Capacitive sensing button on chip

Patent metadata

Field	Value
Publication number	US-10969249-B2
Application number	US-201715433932-A
Country	US
Kind code	B2
Filing date	Feb 15, 2017
Priority date	Feb 28, 2011
Publication date	Apr 6, 2021
Grant date	Apr 6, 2021

Abstract

A method, apparatus, and system use logic circuitry arranged within an integrated circuit to: convert a self capacitance of a first sensor element arranged within the integrated circuit to a digital value, and apply a signal to an output pin of the integrated circuit based on the self capacitance.

First claim

What is claimed is:

1. An integrated circuit package comprising:
a first sensor element arranged within the integrated circuit package; and
a controller arranged within the integrated circuit package and coupled to the first sensor element, wherein the controller is configured to:
convert a self capacitance of the first sensor element to a digital value; and
apply a signal to an output pin of the integrated circuit package based on the self capacitance.

2. The integrated circuit package of claim 1 , further comprising a second sensor element arranged within the integrated circuit package and coupled to the controller, wherein the first sensor element is disposed in a first location of the integrated circuit package and the second sensor element is disposed in a second location of the integrated circuit package.

3. The integrated circuit package of claim 2 , wherein the first and second sensor elements are arranged to implement at least one of a linear slider and a scroll wheel.

4. The integrated circuit package of claim 3 , wherein the controller is configured to use digital values to determine a position of a conductive object.

5. The integrated circuit package of claim 2 , wherein the controller is configured to measure the self capacitance of the first and second sensor elements simultaneously.

6. The integrated circuit of claim 1 , wherein the controller is configured to receive a further receive signal from the second sensor element, wherein the further receive signal represents a mutual capacitance between the second sensor element and the first sensor element, wherein the controller is configured to use the digital value and the further receive signal to detect a presence of a conductive object.

7. The integrated circuit package of claim 1 , wherein the controller is configured to detect change in the self capacitance of the first sensor element based on the digital value at a first time and the digital value at a second time.

8. The integrated circuit package of claim 1 , further comprising an output pin coupled to the controller, the output pin configured to carry a signal that is based on the self capacitance of the first sensor element as coupled to a conductive object in proximity to the first sensor element.

9. The integrated circuit package of claim 1 , further comprising a top layer overlying the first sensor element.

10. The integrated circuit package of claim 1 , wherein the controller is formed on a die mounted underneath the first sensor element.

11. The integrated circuit package of claim 1 , further comprising a lead frame coupled to the controller and configured to secure a substrate of the first sensor element.

12. A system comprising:
a device including a user input space; and
a circuit package disposed beneath the user input space, the circuit package comprising:
a first sensor element located within the circuit package; and
a logic circuitry located within the circuit package and coupled to the first sensor element wherein the logic circuitry is configured to:
convert a self capacitance of the first sensor element to a first digital value; and
apply a signal to an output pin of the integrated circuit package based on the self capacitance.

13. The system of claim 12 , wherein the circuit package further comprises a second sensor element located within the circuit package, and wherein the logic circuitry is coupled to the second sensor element and configured to convert a second self capacitance of the second sensor element to a second digital value.

14. The system of claim 13 , wherein the logic circuitry is configured to detect sequential changes in self capacitance of the first and second sensor elements.

15. The system of claim 14 , wherein the first and second sensor elements are arranged to implement at least one of a linear slider and a scroll wheel.

16. The system of claim 12 , wherein the circuit package further comprises an output pin coupled to the logic circuitry, the output pin configured to carry a signal that is based on the self capacitance and is associated with a conductive object proximate to the first sensor element.

17. The system of claim 12 , wherein the circuit package further comprises a lead frame coupled to the logic circuitry and configured to secure a substrate of the first sensor element.

18. A method comprising:
converting a first self capacitance on a first sensor element to a first charge, the first sensor element arranged within an integrated circuit package;
integrating the first charge on a modulation capacitor to generate a modulation voltage;
comparing the modulation voltage on the modulation capacitor to a threshold voltage; and
generating a first digital value representative of the first self capacitance of the first sensor element based an output of the comparing; and
apply a signal to an output pin of the integrated circuit package based on the self capacitance.

19. The method of claim 18 , comprising using the digital value to implement a button function.

20. The method of claim 18 comprising:
converting a second self capacitance on a second sensor element to a second charge, the second sensor element arranged within the integrated circuit package;
integrating the second charge on a modulation capacitor to generate a modulation voltage;
comparing the modulation voltage on the modulation capacitor to a threshold voltage; and
generating a second digital value representative of the second self capacitance of the second sensor element based an output of the comparing.

Assignees

• Cypress Semiconductor Corp
• Cypress Semiconductor Coproration

Inventors

• Narayanasamy Rajagopal
• Swamy Mahadevan Krishnamurthy Narayana
• Wright David G
• Kolokowsky Steve

Classifications

• H03K17/962 Primary

  Capacitive touch switches · CPC title

• H03K2017/9602

  characterised by the type or shape of the sensing electrodes · CPC title

• G01D5/2405 Primary

  by varying dielectric · CPC title

• H03K2217/960755

  Constructional details of capacitive touch and proximity switches · CPC title

• G06F3/0443

  using a single layer of sensing electrodes · CPC title