Time Skew Calibration for Time-Interleaved Analog-to-Digital Converters

Abstract

This paper presents an all-digital extraction method for time skew in the time interleaved analog-to-digital converters. Firstly, the fractional delay filter is used to construct the reference of extraction time skew. Secondly, a time-varying step and sign-sign gradient descent least mean squares algorithm is applied to extract time skew. Thirdly, an appropriate window function is designed to make the bandwidth of fractional delay filter larger. Finally, time-varying steps and iterations-varying samples reduce the power consumption of estimation in the LMS algorithm. The advantage of the proposed technique is that it doesn't require additional hardware reference and has low power consumption, fast convergence rate, strong portability.