First Order Statistic Based Fast Blind Calibration of Time Skews for Time-Interleaved ADCs

A full digital background method is proposed in this brief for timing mismatch calibrations of time-interleaved analog-to-digital converters (TIADCs) with wide sense stationary input signals. First, errors caused by timing mismatches are modeled as additive errors by applying the Taylor series approximation. Then, a mismatch estimation approach based on first-order statistics is proposed. In addition, computations are simplified significantly by using some valuable properties of the signals in TIADC channels. Further, a variable step-size iterative technique is presented to reduce steady-state errors. So the mismatch estimates are guaranteed to converge to actual values within three steps iterations. Theoretical analyses and experiments show that the proposed method has the advantages of low complexity and fast convergence over most other conventional methods. The proposed method is feasible for fast on-line timing mismatch calibrations of TIADCs.