US 8,427,798 B2Granted

Semiconductor integrated circuit device

AssigneeKabushiki Kaisha Toshiba

InventorsHiroshi Shimomura, Masaru Numano

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Abstract

In one embodiment, a semiconductor integrated circuit includes a power source circuit connected to a terminal of a first high potential side power source and outputs a voltage of a second high potential side power source, and an output transistor outputting an output signal to an output terminal. A cathode of a first diode is connected to the terminal of the first high potential side power source and an anode thereof is connected to the output terminal. A current source and a capacitor are connected between a terminal of the second high potential side power source and the terminal of a low potential side power source. A signal from a connection node of the current source and the capacitor and a control signal are inputted to a logic circuit, and the logic circuit outputs a signal obtained by a logic operation to the control terminal of the output transistor.

Claims19

Dependent claims

A semiconductor integrated circuit device, comprising:

a power source circuit that is connected to a terminal of a first high potential side power source and that outputs a voltage of a second high potential side power source;
an output transistor that includes a first terminal, a second terminal that is connected to a terminal of a low potential side power source, and a control terminal and that outputs an output signal from the first terminal to an output terminal;
a first diode that includes a cathode connected to the terminal of the first high potential side power source and an anode connected to the output terminal;
a connection circuit that is connected between a terminal of the second high potential side power source and the terminal of the low potential side power source, and in which a current source and a capacitor are arranged in a cascade connection;
and
a logic circuit to which a signal obtained from a connection node of the current source and the capacitor and a control signal that controls on/off operations of the output transistor are inputted and which outputs a signal obtained by a logic operation to the control terminal of the output transistor.

3 more elements

A semiconductor integrated circuit device, comprising:

a power source circuit that is configured to receive a voltage of a first high potential side power source and to output a voltage of a second high potential side power source based on the voltage of the first high potential side power source;
an internal circuit that is configured to output a first control signal based on a received input signal and based on the voltage of the second high potential side power source;
a connection circuit that is configured to output a second control signal based on the voltage of the second high potential side power source;
a logic circuit that receives the first and second control signals, and that performs a logical operation based on the first and second control signals to output a logic signal;
and
an output circuit that is configured to receive the logic signal from the logic circuit, be turned on when the logic signal indicates the presence of a surge voltage at a device output terminal, and, when turned on, dissipate the surge voltage to a side of the low potential side power source to thereby protect the internal circuit from the surge voltage.

3 more elements

Dependencies are inferred from the claim text.