Kabushiki Kaisha Toshiba

Toshiba Electronic Devices & Storage Corporation

Hideaki Majima

Jun Deguchi

Toshiyuki Yamagishi

Yuichi Sawahara

Katsuyuki Ikeuchi

Yasuyuki Fujiwara

Nau Ozaki

Naotsugu Kako

Yiyao Liu

Yusuke Sato

Yuichi Nakamura

Ichiro Seto

Masahiro Sekiya

Koji Horisaki

Keiji Tsunoda

Yukiyasu Tatsuzawa

Hiroyuki Fujiki

Mitsuyuki Ashida

Tatsuji Ashitani

Yuki Fujimura

Kazuhiro Hiwada

Hisao Kawasato

Motohiro Morisaki

Hideki Yamada

According to an embodiment, a transistor driver circuit includes a driving force limitation circuit and a delay-time adjustment circuit. The driving force limitation circuit operates to maintain a gate potential of a transistor to be driven at a driving force limitation potential when the transistor to be driven is driven. The driving force limitation potential corresponds to a threshold voltage of the transistor to be driven. The delay-time adjustment circuit operates to cause the gate potential to transition to the driving force limitation potential when the driving force limitation circuit is in operation.

Transistor driver circuit and transistor driving method

According to one embodiment, a signal processing circuit includes a first voltage setting circuit that sets a reference voltage on an input side of an isolator, a variable gain amplifier circuit that amplifies an output signal of the isolator, a DC offset adjustment circuit that adjusts an offset of the variable gain amplifier circuit, a second voltage setting circuit that sets a reference voltage on an output side of the isolator, and a control circuit that controls the DC offset adjustment circuit in response to a result of comparison of an output voltage of the variable gain amplifier circuit with an output voltage of the second voltage setting circuit.

Signal processing circuit

According to one embodiment, a degradation detection device includes a driving circuit that supplies a driving signal that controls on/off of an output transistor to the output transistor and an output circuit that compares a value of integral of an output current that is output by the output transistor in an off-state thereof over a predetermined period of time with a predetermined threshold when the output transistor is turned from an on-state thereof to an off-state thereof and outputs a signal that indicates a degradation state of the output transistor depending on a result of such comparison.

Degradation detection device and degradation detection method

According to one embodiment, an inrush current suppression circuit includes a normally-on transistor, a normally-off transistor connected in series with the normally-on transistor, a first drive circuit that drives the normally-on transistor, a second drive circuit that drives the normally-off transistor, a diode connected between an output of the first drive circuit and an output terminal of the normally-off transistor, a first power source smoothing circuit that performs smoothing of a source current to be supplied to the first drive circuit and the second drive circuit, and a switch circuit that switches connection/disconnection of a current path passing through the first power source smoothing circuit.

Inrush current suppression circuit

According to one embodiment, a deterioration checking apparatus includes an inductor that is connected in series to a main current path of a MOS transistor to be checked, and forms a closed loop together with the MOS transistor when the MOS transistor is in an ON-state, a control circuit that controls ON/OFF of the MOS transistor, a current sensor that detects a current released from the inductor, and a calculation circuit that calculates an ON-resistance of the MOS transistor from an attenuation characteristic of a current released from the inductor when the MOS transistor is in an ON-state, and calculates a threshold voltage of the MOS transistor from an attenuation characteristic of a current released from the inductor when the MOS transistor is in an OFF-state. Therefore, it is possible to easily check a deterioration state of the MOS transistor.

Deterioration checking apparatus and deterioration checking

A current detection circuit includes normally-on-type and a first normally-off-type switching elements with main current paths that are connected in series, and a second normally-off-type switching element that has a source and a gate that are connected to a source and a gate of the first normally-off-type switching element and a drain that is connected to a constant current source, and executes a division process by using drain voltages of the two normally-off-type switching elements.

Current detection circuit

A semiconductor device that normally-off drives a first transistor that normally-on drives, the semiconductor device includes a first circuitry, a second circuitry, and a first diode. The first circuitry that is connected with a power supply voltage and a ground voltage, detects the power supply voltage, and outputs a transition state of the power supply voltage. The second circuitry that is connected with the power supply voltage, the ground voltage, the first circuitry, and a second transistor, and outputs a drive voltage of a second transistor connected in series with the first transistor, based on an output of the first circuitry. The first diode having an anode connected with a drive terminal of the first transistor and a cathode connected with an output terminal of the second transistor.

Semiconductor device

According to an embodiment, a current detecting circuit includes: a normally-OFF type second switching element that is cascode-connected to a normally-ON type first switching element that includes a drain for outputting an output current; a normally-OFF type third switching element that is connected in parallel to the second switching element and whose drain is connected to a variable current source; and a comparison circuit that outputs a detection signal in accordance with a comparison result between a drain voltage of the second switching element and a drain voltage of the third switching element.

Current detecting circuit, current detecting system, and power source circuit

According to one embodiment, a current detecting circuit includes: a normally-ON type first switching element that includes a drain, a source, and a gate; a normally-OFF type second switching element including a drain that is connected to the source of the first switching element, a source that is connected to the gate of the first switching element, and a gate; and a differential amplification circuit that outputs a voltage according to a voltage between the drain and the source of the second switching element.

Current detecting circuit

According to one aspect of embodiments, a drive circuit of a normally-ON transistor includes: a normally-OFF transistor that includes a main current path connected in serial to a main current path of the normally-ON transistor; and a buffer circuit that supplies, to a gate of the normally-ON transistor, a control signal for controlling turning ON and OFF of the normally-ON transistor, whose high-voltage side and low-voltage side are biased by a bias voltage supplied from a power source unit.

Drive circuit and drive method of normally-on transistor

According to one embodiment, a drive control circuit includes a first transistor that supplies a current to a gate of an output transistor in response to a drive signal, a second transistor that supplies a current to a capacitor in response to the drive signal, a comparison circuit that compares a gate voltage of the output transistor and a voltage of the capacitor, a control signal generation circuit that generates a control signal in response to an output signal of the comparison circuit and the drive signal, and a third transistor that supplies a current to a gate of the output transistor in response to the control signal.

Growing community of inventors

Tokyo, Japan

Hideaki Majima