×

Capacitive field sensor with sigma-delta modulator

  • US 8,564,313 B1
  • Filed: 09/12/2012
  • Issued: 10/22/2013
  • Est. Priority Date: 07/03/2007
  • Status: Active Grant
First Claim
Patent Images

1. A method comprising:

  • generating a pulse signal based on a pseudorandom signal;

    responsive to a first level of the pulse signal, charging a sensing capacitor and a modulation capacitor;

    responsive to a second level of the pulse signal, discharging the sensing capacitor;

    generating a modulating signal based on an amount of charge stored on the modulation capacitor; and

    determining, based on a duty cycle of the modulating signal, whether an object is proximate to the sensing capacitor.

View all claims
  • 6 Assignments
Timeline View
Assignment View
    ×
    ×