US 10,897,261 B1 · Analog-to-digital converter with a supplementary digital-to-analog converter for offset and gain error measurements

Abstract

A switched-capacitor analog-to-digital converter (ADC) includes: a main digital-to-analog converter (DAC) circuit; a comparator coupled to the main DAC circuit and configured to determine whether the input to the comparator exceeds a pre-determined threshold; and a supplementary DAC circuit coupled to the main DAC circuit, wherein the switched-capacitor ADC is configured to operate in at least one of a first mode or a second mode, wherein in the first mode for measuring an offset of the switched-capacitor ADC, the supplementary DAC circuit is configured to shift a voltage at an output of the main DAC circuit by a first value having a first polarity, and wherein in the second mode for measuring a full-scale gain error of the switched-capacitor ADC, the supplementary DAC circuit is configured to shift the voltage at the output of the main DAC circuit by a second value having a second polarity opposite the first polarity.

Claims20

Dependent claims

A switched-capacitor analog-to-digital converter (ADC) comprising:

a main digital-to-analog converter (DAC) circuit having an output;
a comparator having an input coupled to the output of the main DAC circuit, the comparator configured to determine whether the input to the comparator exceeds a pre-determined threshold;
and
a supplementary DAC circuit coupled to the main DAC circuit,
wherein the switched-capacitor ADC is configured to operate in at least one of a first mode or a second mode, wherein in the first mode for measuring an offset of the switched-capacitor ADC with a zero voltage input, the supplementary DAC circuit is configured to shift a voltage at the output of the main DAC circuit by a first value having a first polarity, and wherein in the second mode for measuring a full-scale gain error of the switched-capacitor ADC with a full-scale input voltage, the supplementary DAC circuit is configured to shift the voltage at the output of the main DAC circuit by a second value having a second polarity opposite the first polarity.

2 more elements

A switched-capacitor analog-to-digital converter (ADC) comprising:

a main digital-to-analog converter (DAC) circuit having an output;
a comparator coupled to the output of the main DAC circuit;
and
a supplementary DAC circuit comprising:
at least one supplementary capacitor, wherein a first terminal of the at least one supplementary capacitor is coupled to the output of the main DAC circuit;
a first switch coupled between a second terminal of the at least one supplementary capacitor and a first reference voltage terminal of the switched-capacitor ADC;
and
a second switch coupled between the second terminal of the at least one supplementary capacitor and a second reference voltage terminal of the switched-capacitor ADC.

5 more elements

A method of operating a switched-capacitor analog-to-digital converter (ADC), the method comprising at least one of:

shifting a DC transfer curve of the switched-capacitor ADC in a first direction by a pre-determined value during measurement of an offset of the switched-capacitor ADC with a zero-voltage input;
and
shifting the DC transfer curve of the switched-capacitor ADC in a second direction opposite the first direction by the pre-determined value during measurement of a full-scale gain error of the switched-capacitor ADC with a full-scale voltage input.

Dependencies are inferred from the claim text.

Analog-to-digital converter with a supplementary digital-to-analog converter for offset and gain error measurements

Life of this patent

Analog-to-digital converter with a supplementary digital-to-analog converter for offset and gain error measurements

Life of this patent

Abstract

Claims20