IP Library Granted Patent US 10,193,338
Granted Patent B2
US 10,193,338 · App. 15/588,309 · Granted Jan 29, 2019

Voltage triggered edge insensitive protection circuit

Inventor: Abhijat Goyal (Lakeway, TX)
Assignee: SYNAPTICS INCORPORATED
H02H9/046G06F3/044H02H9/044G06F2203/04108
View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 10,193,338
App. No.
15/588,309
Granted
Jan 29, 2019
Kind
B2
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 (55)

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, wherein the monitored voltage is generated by a powered or non-powered electrode static discharge (ESD) or electrostatic overstress (EOS) event; 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.

2. 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.

3. 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.

4. 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.

5. 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.

6. 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.

7. The trigger circuit of claim 1 , 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.

8. The trigger circuit of claim 1 , wherein the reference voltage is above or below an operating voltage of the integrated circuit for a powered event.

9. 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.

10. A method for controlling a current shunt in an integrated circuit, comprising:

comparing a monitored voltage to a reference voltage, wherein the monitored voltage is generated by a powered or non-powered electrode static discharge (ESD) or electrostatic overstress (EOS) event;

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.

11. The method of claim 10 , further comprising:

receiving an input voltage; and

dividing the input voltage to generate the monitored voltage.

12. The method of claim 11 , further comprising:

dividing the input voltage to generate the reference voltage.

13. The method of claim 12 , 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.

14. An input device, comprising:

a plurality of sensor electrodes; and

a processing system coupled to the plurality of sensor electrodes

configured to operate the plurality of sensor electrodes for capacitive sensing and determine proximity of an input object based on the capacitive sensing, the processing system comprising

trigger circuitry comprising:

a comparison circuit configured to:

compare a monitored voltage to a reference voltage, wherein the monitored voltage is generated by a powered or non-powered electrode static discharge (ESD) or electrostatic overstress (EOS) event; 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.

15. The input device of claim 14 , 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.

16. The input device of claim 15 , 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.

17. The input device of claim 14 , 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.

18. The input device of claim 14 , 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.

Assignments (3)
CORRECTIVE ASSIGNMENT TO CORRECT THE CORRECT THE SPELLING OF THE ASSIGNOR NAME PREVIOUSLY RECORDED AT REEL: 051316 FRAME: 0777. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNMENT. Recorded Mar 18, 2020
From: SYNAPTICS INCORPORATED
To: WELLS FARGO BANK, NATIONAL ASSOCIATION
Reel/Frame 052186/0756 →
SECURITY INTEREST Recorded Dec 16, 2019
From: SYNAPTICS INCORPROATED
To: WELLS FARGO BANK, NATIONAL ASSOCIATION
Reel/Frame 051316/0777 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 5, 2017
From: GOYAL, ABHIJAT
To: SYNAPTICS INCORPORATED
Reel/Frame 042259/0270 →
Continuity (1)
Related Publication 20180323609A1 · Nov 8, 2018
Cited By (1)
US 12,451,687