Measuring and correcting non-linearity of an internal multi-bit analog-to-digital converter in a delta-sigma analog-to-digital converter
AssigneeAgilent Technologies, Inc.
InventorBrian Stewart
Life of this patent
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Abstract
An internal ADC in a delta-sigma ADC is characterized using inherent delta-sigma ADC circuitry. In one embodiment, a constant DC value is applied as the input signal. The sum of the constant DC value and a feedback signal is integrated. Then, a digital approximation including the integrated sum is generated. The feedback signal is generated and allows ramping of the integrated sum.
Claims19
A method for testing a circuit that converts an applied analog input signal to a digital representation thereof, comprising:
- (a) applying a constant DC value as the input signal;
- (b) forming a sum of the constant DC value and a feedback signal;
- (c) integrating the sum found in (b);
- (d) generating a first digital approximation including the integrated sum found in (c);
- and
- (e) generating the feedback signal, wherein the feedback signal allows ramping of the integrated sum and a reset of the ramping.
(canceled)
A method for testing a circuit that converts an applied analog input signal to a digital representation thereof, comprising:
- (a) applying a constant DC value as the input signal;
- (b) forming a sum of the constant DC value and a feedback signal;
- (c) integrating the sum found in (b);
- (d) generating a first digital approximation including the integrated sum found in (c);
- (e) generating the feedback signal wherein the feedback signal allows ramping of the integrated sum:
- (f) setting the feedback signal to a fixed value;
- and
- (g) changing the constant DC value to reset the ramping of the integrated sum.
A method for characterizing an internal ADC within a delta-sigma ADC that converts an applied analog input signal to a digital representation thereof, comprising:
- integrating the sum of a constant DC input and a variable value to create a ramp;
- applying the ramp to a first internal ADC having a first input range;
- generating a first digital approximation of the ramp;
- and
- switching the variable value to reset the ramp to one end of the first input range.
Dependencies are inferred from the claim text.