An electrostatic discharge protection circuit

Abstract

The present invention discloses an electrostatic discharge protection circuit, comprising a diode and a N-type metal-oxide-semiconductor (NMOS) transistor. The diode locating on a N-well comprises an high P-doping concentration region and an nonadjacent high N-doping concentration region. The NMOS transistor, locating on a P-well, comprises a drain, a source and a gate, and the drain and the source are formed by the high N-doping concentration region. Wherein the P-well further comprises a high P-doping concentration region near the source, the drain of the NMOS is electrically connected to the high N-doping concentration region of the diode, the source of the NMOS and the adjacent high P-doping concentration region are electrically connected to a ground, the gate of the NMOS transistor electrically connected to a trigger point. Accordingly, the electrostatic discharge protection circuit has a low parasitic capacitance, wide operating voltage range and high electrostatic discharge (ESD) capability for resolving the problems about the ESD of the RX pins.

Description

technical field [0001] The invention relates to an electrostatic discharge protection circuit, in particular to an electrostatic discharge protection circuit using a silicon controlled rectifier, which has low stray capacitance, low trigger voltage, high tolerance voltage operating range and high ESD capability. Background technique [0002] In order to prevent integrated circuit (Integrated circuit, IC) from being damaged by Electrostatic discharge (ESD) bombardment in the process of manufacturing, production and use, it is necessary to add ESD protection on any path connected to the bonding wire circuit, in order to conduct the ESD current to avoid damage to the internal circuit. [0003] Generally speaking, protection circuits can be classified into diodes, metal oxide semiconductor (MOS) transistors, silicon controlled rectifiers (Silicon Controlled Rectifier, SCR), etc. Among them, the silicon controlled rectifier has the highest ESD current conduction capability under...

AI Technical Summary

Problems solved by technology

However, using a diode as an ESD protection circuit can only provide forward ESD current protection, so it is very easy to cause internal components to collapse due to excessive cross-voltage, and then damage the diode; and with the miniaturization of the manufacturing process, the breakdown voltage of the components themselves It also decreases, which increases the difficulty of design

[0008] In addition, because the receiving terminal pin (RX pin) will have a signal like a swing (Swing), so the trigger voltage cannot be too low, and a situation similar to clipping will occur.

Images