# US 10,873,182 B2 · Electrostatic discharge protection circuit and display device applying the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,873,182 B2 - Document ID: US10873182B2 - Status: Granted - Kind: B2 - Application number: 15/743,256 - Filed: 2017-10-20 - Published: 2019-04-18 - Granted: 2020-12-22 - Earliest claimed: 2017-09-14 - Assignees: Hkc Corporation Limited - Applicants: HKC Corporation Limited - Inventors: Huailiang He - Web page: https://patentgrep.com/patent/US10873182B2 ## CPC - H02H 9/046: {responsive to excess voltage appearing at terminals of integrated circuits} - G02F 1/136204: {Arrangements to prevent high voltage or static electricity failures} - H02H 9/04: responsive to excess voltage (lightning arrestors H01C7/12, H01C8/04, H01G9/18, H01T) - H05F 3/02: by means of earthing connections - H10D 89/811: {using FETs as protective elements} - H02H: EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS (indicating or signalling undesired working conditions G01R, e.g. G01R31/00, G08B; locating faults along lines G01R31/08; emergency protective devices H01H) - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS - H05F: STATIC ELECTRICITY; NATURALLY-OCCURRING ELECTRICITY - H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES ## Abstract This application relates to an electrostatic discharge (ESD) protection circuit, includes: a first switch, electrically coupled to a first node through a control end, electrically coupled to a ground node through a first end, and electrically coupled to a signal input node through a second end; a capacitor electrically coupled between the first node and the signal input node; a second switch, electrically coupled to a low level line through a control end and a first end, and electrically coupled to the signal input node through a second end; and a third switch, electrically coupled to a high level line through a control end, and electrically coupled to the first node through a first end, being electrically coupled to the low level line through a second end. ## Claims ### Claim 1 An electrostatic discharge (ESD) protection circuit, comprising: a first switch, electrically coupled to a first node through a control end of the first switch, and electrically coupled to a ground node through a first end of the first switch, and electrically coupled to a signal input node through a second end of the first switch; a capacitor electrically coupled between the first node and the signal input node; a second switch, electrically coupled to a first level line through a control end and a first end of the second switch, and electrically coupled to the signal input node through a second end of the second switch; and a third switch, electrically coupled to a second level line through a control end of the third switch, and electrically coupled to the first node through a first end of the third switch, and electrically coupled to the first level line through a second end of the third switch; wherein when static electricity having a voltage potential that is greater in magnitude than the voltage potential of the second level line is presented on the signal input node, the capacitor adjusts the voltage potential of the first node to turn on the first switch and the third switch, wherein the static electricity then discharges through the first switch towards the ground node and discharges through the third switch towards the first level line. ### Claim 2 (depends on 1) The ESD protection circuit according to claim 1, wherein the first switch, the second switch and the third switch are N-type transistors, the first level line is a low level line, and the second level line is a high level line. ### Claim 3 (depends on 2) The ESD protection circuit according to claim 2, wherein the potential of the first node is equal to that of the low level line, and the first switch is turned off. ### Claim 4 (depends on 2) The ESD protection circuit according to claim 2, wherein the signal input node gets positive-potential static electricity, and when the potential of the positive-potential static electricity is a potential between the high level line and the low level line, the first switch and the third switch are turned off. ### Claim 5 (depends on 1) The ESD protection circuit according to claim 1, wherein the first switch, the second switch and the third switch are P-type transistors, the first level line is a high level line, and the second level line is a low level line. ### Claim 6 (depends on 5) The ESD protection circuit according to claim 5, wherein the potential of the first node is equal to that of the high level line, and the first switch is turned off. ### Claim 7 (depends on 5) The ESD protection circuit according to claim 5, wherein the signal input node gets negative-potential static electricity, and when the potential of the negative-potential static electricity is a potential between the high level line and the low level line, the first switch and the third switch are turned off. ### Claim 8 (depends on 1) The ESD protection circuit according to claim 1, wherein when the potential of the static electricity is a potential between the second level line and the first level line, the capacitor forms an open circuit to down-regulate the potential of the first node. ### Claim 9 (depends on 1) The ESD protection circuit according to claim 1, wherein operating currents of the first switch