On automatic fault isolation using DFT methodology for active analog filters

DFT methodology for active analog filters based on analog scan structures has been proposed previously. The authors describe an extension of the methodology to automatic fault isolation by means of model-based diagnosis performed by the AI tool CLP. The implemented diagnostic algorithm uses results of measurements of magnitude and phase characteristics for a given frequency in the normal mode and in the test modes. The diagnosis is performed incrementally, in each step reducing the set of potential candidates for the detected fault. Presented case study illustrates the approach.