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US 7,459,942 B2Granted
Sampled-data circuits using zero crossing detection
AssigneeCambridge Analog Technologies, Inc.
InventorHae-Seung Lee
Life of this patent
Estimating the term…
Abstract
A sampled-data analog circuit includes a level-crossing detector. The level-crossing detector controls sampling switches to provide a precise sample of the output voltage when the level-crossing detector senses the predetermined level crossing of the input signal. The level-crossing detection may be a zero-crossing detection. An optional common-mode feedback circuit can keep the output common-mode voltage substantially constant.
Claims15
A differential switched-capacitor circuit, comprising:
- a level-crossing detector to generate a level-crossing detection signal when a difference between first and second input signals crosses a predetermined level;
- a plurality of capacitors, operatively coupled to said level-crossing detector;
- a sampling switch, operatively coupled to a first output of said level-crossing detector;
- and
- a waveform generator, operatively coupled to said plurality of capacitors and to an input of said level-crossing detector, to produce a predetermined waveform to be applied to the input of said level-crossing detector in response to a second output signal of said level-crossing detector.
2 more elements
A differential switched-capacitor circuit, comprising:
- a first level-crossing detector to generate a level-crossing detection signal when a difference between first and second input signals crosses a first predetermined level;
- a second level-crossing detector to generate a second level-crossing detection signal when a difference between said first and second input signals crosses a second predetermined level;
- a plurality of capacitors, operatively coupled to said first and second level-crossing detectors;
- a sampling switch, operatively coupled to a first output of said second level-crossing detector;
- and
- a waveform generator, operatively coupled to said plurality of capacitors and to an input of said first and second level-crossing detectors, to produce a predetermined waveform to be applied to the input of said first and second level-crossing detectors in response to a second output signal of said first level-crossing detector.
3 more elements
A differential switched capacitor circuit, comprising:
- a first switched capacitance network having an input terminal to receive a circuit input voltage;
- a level-crossing detector, having an output terminal and an input terminal, to generate a level-crossing detection signal when a difference between first and second input signals crosses a predetermined level;
- a second switched capacitance network operatively coupled to a first output of said level-crossing detector;
- and
- a waveform generator, operatively coupled to said second switched capacitance network and to an input of said level-crossing detector, to produce a predetermined waveform to be applied to the input of said level-crossing detector in response to a second output signal of said level-crossing detector.
2 more elements
Dependencies are inferred from the claim text.