and the second switch are below 1 μA. ### Claim 10 An electrostatic discharge (ESD) protection circuit, comprising: a first switch, electrically coupled to a first node through a control end of the first switch, and electrically coupled to a ground node through a first end of the first switch, and electrically coupled to a signal input node through a second end of the first switch; a capacitor electrically coupled between the first node and the signal input node; a second switch, electrically coupled to a first level line through a control end and a first end of the second switch, and electrically coupled to the signal input node through a second end of the second switch; and a third switch, electrically coupled to a second level line through a control end of the third switch, and electrically coupled to the first node through a first end of the third switch, and electrically coupled to the first level line through a second end of the third switch; wherein when static electricity having a voltage potential that is greater in magnitude than the voltage potential of the second level line is presented on the signal input node, the capacitor adjusts the voltage potential of the first node to turn on the first switch and the third switch, wherein the static electricity then discharges through the first switch towards the ground node and discharges through the third switch towards the first level line; when the voltage potential of the static electricity is a voltage potential between the first level line and the second level line, the capacitor forms an open circuit to down-regulate the voltage potential of the first node, to turn off the first switch and the third switch; the ground node is electrically coupled to a ground wire or a common voltage wire; and operating currents of the first switch and the second switch are below 1 μA. ### Claim 11 A display device, comprising: a display panel; and an electrostatic discharge (ESD) protection circuit, comprising: a first switch, electrically coupled to a first node through a control end of the first switch, and electrically coupled to a ground node through a first end of the first switch, and electrically coupled to a signal input node through a second end of the first switch; a capacitor electrically coupled between the first node and the signal input node; a second switch, electrically coupled to a first level line through a control end and a first end of the second switch, and electrically coupled to the signal input node through a second end of the second switch; and a third switch, electrically coupled to a second level line through a control end of the third switch, and electrically coupled to the first node through a first end of the third switch, and electrically coupled to the first level line through a second end of the third switch; wherein when static electricity having a voltage potential that is greater in magnitude than the voltage potential of the second level line is presented on the signal input node, the capacitor adjusts the voltage potential of the first node to turn on the first switch and the third switch, wherein the static electricity then discharges through the first switch towards the ground node and discharges through the third switch towards the first level line. ### Claim 12 (depends on 11) The display device according to claim 11, wherein the first switch, the second switch and the third switch are N-type transistors, the first level line is a low level line, and the second level line is a high level line. ### Claim 13 (depends on 12) The display device according to claim 12, wherein the potential of the first node is equal to that of the low level line, and the first switch is turned off. ### Claim 14 (depends on 12) The display device according to claim 12, wherein the signal input node gets positive-potential static electricity, and when the potential of the positive-potential static electricity is a potential between the high level line and the low level line, the first switch and the third switch are turned off. ### Claim 15 (depends on 11) The display device according to claim 11, wherein the first switch, the second switch and the third switch are P-type transistors, the first level line is a high level line, and the second level line is a low level line. ### Claim 16 (depends on 15) The display device according to claim 15, wherein the potential of the first node is equal to that of the high level line, and the first switch is turned off. ### Claim 17 (depends on 15) The display device according to claim 15, wherein the signal input node gets negative-potential static electricity, and when the potential of the negative-potential static electricity is a potential between the high level line and the low level line, the first switch and the third switch are turned off. ### Claim 18 (depends on 11) The display device according to claim 11, wherein when the potential of the static electricity is a potential between the second level line and the first level line, the capacitor forms an open circuit to down-regulate the potential of the first node. ### Claim 19 (depends on 11) The display device according to claim 11, wherein the ground node is electrically coupled to a ground wire or a common voltage wire. ### Claim 20 (depends on 11) The display device according to claim 11, wherein operating currents of the first switch and the second switch are below 1 μA.