Digital Adaptive Calibration of Multi-Step Analog to Digital Converters

This paper reports a novel approach for calibration of multi-step A/D converters based on the steepest-descent estimation method. The calibration procedure is enhanced with dedicated embedded sensors, which register on-chip process parameter and temperature variations. Additionally, to guide the verification process with the information obtained through process monitoring, two efficient algorithms based on an expectation-maximization method and adjusted support vector machine classifier, respectively, are proposed. The algorithms are evaluated on a prototype 12 bits A/D converter fabricated in standard single poly, six metal 90 nm CMOS.