Hitachi, Ltd.

Hitachi Vlsi Engineering Corp.

Hitachi Ulsi Engineering Corp.

Hideki Tsunoda

Isao Yoshida

Kozo Sakamoto

Masatoshi Morikawa

Masayoshi Kobayashi

Tetsuo Iijima

Shigeo Ohtaka

Shigeo Otaka

Ken Uchid

Harutora Shono

An improvement in conditions that protective functions of an insulated gate semiconductor device with a protection circuit incorporated therein are performed, an improvement in the cutoff of heating, the prevention of malfunctions and an improvement in ease of usage can be achieved. The insulated gate semiconductor device of the present invention comprises a power insulated gate semiconductor element (M9), at least one MOSFET (M1 through M7) for a protection circuit, for controlling the power insulated gate semiconductor element, a constant-voltage circuit using forward voltages developed across diodes (D2a through D2f) for the constant-voltage circuit, and voltage restricting diodes (D1 and D0a through D0d) for controlling the upper limit of a power supply voltage of the constant-voltage circuit. Power to be supplied to the voltage restricting diodes is supplied from an external gate terminal of the power insulated gate semiconductor element. The present invention can bring about an advantageous effect that an improvement in reliability of the insulated gate semiconductor device and an improvement in the ease of use can be achieved.

Insulated gate semiconductor device and driving circuit device and

In a semiconductor device including a power MOSFET (M.sub.0) for the output stage, a temperature detection circuit produces an output signal upon detecting an abnormal rise in the chip temperature, the signal turns on a set input element (M.sub.1) in a latch circuit so that the latch circuit becomes a set state, the set output of the latch circuit turns on a control element (M.sub.5), causing the power MOSFET to become non-conductive so that it is protected from destruction. The latch circuit is not brought to a reset state even if the external gate terminal of the device is brought to zero volt. With a voltage outside the range of the normal input signal, e.g., a large negative voltage, being applied to the external gate terminal, the gate capacitance of the control element (M.sub.5) discharges, and consequently the latch circuit is brought to the reset state and the protective operation is cancelled. The semiconductor device is further provided with an external reset terminal, and the protective operation can also be cancelled through the application of a reset signal to the external reset terminal. The semiconductor device is protected from destruction and also from deterioration of characteristics of the power MOSFET (M.sub.0), and yet the protective operation is not cancelled erroneously by the normal input signal.

Semiconductor device having a protection circuit, and electronic system

Growing community of inventors

Akishima, Japan

Hideki Tsunoda