An electrostatic discharge protection circuit to maintain the adjustable voltage

The present invention relates to an integrated circuit chip electrostatic discharge protection circuit, and more particularly relates to a transient triggered ESD protection circuit to maintain the adjustable voltage. The sustain voltage adjustable electrostatic discharge protection circuit comprising transient bleed device and SCR trigger module, the sustain voltage adjustable ESD protection circuit further comprises a sustain voltage regulating module; a sustain voltage regulation module, and said thyristor is connected, comprising: a resistor R2, a capacitor C2, inverter inverters INV1, and the PMOS transistor Mp1 and MP2. Provided herein sustain voltage adjustable electrostatic discharge protection circuit, to ensure that the chip in the non-operating state, the sustain voltage much lower than the supply voltage, electrostatic discharge to more fully charge; chip during the working state, the power supply voltage is greater than the sustain voltage in order to avoid latch-up.