Sigma-delta converter system and method
AssigneeIntersil Americas Inc.
InventorsGiri NK RANGAN, Roger LEVINSON, John M. CARUSO
Life of this patent
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Abstract
A sigma-delta converter may include a filter coupled to a first summation circuit and a second summation circuit. A multi bit quantizer may be coupled to the second summation circuit. A single bit digital-to-analog converter (DAC) may be included that defines a feedback path between the multi-bit quantizer and the first summation circuit. A feed-forward coefficient circuit defining a feed forward path between the first summation circuit and the second summation circuit may be included.
Claims18
A method of controlling a feed forward sigma-delta converter including a multi bit quantizer and having a feed forward coefficient, comprising:
- varying the value of the feed forward coefficient, which is multiplied by an input signal supplied to the sigma-delta converter, as a function of a gain control signal that is generated responsive to an output of the multi bit quantizer.
A method of controlling a feed forward sigma-delta converter, comprising:
- receiving an input voltage;
- filtering the input voltage to generate a filtered output signal;
- quantizing the filtered output signal to generate a multiple bit digital output;
- adjusting the value of a feed forward coefficient responsive to the multiple bit digital output;
- and
- multiplying the input voltage times the feed forward coefficient and supplying the value of the input voltage times the feed forward coefficient to change the value of the filtered output signal.
A sigma-delta converter, comprising:
- a filter coupled to a first summation circuit at an input, and a second summation circuit at an output;
- a multi bit quantizer coupled to the second summation circuit;
- a single bit digital-to-analog converter (DAC) defining a feedback path between the multi bit quantizer and the first summation circuit;
- and
- a feed-forward coefficient circuit coupled between the first summation circuit and the second summation circuit, the feed-forward coefficient circuit comprising:
- switched capacitor circuitry having an input node configured to receive an input voltage and having an output;
- an operational amplifier having first and second inputs and having an output, the output of the switched capacitor circuit being coupled to a selected one of the first and second inputs;
- and
- a feedback network coupled to the selected one of the first and second inputs of the operational amplifier and to the output of the operational amplifier.
Dependencies are inferred from the claim text.