Device and method for generating an electrical power supply in an electronic system with a variable reference potential

• US 9,640,991 B2
• Filed: 06/08/2012
• Issued: 05/02/2017
• 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
• Primary Examiner(s): Deberadinis, Robert
• Application Number:
  US14/126,163
• Publication Number:
  US 20140103712A1
• Time in Patent Office: 1,789 Days
• Field of Search: 307412
• 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 (Vf), referenced to a first reference potential (4), in an electronic system including an energizing source (3) connected to the first and second reference potentials (4, 5) so as to impart an AC voltage differential between the reference potentials (4, 5), wherein the device includes: (i) a source (10) for supplying AC voltage, which is referenced to the second reference potential (5), connected to the first reference potential (4), and encompasses the energizing source (3); and (ii) rectifying and filtering elements (1) connected, at the input thereof, to the first reference potential (4) and to the source (10) for supplying AC voltage, respectively, so as to generate, at an output (8), a power supply voltage (Vf) referenced to the first reference potential (4) by rectifying a voltage at the terminals of the source (10) for supplying AC voltage.

Claims

1. Device for generating a power supply voltage (Vf) referenced to a first reference potential, in an electronic system comprising a first excitation source configured for generating said first reference potential and referenced to a second reference potential so as to impose an alternating current (AC) voltage difference between these reference potentials, the device comprising:

an AC voltage supply source referenced to said second reference potential, generating said first reference potential, and encompassing said first excitation source, and

rectifying and filtering means connected to said first reference potential and to said AC voltage supply source to generate, at an output, the power supply voltage (Vf) referenced to said first reference potential by rectification of a voltage at terminals of the AC voltage supply source.

2. Device according to claim 1, wherein the first excitation source is referenced to the second reference potential.

3. Device according to claim 2, the first excitation source comprising a buffer referenced to the second reference potential, connected at its output to the first reference potential, and controlled at its input by an oscillator referenced to said first reference potential.

4. Device according to claim 1, the rectifying and filtering means connected to the first excitation source.

5. Device according to claim 1, the AC voltage supply source comprising at least one second excitation source connected to the second reference potential, the rectifying and filtering means connected to said second excitation source.

6. Device according to claim 5, wherein an output of the second excitation source is referenced to the first reference potential.

7. Device according to claim 1, wherein the rectifying and filtering means comprise switching means.

8. Device according to claim 1, wherein the rectifying and filtering means comprise at least one diode inserted between the AC voltage supply source and the power supply voltage (Vf).

9. Device according to claim 1, wherein the rectifying and filtering means comprise at least one diode having a low threshold.

10. Device according to claim 1, wherein the rectifying and filtering means comprise a filtering capacitor connected to the first reference potential and to the power supply voltage (Vf).

11. Device according to claim 1, produced using integrated electronics technologies.

12. Electronic capacitive measurement system comprising a first sub-system electrically referenced to the first reference potential, a second sub-system electrically referenced to the second reference potential,

the electronic capacitive measurement system further comprising the device according to claim 1.

13. Electronic capacitive measurement system according to claim 12, further comprising a charge amplifier referenced to the first reference potential and supplied by the device for generating the supply voltage (Vf) referenced to said first reference potential.

14. Method for generating a supply voltage (Vf) referenced to a first reference potential in an electronic system comprising an excitation source configured for generating said first reference potential and referenced to a second reference potential so as to impose an alternating current (AC) voltage difference between these reference potentials, the method comprising:

generating an AC supply voltage by means of an AC voltage supply source referenced to said second reference potential to generate said first reference potential, the AC voltage supply source encompassing said excitation source, and

rectifying and filtering a voltage at terminals of said AC voltage supply source to generate the supply voltage (Vf) referenced to said first reference potential.