A new fully digital frequency response mismatch compensation algorithm for time interleaved analog-to-digital converters

Abstract

This paper proposes a new efficient fully digital adaptive method for arbitrary frequency-response mismatches of time-interleaved analog-to-digital converters. It uses FIR filters for signal correction. Correlations between TIADC output data and two different frequency shifted images of these data are used for mismatch estimation. This method has been evaluated in the case of 4-channel TIADCs but it can be extended to any number of channels.. Hardware implementation of this new algorithm was carried out and successfully tested at a 2.56 GHz sampling rate on both single tone and dual tone signals. Efficient spur cancellation (30 dB typically) using 3-tap filters for single tone signals and 7-tap filters for dual tone signals has been demonstrated.