System and method for calibrating a time-interleaved digital-to-analog converter

An analog-to-digital conversion system, comprising:

• a main analog-to-digital converter (ADC) configured to convert an analog input signal to a digital signal;
• a digital equalizer configured to remove a distortion incurred by the main ADC from an output of the main ADC;
• an equalizer coefficient estimation block configured to generate coefficients for the digital equalizer;
• a calibration signal generator configured to generate calibration data;
• a time-interleaved digital-to-analog converter (DAC) configured to convert the calibration data to an analog calibration signal, wherein the time-interleaved DAC includes two or more sub-DACs;
• an anti-alias filter configured to filter the analog calibration signal;
• an observation ADC configured to sample, and quantize, the analog calibration signal filtered by the anti-alias filter;
• and
• a mismatch estimation block configured to estimate a frequency response mismatch between the sub-DACs and generate a sub-DAC mismatch correction factor based on an output of the observation ADC,
• wherein the calibration signal generator is configured to apply the sub-DAC mismatch correction factor to the calibration data.

A method for calibrating a time-interleaved digital-to-analog converter (DAC), comprising:

• generating calibration data;
• converting, by a time-interleaved DAC, the calibration data to an analog calibration signal, wherein the time-interleaved DAC includes two or more sub-DACs;
• filtering the analog calibration signal;
• sampling and quantizing, by an observation analog-to-digital converter (ADC), the filtered analog calibration signal;
• estimating a frequency response mismatch between the sub-DACs based on an output of the observation ADC;
• generating a sub-DAC mismatch correction factor based on the estimated frequency response mismatch;
• and
• applying the sub-DAC mismatch correction factor to the calibration data.