Electrostatic discharge protection circuit

Abstract

An electrostatic discharge protection circuit and an input pad are connected and used for dissipating electrostatic discharge current. The electrostatic discharge protection circuit comprises a first conductivity type substrate, a second conductivity type first well located in the substrate and a first conductivity type second well located in the first well. The protection circuit further comprises a diode assembly located in the first well, wherein the diode assembly comprises a first conductivity type first end and a second conductivity type second end. The first end is electrically connected to the input pad. Furthermore, the protection circuit is further provided with a second conductivity type first doping region located in the first well and connected to the input pad electrically and a first conductivity type second doping region located in the substrate, wherein the first doping region is electrically connected to the ground, and a channel for electrostatic discharge current discharging is arranged between the input pad and the second doping region.

Description

technical field [0001] The invention relates to an electrostatic discharge protection circuit, in particular to an electrostatic discharge protection circuit with low leakage current. Background technique [0002] Protecting components from ESD damage has always been a challenge for those skilled in the art. The traditional ESD protection circuit mainly includes a diode connection, one end of which is electrically coupled to the I / O pad, and the other end is connected to the ground for Dissipate high current through a circuit. Generally speaking, a diode junction has a well electrically opposite to the substrate to accommodate the two ends of the diode. However, one end of the diode and the well and the substrate form a parasitic bipolar transistor (BJT), which becomes a parasitic bipolar transistor (BJT) during normal operation. , such as the undesired leakage path when the input and output pads are biased with a 10 volt voltage, so the power consumption caused by the elec...

AI Technical Summary

Problems solved by technology

Generally speaking, a diode junction has a well electrically opposite to the substrate to accommodate the two ends of the diode. However, one end of the diode and the well and the substrate form a parasitic bipolar transistor (BJT), which becomes a bipolar transistor (BJT) during normal operation. , such as the leakage path that is undesirable when the input and output pads are biased at 10 volts, so the energy consumption caused by the electrostatic discharge protection circuit becomes a major disadvantage

[0003] In addition to leakage, another challenge to the design of traditional ESD protection circuits is the gradually shrinking layout area. Due to the pursuit of small-sized electronic components, the restrictions on circuit designers are also increasing. In addition to protecting the self-output pads The incoming electrostatic discharge is also necessary for the reverse negative voltage electrostatic discharge, so it is usually necessary to reserve an extra area in the design to add a reverse diode to dissipate the negative voltage electrostatic discharge

However, the sacrificed area will result in a reduction in transistor density

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