Electrostatic discharge protection circuit

Abstract

The invention provides an ESD (electrostatic discharge) protection circuit. The ESD protection circuit comprises a clamping unit, a driving unit, a resistance unit, a switch unit and a capacitance unit. The clamping unit is coupled between a first power source and a second power source; the driving unit is coupled between the clamping unit and a reference node; the resistance unit is coupled between the first power source and the reference node; the switch unit is coupled to the driving unit through the reference node; the capacitance unit is coupled between the switch unit and the second power source. Under a normal operation condition, the driving unit controls the switch unit to be in an off state; under an ESD condition, the driving unit controls the switch unit to be in an on state.

Description

technical field [0001] The invention relates to an electrostatic discharge protection circuit, in particular to an electrostatic discharge protection circuit capable of eliminating gate leakage current. Background technique [0002] Please refer to figure 1 , which is a simplified schematic block diagram of a traditional electrostatic discharge protection circuit 100, wherein the electrostatic discharge protection circuit 100 is an electrostatic discharge clamp circuit (RC-based power-rail ESD clamp circuit) based on a resistive-capacitive conductive rail. The discharge protection circuit 100 includes: a clamping unit 102, a driving unit 104, a resistance unit 106 and a capacitor unit 110, wherein the clamping unit 102 is an N-type metal oxide semiconductor transistor (NMOS), and the driving unit 104 is an inverting device. Under a normal circuit operating condition, the input terminal of the inverter is at a high voltage level, therefore, the output terminal of the invert...

AI Technical Summary

Problems solved by technology

[0003] However, in advanced CMOS process technologies, although MOS capacitors using thinner gate oxide processes occupy less area, thinner gate oxides result in larger gate leakage currents value, therefore, when the capacitor units 110, 210 in the above-mentioned traditional ESD protection circuit 100 and ESD protection circuit 200 are metal oxide semiconductor capacitors with thin gate oxide layers, the capacitor units 110, 210 produce relatively A large gate leakage current may cause the above-mentioned traditional ESD protection circuit 100 and ESD protection circuit 200 or other circuits in the chip to fail to operate normally.

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