A digital calibration technique for folding-integration/cyclic cascaded ADCs

Abstract

A digital calibration technique for folding-integration/cyclic cascaded (FICC) analog-to-digital converters (ADCs) is proposed in this paper. The calibration is done by compensating non-ideal errors in digital domain. The errors generated during each converting cycle and the final effects of them are calculated with properly established model in charge domain according to the behaviors of the FICC ADC. The simulation results show that the maximum integral nonlinearity (INL) is improved from +60.9/-36.8 LSB to +0.89/-0.95 LSB, and the differential nonlinearity (DNL) is improved from +71.5/-2.0 LSB to +0.64/-0.62 LSB for 18-bit resolution. Both high-resolution and high-linearity are simultaneously achieved in the FICC ADC by employing the proposed digital calibration technique.