On external calibration of analog-to-digital converters

External calibration and compensation of analog-to-digital converters is considered. Two novel methods are presented. Both methods employ multiple calibration frequencies in order to improve the wide-band performance of the converter. Also, a dynamic table indexing is introduced to further improve the performance. A recursive sine-wave reconstruction filter algorithm is developed for calibration purposes. The proposed methods are evaluated using experimental converter data. Results indicate that the dynamic indexing provides good correction performance, also at frequencies not used during calibration. Thus, wide-band calibration can be achieved