摘要 |
An electro-static discharge protection circuit includes a thyristor mode ensuring circuit and a thyristor rectifier circuit. The thyristor mode ensuring circuit includes a capacitive element connected between a higher potential line and a lower potential line, and ensures a constant and sufficient capacity independently of the number of input/output signal bits, even when the number of input/output signal bits is a theoretical minimum, i.e. 1, so that a surge current induced by electro-static discharge (ESD) applied to an output pad is injected into the first capacitive element to charge it. Thus, by means of the current caused by the surge current, the thyristor rectifier circuit is triggered into a thyristor mode, which allows the surge current to flow to the lower potential line through the thyristor rectifier circuit, protecting circuitry against the surge current.
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