Analog-to-digital converter system and method
AssigneeLinear Technology Corporation
InventorJesper STEENSGAARD-MADSEN
Life of this patent
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Abstract
An analog-to-digital converter (ADC) system and method. The ADC system in accord with one embodiment includes a sampling digital-to-analog converter configured to sample a combination of an analog signal value and an analog dither value, and a control circuit comprising a mismatch-shaping encoder. The control circuit is configured to sequentially apply a plurality of digital codes to the sampling digital-to-analog converter during an analog-to-digital conversion operation to derive a digital code representing the combination of the analog signal value and the analog dither value. Several embodiments are presented.
Claims112
An analog-to-digital converter system comprising:
- a sampling digital-to-analog converter configured to sample a combination of an analog signal value and an analog dither value;
- a control circuit comprising a mismatch-shaping encoder , the control circuit configured to sequentially apply a plurality of digital codes to the sampling digital-to-analog converter during an analog-to-digital conversion operation to derive a digital code representing the combination of the analog signal value and the analog dither value.
An analog-to-digital converter system comprising:
- a sampling digital-to-analog converter configured to provide a sampled representation of a first analog value comprising a portion of an analog signal value and a portion of an analog dither value;
- a dither generator circuit configured to apply a digital dither code to the sampling digital-to-analog converter at a sampling instance;
- and
- a control circuit configured to derive a first digital code to represent the first analog value;
- the control circuit further configured to combine the first digital code and the digital dither code to derive an encoded numerical representation of the analog signal value;
- wherein the dither generator circuit is configured to be responsive to a preceding digital code derived during a preceding analog-to-digital conversion operation to represent an analog value.
An analog-to-digital converter operating in a sampling phase and a conversion phase, comprising:
- a sampling digital-to-analog converter having a first plurality of input terminals and a second plurality of input terminals;
- a control circuit comprising a mismatch-shaping encoder;
- in the sampling phase, the control circuit configured to couple an analog input signal to at least one terminal in the first plurality of input terminals and to apply a digital dither code to the second plurality of input terminals;
- in the conversion phase, the control circuit configured to sequentially apply a plurality of digital codes to the sampling digital-to-analog converter to derive an encoded numerical representation of a value of the analog input signal at a sampling instance.
An analog-to-digital converter system comprising:
- a sampling digital-to-analog converter configured to sample an analog value and to provide a representation of a residue of the sampled analog value with respect to a digital code;
- a plurality of registers configured to store codes representing weighting factors of the sampling digital-to-analog converter measured to account for variations in a manufacturing process;
- a control circuit comprising a mismatch-shaping encoder;
- the control circuit configured to derive and apply a first digital code to the sampling digital-to-analog converter during an analog-to-digital conversion operation;
- and
- a digital circuit configured to combine bit values of the first digital code with codes stored in the plurality of registers to derive a digital output code representing an analog signal value.
An analog-to-digital converter system comprising:
- a capacitive digital-to-analog converter configured to sample a combination of an analog signal value and an analog dither value;
- a control circuit comprising a scrambler circuit for scrambling bit values of digital codes applied to the capacitive digital-to-analog converter;
- the control circuit configured to sequentially apply a plurality of digital codes to the capacitive digital-to-analog converter during an analog-to-digital conversion operation to derive an encoded numerical representation of the analog signal value.
An analog-to-digital converter system comprising:
- a capacitive digital-to-analog converter configured to substantially isolate a first analog value comprising a portion of an analog signal value and a portion of an analog dither value;
- a dither generator circuit configured to apply a digital dither code to the capacitive digital-to-analog converter during an acquisition period;
- a control circuit configured to derive a first digital code to represent the first analog value;
- the control circuit further configured to combine the first digital code and the digital dither code to derive an encoded numerical representation of the analog signal value;
- wherein the dither generator circuit is configured to be responsive to a preceding digital code derived during a preceding analog-to-digital conversion operation to represent an analog value.
A method for deriving an encoded numerical representation of an analog signal value using a sampling digital-to-analog converter having a plurality of input terminals, comprising the steps of:
- isolating a first charge portion on a sampling node of the sampling digital-to-analog converter while applying a first digital dither code to at least one input terminal in the plurality of input terminals;
- applying a first digital code to the sampling digital-to-analog converter for which a potential of the sampling node is within a predefined range;
- generating a second digital dither code responsive to the first digital code;
- combining the first digital dither code and the first digital code to derive the encoded numerical representation of the analog signal value.
Dependencies are inferred from the claim text.