Mismatch compensation techniques using random data for time-interleaved A/D converters

Offset, gain, and sample-time mismatches among different channels of a time-interleaved analog-to-digital converter (ADC) are causes of significant degradation of performance. Compensation techniques for offset mismatch, gain mismatch, and sample-time error in time-interleaved ADCs are proposed. The compensation methods use random digital data and do not use a calibration signal. The offset and gain mismatches are corrected in digital domain, while the timing error correction is performed by adjusting the delay of the clock path of each channel, using a digitally-controlled delay element. The simulation results verify that the proposed compensation techniques estimate and correct offset mismatch, gain mismatch and timing error with a high degree of accuracy. These low complexity techniques are especially suitable for time-interleaved ADCs used in digital data communication systems