High-voltage ESD protective circuit

Abstract

The invention provides a high-voltage ESD protective circuit which is used for discharging ESD current that flows from an IO PAD. The high-voltage ESD protective circuit at least comprises the components of a GDPMOS discharging unit which is arranged between a power supply and the IO PAD; an auxiliary discharging unit which is arranged between the IO PAD and ground and is connected with the GDPMOS discharging unit; and a GGNMOS discharging unit which is connected with the auxiliary discharging unit, wherein the auxiliary discharging unit is used for supplying an auxiliary discharging path of the GGNMOS discharging unit. The auxiliary discharging unit of the invention can supply the auxiliary discharging path of the GGNMOS discharging unit and improves ESD capability. By means of the stacked structure for aiming at high-voltage process, ESD capability of the circuit can be improved, and furthermore triggering voltage and noise resistance of the whole high-voltage ESD protective circuit can be improved, thereby preventing misoperation of the whole high-voltage ESD protective circuit caused by noise.

Description

technical field [0001] The invention relates to the technical field of ESD, in particular to a high-voltage ESD protection circuit. Background technique [0002] The ESD (Electro-Static discharge, electrostatic discharge) phenomenon poses a huge threat to the reliability of integrated circuits, and using on-chip semiconductor devices to form a protection circuit is an important means to improve ESD protection. Existing ESD protection circuits are usually arranged on the IO PAD (input and output pad) of the integrated circuit and the main circuit and at the input port of the power supply voltage. [0003] In high voltage process, common ESD protection circuits such as figure 1 As shown, among them, due to the limitation of the defect of the first high-voltage NMOS transistor HVNMOS1 itself, its ESD capability is lower than that of the first high-voltage PMOS transistor HVPMOS1, which is a short board in the ESD protection circuit, resulting in poor ESD capability of the enti...

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Problems solved by technology

[0007] In view of the above-mentioned shortcoming of prior art, the purpose of the present invention is to provide a kind of high-voltage ESD protection circuit, is used to solve the ESD ability of ESD protection circuit in the prior art is relatively poor, the trigger voltage at IO PAD place is low, and ESD The anti-noise ability of the protection circuit is poor, which may cause malfunctions

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