Reference voltage circuitry for use in switched-capacitor applications
AssigneeCirrus Logic, Inc.
InventorsJason Powell Rhode, Vishnu Shankar Srinivasan, Eric Clay Gaalaas, Johann Guy Gaboriau
Life of this patent
Estimating the term…
Abstract
Circuitry for selectively sampling a reference voltage with a capacitor 403 includes a first switch 505a for selectively coupling capacitor 403 to a source of a first reference signal during a first operating phase and a second switch 505b for selectively coupling capacitor 403 to a source of a second reference signal during a second operating phase.
Claims19
Circuitry for sampling a reference voltage with a capacitor comprising:
- a first switch for selectively coupling the capacitor to a voltage supply rail sourcing a first reference signal during a first operating phase;
- and
- a second switch for selectively coupling the capacitor to a second capacitor to generate a second reference signal during a second operating phase, the second reference signal comprising the first reference signal filtered for AC noise.
Circuitry for generating a reference voltage comprising:
- a first switch for sampling a first reference voltage onto a first capacitor during a first operating phase;
- and
- a second switch for coupling charge from a second capacitor to the first capacitor during a second operating phase.
A method for sampling a voltage in switched capacitor circuitry comprising the steps of:
- during a first operating phase, coupling a sampling capacitor to a source of a unfiltered reference voltage;
- and
- during a second operating phase, coupling the sampling capacitor to a source of a filtered reference voltage.
An audio data processing device comprising:
- a data converter including switched-capacitor circuitry, said switched capacitor circuitry comprising:
- a sampling capacitor;
- a first switching circuit for selectively roughly charging said sampling capacitor with a voltage supplied by a voltage supply rail;
- and
- a second switching circuit for selectively finely charging said sampling capacitor, said second switching circuitry coupling said sampling capacitor to a filtering capacitor to filter said voltage supplied by said voltage supply rail for AC noise.
Dependencies are inferred from the claim text.