'Skip-Swap' method instead of 'Skip-Fill' method in background calibration of pipelined ADCs

摘要

This paper presents a new background calibration technique employing an extra slow but accurate ADC for correcting the linear and nonlinear gain errors in pipelined ADCs. In comparison to the well-known skip-fill method, the proposed skip-swap algorithm enables the calibration of the pipelined ADC with low power consumption and fast convergence, while usable in Nyquist frequencies with low SNDR degradation. The simulation results for a behaviorally modeled 12-bit 200MS/s 1.5bit/stage pipelined ADC show the improvement of DNL and INL from 88.2 and 209 LSB to 0.89 and 1.06 LSB, respectively. The ADC achieves a SNDR of 72.5 dB after calibration.