Panasonic Intellectual Property Management Co., Ltd.

Panasonic Semiconductor Solutions Co., Ltd.

Takahiro Uehara

Takuya Ishii

Takeshi Tanaka

Hiroyuki Handa

Atsushi Kitagawa

Hideyuki Kihara

Hiroshi Yajima

Yoshihito Kawakami

Ginga Katase

A driver circuit which is supplied with a positive power supply voltage, a negative power supply voltage, and an input signal, and drives a switching element including a control terminal according to the input signal includes: a first output terminal connected to the control terminal via a first impedance circuit, and outputs the positive power supply voltage or the negative power supply voltage according to the input signal, to charge the control terminal and put the switching element into an ON state; a negative power supply terminal supplied with the negative power supply voltage; a negative voltage switch having a first end connected to the negative power supply terminal; a third output terminal connected to a second end of the negative voltage switch and to the control terminal via a second impedance circuit; and a first discharge switch disposed between the negative power supply terminal and the first output terminal.

Driver circuit, switching control circuit, and switching device

A switching circuit includes: a drive power supply; a first transistor and a second transistor; a drive signal source; and a drive circuit. Each of the first transistor and the second transistor includes: a drain electrode and a source electrode in which a main current flows when a corresponding one of the first transistor and the second transistor is ON; a first source terminal for passing the main current; and a second source terminal. Here, the first source terminal is connected to the source electrode at an impedance lower than an impedance of the second source terminal.

Switching circuit

A constant-voltage circuit having an overcurrent protection circuit which includes: a first sense transistor, one main terminal connected to an input terminal of the constant-voltage circuit and a control terminal connected to a control terminal of an output transistor generates a current corresponding to an output current from the output transistor; a voltage level adjusting circuit configured to generate a voltage corresponding to a voltage of a main terminal of the output transistor at an output terminal side of the constant-voltage circuit by extracting a current that is not affected by a change in the output current from the output transistor, and adjust a voltage of another main terminal of the first sense transistor such that the adjusted voltage becomes equal to the generated voltage; and a protection circuit to control a control voltage applied from an error amplifier to the control terminal of the output transistor.

Constant-voltage circuit

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Kyoto, Japan

Takahiro Uehara