Analog circuit differential pair element mismatch detection using spectral separation

An apparatus, comprising:

• an analog circuit having a plurality of differential pairs of elements, wherein for each pair of the plurality of differential pairs of elements, the elements of the pair are designed to match but may have mismatch that induces error;
• an analog-to-digital converter (ADC) configured to monitor an output of the analog circuit;
• and
• a controller configured to, for each pair of at least two pairs of the plurality of differential pairs of elements:
• spectrally separate the mismatch-induced error of the pair from mismatch-induced error of a remainder of the plurality of differential pairs of elements;
• and
• analyze the monitored output to measure the mismatch-induced error of the pair.

A method for use in an analog circuit having at least one differential pair of elements, wherein for each pair of the at least one differential pair of elements, the elements of the pair are designed to match but may have mismatch that induces error, comprising:

• measuring, using an analog-to-digital converter (ADC), a first value of the mismatch of the pair at a first chopping frequency;
• measuring, using the ADC, a second value of the mismatch of the pair at a second chopping frequency distinct from the first chopping frequency;
• and
• measuring a chopping-induced error based on a difference between the first and second values of the mismatch of the pair.