Utilization of Noise-Shaping in Mixed-Signal Timing-Skew Mismatch Calibration of TI-ADCs

This paper proposes an approach based on oversampling and noise-shaping mechanisms to mitigate the implementation complexity of variable delay lines for mixed-signal calibration of timing-skew mismatch in time-interleaving ADCs. The proposed technique pushes the error (introduced by increasing the delay steps) outside the operating frequencies. Our method is more appropriate for noise-shaping time-interleaved ADCs since they are band-limited. However, the proposed method permits the utilization of either the high-frequency or low-frequency zones. This approach avoids utilizing complex clock routing methods. Also, it does not restrict the number of sub-ADCs. The proposed method is verified by behavioral simulations with MATLAB/Simulink. The mean of the spurious-free dynamic range (SFDR) is respectively enhanced by 11.64 dB and 17.72 dB for the low-frequency and high-frequency zones.