Digital estimation and calibration algorithm for 2-order nonlinearity mismatch in time-interleaved sampling system

Channel mismatches in time-interleaved sampling system would result in a significant decline in dynamic performance. Nonlinearity mismatch, as one kind of the channel mismatches, has not been widely investigated. In this paper, we present and evaluate the digital estimation and compensation method for the 2-order nonlinearity mismatch in an M-channel time-interleaved analog-to-digital converters (TIADC). Simulation results demonstrate that the foreground estimation method can perform fine accuracy. By employing adders and multipliers, the digital calibration method can bring a great improvement in the dynamic performance of TIADC.