US 5,706,156 A · Semiconductor device having an ESD protective circuitry

Abstract

A semiconductor device has a protective circuitry including a common discharge line, a first protective device connected between one of input/output terminals and the discharge line, and a second protective device connected between one of Vcc and ground terminals and the discharge line. The second protective device has an on-resistance as much as 1/2 of the on-resistance of the first protective device. Each of the power terminals and ground terminals generally has a large capacitance to accumulate a large amount of electric charge during a CDM test after charging of the semiconductor device as a whole. The low on-resistance prevents the inner circuit and input/output buffers of the semiconductor device from being applied with a higher potential during subsequent grounding of the semiconductor device in the CDM test.

Claims18

Dependent claims

A semiconductor device, comprising:

a substrate;
an inner circuit formed on said substrate;
an external terminal group disposed for said inner circuit and including a plurality of first terminals and a plurality of second terminals;
and
a protective circuitry including:
a common discharge line;
a first protective device connected between each of said first terminals and said common discharge line;
and
a second protective device connected between each of said second terminals and said common discharge line, each of said first terminals having a first parasitic capacitance, each of said second terminals having a second parasitic capacitance larger than said first parasitic capacitance,
said first protective device having a first on-resistance, said second protective device having a second on-resistance smaller than said first on-resistance.

7 more elements

Dependencies are inferred from the claim text.

Semiconductor device having an ESD protective circuitry

Life of this patent

Semiconductor device having an ESD protective circuitry

Life of this patent

Abstract

Claims18