# US 2018/0323609 A1 · Voltage triggered edge insensitive protection circuit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0323609 A1 - Document ID: US20180323609A1 - Status: Published application - Kind: A1 - Application number: 15/588,309 - Filed: 2017-05-05 - Published: 2018-11-08 - Earliest claimed: 2017-05-05 - Assignees: Synaptics Incorporated - Applicants: Synaptics Incorporated - Inventors: Abhijat GOYAL - Web page: https://patentgrep.com/patent/US20180323609A1 ## CPC - H02H 9/046: {responsive to excess voltage appearing at terminals of integrated circuits} - G06F 3/044: by capacitive means - 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) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract Embodiments of disclosure generally relate to integrated circuits (ICs) and, more particularly, a voltage-triggered edge-insensitive electrostatic discharge (ESD) clamp for protection of ICs. An example trigger circuit is provided for controlling a current shunt in an IC. The trigger circuit generally includes a comparison circuit configured to compare a monitored voltage to a reference voltage and output a signal indicating when the monitored voltage reaches or exceeds the reference voltage; and a shunt circuit configured to shunt the current based on receiving the signal from the comparison circuit. The voltage-triggered edge-insensitive clamp provides a single protection circuit that protects against all types of ESD and/or electrostatic overstress (EOS) events. ## Claims ### Claim 1 A trigger circuit for controlling a current shunt in an integrated circuit, comprising: a comparison circuit configured to: compare a monitored voltage to a reference voltage; and output a signal indicating when the monitored voltage is equal to or greater than the reference voltage; and a shunt circuit configured to shunt the current based on receiving the signal from the comparison circuit. ### Claim 2 (depends on 1) The trigger circuit of claim 1, further comprising a first voltage divider circuit coupled to the comparison circuit and configured to: receive an input voltage; divide the input voltage to generate the monitored voltage; and output the monitored voltage to the comparison circuit. ### Claim 3 (depends on 2) The trigger circuit of claim 2, further comprising a second voltage divider circuit coupled to the comparison circuit and configured to: receive the input voltage; divide the input voltage to generate the reference voltage; and output the reference voltage to the comparison circuit. ### Claim 4 (depends on 3) The trigger circuit of claim 3, wherein: the first voltage divider circuit is configured to output the monitored voltage having a first slope of voltage to current; and the second voltage divider circuit is configured to output the reference voltage having a second slope of voltage to current different than the first slope. ### Claim 5 (depends on 1) The trigger circuit of claim 1, further comprising: an inverter circuit coupled to the comparison circuit and configured to invert the output signal and output an inverted output signal to the shunt circuit. ### Claim 6 (depends on 1) The trigger circuit of claim 1, wherein the monitored voltage is generated by a powered or non-powered electrode static discharge (ESD) or electrical overstress (EOS) event. ### Claim 7 (depends on 6) The trigger circuit of claim 6, wherein the reference voltage comprises a floating voltage within a range of a diode drop voltage to a ground voltage for a non-powered event. ### Claim 8 (depends on 6) The trigger circuit of claim 6, wherein the reference voltage is above or below an operating voltage of the integrated circuit for a powered event. ### Claim 9 (depends on 1) The trigger circuit of claim 1, wherein the reference voltage is input by an always ON power supply used to power at least one component of the integrated circuit while the integrated circuit is otherwise powered down. ### Claim 10 (depends on 2) The trigger circuit of claim 2, wherein the first voltage divider circuit is configured to divide the input voltage such that a ratio of the input voltage and the divided input voltage is above an operating voltage of integrated circuit and below a breakdown voltage of the integrated circuit. ### Claim 11 A method for controlling a current shunt in an integrated circuit, comprising: comparing a monitored voltage to a reference voltage; outputting a signal indicating when the monitored voltage is equal to or greater than the reference voltage; and shunting the current based on receiving the signal. ### Claim 12 (depends on 11) The method of claim 11, further comprising: receiving an input voltage; and dividing the input voltage to generate the monitored voltage. ### Claim 13 (depends on 12) The method of claim 12, further comprising: dividing the input voltage to generate the reference voltage. ### Claim 14 (depends on 13) The method of claim 13, wherein: the input voltage is divided to output the monitored voltage having a first slope of voltage to current; and the input voltage is divided to output the reference voltage having a second slope of voltage to current different than the first slope. ### Claim 15 An input device, comprising: a plurality of sensor electrodes; and a processing system coupled to the plurality of sensor electrodes, comprising: sensor circuitry configured to operate the plurality of sensor electrodes for capacitive sensing and determine proximity of an input object based on the capacitive sensing; and trigger circuitry comprising: a comparison circuit configured to compare a monitored voltage to a reference voltage; and output a signal indicating when the monitored voltage is equal to or greater than the reference voltage; and a shunt circuit configured to shunt a current based on receiving the signal from the comparison circuit. ### Claim 16 (depends on 15) The input device of claim 15, wherein the trigger circuitry further comprises a first voltage divider circuit coupled to the comparison circuit and configured to: receive an input voltage; divide the input voltage to generate the monitored voltage; and output the monitored voltage to the comparison circuit. ### Claim 17 (depends on 16) The input device of claim 16, wherein the trigger circuitry further comprises a second voltage divider circuit coupled to the comparison circuit and configured to: receive the input voltage; divide the input voltage to generate the reference voltage; and output the reference voltage to the comparison circuit, wherein: the first voltage divider circuit is configured to output the monitored voltage having a first slope of voltage to current; and the second voltage divider circuit is configured to output the reference voltage having a second slope of voltage to current different than the first slope. ### Claim 18 (depends on 15) The input device of claim 15, wherein the monitored voltage is generated by a powered or non-powered electrode static discharge (ESD) or electrical overstress (EOS) event. ### Claim 19 (depends on 18) The input device of claim 18, wherein the reference voltage comprises a floating voltage within a range of a diode drop voltage to a ground voltage for a non-powered event, and wherein the reference voltage is above or below an operating voltage of the input device for a powered event. ### Claim 20 (depends on 15) The input device of claim 15, wherein the reference voltage is input by an always ON power supply used to power at least one component of the input device while the input device is otherwise powered down.