Design-for-Test method for high-speed ADCs: Behavioral description and optimization

This paper presents a Design-for-Test (DfT) approach for folded analog to digital converters. A sensor circuit is designed to sample several internal ADC test points at the same time, so that, by computing the relative deviation among them the presence of a defect can be detected. A fault evaluation is carried out on a behavioral model to compare the coverage of the proposed test approach with the one obtained from a functional test. Then, the analysis is moved to a transistor level implementation of the ADC to establish the threshold limits for the DfT circuit that maximize the fault coverage figure of the test approach.