DEVICE AND METHOD FOR GENERATING AN ELECTRICAL POWER SUPPLY IN AN ELECTRONIC SYSTEM WITH A VARIABLE REFERENCE POTENTIAL

• US 20170220156A1
• Filed: 04/17/2017
• Published: 08/03/2017
• Est. Priority Date: 06/16/2011
• Status: Active Grant

• Current Assignee: Quickstep Technologies, LLC (Broadcom, Inc.)
• Original Assignee: Quickstep Technologies, LLC (Broadcom, Inc.)
• Inventors: BLONDIN, Christophe, NEEL, Christian, ROZIERE, Didier
• Granted Patent: US 10,503,328 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: H02J 1/08 Three-wire systems; Systems having more than three wires
• CPC Class Codes: H02M 7/02 Conversion of ac power input into dc power output without possibility of reversal
• CPC Class Codes: H02M 7/06 using discharge tubes without control electrode or semiconductor devices without control electrode
• CPC Class Codes: H03K 17/9622 using a plurality of detectors, e.g. keyboard
• CPC Class Codes: H03K 2217/9607 Capacitive touch switches
• CPC Class Codes: H03K 2217/960745 Capacitive differential; e.g. comparison with reference capacitance

Abstract

A method and device for generating a power supply voltage, referenced to a first reference potential, in an electronic system including an energizing source connected to the first and second reference potentials so as to impart an AC voltage differential between the reference potentials, wherein the device includes: (i) a source for supplying AC voltage, which is referenced to the second reference potential, connected to the first reference potential, and encompasses the energizing source; and (ii) rectifying and filtering elements connected, at the input thereof, to the first reference potential and to the source for supplying AC voltage, respectively, so as to generate, at an output, a power supply voltage (Vf) referenced to the first reference potential by rectifying a voltage at the terminals of the source for supplying AC voltage.

Claims

1. An apparatus for touch and proximity detection, comprising:

a first electronic measurement system referenced to a first potential;

a second electronic measurement system communicatively coupled to the first electronic measurement system and referenced to a second potential;

wherein the first potential is selected in accordance with a reference potential of an object to be detected; and

wherein the first potential and the second potential maintain an AC voltage difference between them.

2. The apparatus of claim 1, further comprising an AC voltage supply source referenced to the first potential and configured for generating and providing the second potential and a power supply voltage (Vf) referenced to the second potential to the second electronic measurement system.

3. The apparatus of claim 2, further comprising a voltage rectification and filtering circuit coupled between the AC voltage supply source and the second electronic measurement system for generating the power supply voltage (Vf).

4. The apparatus of claim 2, the AC voltage supply source further comprising a first excitation source for generating the AC voltage difference between the first potential and the second potential.

5. The apparatus of claim 1, further comprising decoupling capacitors coupled between the first electronic measurement system and the second electronic measurement system.

6. The apparatus of claim 2, the AC voltage supply source further comprising a second excitation source for generating the power supply voltage.

7. The apparatus of claim 1, the second electronic measurement system comprising one or more electrodes referenced to the second potential.

8. The apparatus of claim 7, the second electronic measurement system comprising one or more guard electrodes placed in proximity to the one or more electrodes and referenced to the second potential.

9. The apparatus of claim 1, wherein the apparatus is incorporated into a portable computing device.

17. The method of claim 6, further comprising placing one or more guard electrodes in proximity to the one or more electrodes and referencing the one or more guard electrodes to the second potential.

10. A method for touch and proximity detection, comprising:

referencing a first electronic measurement system to a first potential;

referencing a second electronic measurement system to a second potential and communicatively coupling the second electronic measurement system to the first electronic measurement system;

selecting the first potential in accordance with a reference potential of an object to be detected; and

maintaining an AC voltage difference between the first potential and the second potential.

11. The method of claim 10, further comprising generating and providing the second potential and a power supply voltage (Vf) referenced to the second potential to the second electronic measurement system using an AC voltage supply source referenced to the first potential.

12. The method of claim 11, further comprising voltage rectifying and filtering an output of the AC voltage supply source to generate the power supply voltage (Vf).

13. The method of claim 11, further comprising generating the AC voltage difference between the first potential and the second potential using a first excitation source.

14. The method of claim 10, further comprising decoupling electrical connections between the first electronic measurement system and the second electronic measurement system.

15. The method of claim 11, further comprising generating the power supply voltage using a second excitation source.

16. The method of claim 10, further comprising performing touch and proximity detection using one or more electrodes referenced to the second potential.

18. An apparatus for touch and proximity detection, comprising:

means for referencing a first electronic measurement system to a first potential;

means for referencing a second electronic measurement system to a second potential and communicatively coupling the second electronic measurement system to the first electronic measurement system;

means for selecting the first potential in accordance with a reference potential of an object to be detected; and

means for maintaining an AC voltage difference between the first potential and the second potential.

19. The apparatus of claim 18, further comprising means for generating and providing the second potential and a power supply voltage (Vf) referenced to the second potential to the second electronic measurement system using an AC voltage supply source referenced to the first potential.

20. The apparatus of claim 19, further comprising means for voltage rectifying and filtering an output of the AC voltage supply source to generate the power supply voltage (Vf).