Patent ID: 7498615

Claim:
An electro-static discharge protection circuit, comprising: a first thyristor rectifier circuit that is electrically coupled between first internal circuitry and a first signal input/output section to which a potential that corresponds to either an input signal to the first internal circuitry or an output signal from the first internal circuitry is to be applied, and also electrically coupled between a higher potential line and a lower potential line; and a first thyristor mode ensuring circuit that is electrically coupled between the higher potential line and the lower potential line, and also electrically coupled to the first thyristor rectifier circuit, in order to trigger the first thyristor rectifier circuit into a thyristor mode by means of a surge current applied to the first signal input/output section so that the surge current flows into the lower potential line through the first thyristor rectifier circuit in order to protect the first internal circuitry from the surge current, the first thyristor mode ensuring circuit comprising an element having a predetermined capacitance that is not stray capacitance.