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US 6,232,899 B1Granted
Analogue and digital convertors
AssigneeCirrus Logic, Inc.
InventorPeter Graham Craven
Life of this patent
Estimating the term…
Abstract
A signal convertor comprising a pulse modulator, and means for modifying the signal input thereto in dependence upon the error in previous values of the output thereof, to reduce the effects of said error within a desired signal band.
Claims25
A signal convertor comprising:
- a pulse edge modulator having an input and providing an output, and a feedback circuit for modifying said input to said pulse edge modulator in response to any error in previous values of said modulator output, thereby reducing effects of said any error within at least a desired signal band.
A signal converter comprising:
- a pulse edge modulator controlled by an output of a quantizer, the quantizer having a processed input, said input processed in dependence upon said quantizer output, by a non-linear stage for reducing effects of any non-linearity due to the pulse edge modulator over at least one signal frequency band.
A signal converter comprising:
- a signal input;
- a quantizer;
- a feedback network around said quantizer for reducing quantizer noise in at least a desired frequency band relative to a spectrum of said quantizer which would be exhibited without said feedback network;
- and
- a pulse modulator, responsive to an output of said quantizer, for providing an output of predetermined amplitude pulses, wherein times of occurrence of edges of said pulses are controlled in order to reduce the noise due to the pulse edge modulator within at least a desired signal frequency band.
2 more elements
A signal convertor including:
- a pulse edge modulator;
- and
- a digital memory for storing data related to distortion present in an output of said modulator in response to varying input signal levels.
A signal convertor which includes:
- a pulse modulator producing pulses having edges, temporal positions of said edges being controlled in dependence upon a value of a digital input to the converter;
- and
- a look-up table storing a plurality of correction values, said look-up table being addressed in dependence upon a digital input, and digital delay elements differentially delaying said digital input, said look-up table output being combined with each digital input to the convertor to reduce any error generated by the pulse modulator in response to said digital input.
A signal convertor which includes:
- a pulse modulator producing pulses having edges, temporal positions of said edges being controlled in dependence upon a value of a digital input to the converter;
- and
- a look-up table storing a plurality of correction values, said look-up table being addressed in dependence upon a digital input and having multiple outputs, and digital delay elements differentially delaying said multiple outputs of said look up-table, said delayed look-up table outputs being combined with each digital input to the convertor to reduce any error generated by the pulse modulator in response to said digital input.
A signal convertor which includes:
- a pulse modulator producing pulses having edges, temporal positions of said edges being controlled in dependence upon a value of a digital input to the converter;
- a look-up table storing a plurality of correction values, said look-up table being addressed in dependence upon a digital input;
- and
- digital delay elements for differentially delaying said digital input, said look-up table output being connected to said pulse modulator to reduce any error generated by the pulse modulator in response to said digital input.
1 more element
A signal convertor which includes:
- a pulse modulator producing pulses having edges, temporal positions of said edges being controlled in dependence upon a value of a digital input to the converter;
- a look-up table storing a plurality of correction values, said look-up table being addressed in dependence upon a digital input and having multiple outputs;
- and
- digital delay elements for differentially delaying said multiple outputs of said look-up table, said look-up table outputs being connected to said pulse modulator to reduce any error generated by the pulse modulator in response to said digital input.
1 more element
A signal convertor having an input receiving a digital signal sampled with a sampling period, the convertor comprising:
- a pulse modulator controlled by an output of a quantizer, the quantizer having a processed input, said input being processed in dependence upon said quantizer output, by a feedback circuit incorporating at least one non-linear element.
Dependencies are inferred from the claim text.