US 5,850,094 A · Semiconductor device

Abstract

The present invention relates to a semiconductor device which utilizes a first conduction MOS output transistor 11 as an output transistor. The inventive semiconductor device have a advantage that the occupied area of an electrostatic breakdown preventing circuit is smaller than that of the conventional device, and the resistance against the electrostatic breakdown is better than that of the conventional device, and further an additional manufacturing process is not required, thereby obtaining the semiconductor device with an improved resistance. The inventive device is formed that a second conduction MOS transistor 13 functions as an electrostatic breakdown preventing circuit, with a drain of which being connected to an output terminal 15, and connected in a parallel form with the output transistor.

Claims50

Dependent claims

A semiconductor device comprising:

an output transistor having a first conductive type with one of a source and a drain thereof connected to an output terminal of the semiconductor device, and the other of the source and drain thereof connected to a first power supply;
and
a circuit preventing an electrostatic breakdown for protecting the output transistor from the electrostatic breakdown introduced by an electrostatic surge current;
wherein said circuit comprises a semiconductor transistor having a second conductive type and including a first impurity layer which is a first electrode of the second conductive type connected to the first power supply, a second impurity layer which is a second electrode of the second conductive type connected to the output terminal, and a third electrode, so that said circuit is connected across said output transistor between the first power supply and the output terminal.

1 more element

A semiconductor device comprising:

a first output transistor of a first conductive type connected to an output terminal and a first power supply;
a second output transistor of a second conductive type connected to said output terminal and a second power supply;
and
a first circuit preventing an electrostatic breakdown for protecting said first output transistor when an electrostatic surge current is present;
wherein said first circuit is a first semiconductor transistor of the second conductive type connected across said first output transistor, a first electrode of said first semiconductor transistor being connected to said output terminal, a second electrode of said first semiconductor transistor being connected to said first power supply, and said first semiconductor transistor including a third electrode.

2 more elements

Dependencies are inferred from the claim text.

Semiconductor device

Life of this patent

Semiconductor device

Life of this patent

Abstract

Claims50