Blind calibration of timing skew in time-interleaved analog-to-digital converters

Abstract

The performance of time-interleaved analog-to-digital converters is often significantly degraded by timing mismatch errors. We develop methods for performing blind calibration of such converters, i.e., for estimating the unknown time-skew parameters and for performing signal reconstruction from these estimates. The methods are low in complexity and allow for accurate calibration in systems with large numbers of converters, provided that the skews are sufficiently small in magnitude. We also present modifications to calibrate gain mismatch as well as adaptive sequential methods of implementation. Performance and complexity analysis is provided to support the viability of the methods.