and a gate of a semiconductor switching element. An impedance element is configured to be provided between a signal input terminal and a node, the node being between the speed-up circuit and the gate of the semiconductor switching element. In the speed-up circuit, a second field effect transistor is connected in series to a first field effect transistor and is configured to be connected to the gate of the semiconductor switching element. The impedance element has an impedance higher than an impedance of the speed-up circuit when both the first field effect transistor and the second field effect transistor are in an ON state.

Growing community of inventors

Kyoto, Japan

Yusuke Kinoshita