Generalized Blind Mismatch Correction for Two-Channel Time-Interleaved A-to-D Converters

Calibration of sub-converter mismatches is a challenging task for high-performance time-interleaved analog-to-digital converters (TIADC). Presently known blind correction methods can remove static gain and sampling time mismatches. However, actual subconverters significantly deviate from a simple gain-timing model, and the resulting modeling error strictly limits maximum output signal-to-noise ratio achievable. Generalized mismatch modeling is, therefore, necessary to break the limitation of gain-timing model. In this paper, we propose a blind method for correcting generalized mismatch errors for M=2 TIADC, which is the first in the literature to the authors´ knowledge. Cyclostationary spectral analysis shows that unique identification is possible in most practical cases. Simulation results show significant performance improvement by the proposed generalized correction method.