Wilfried Tenten

Hierarchical fault diagnosis of analog integrated circuits

This paper introduces a hierarchical-fault-diagnosis algorithm as an aid to testing analog and mixed signal circuits. The diagnosis approach is based on that introduced by Wey and others and makes use of the self-test algorithm, and the component-connection model. The main extension to these techniques is the use of a hierarchical approach whereby blocks of circuitry are grouped together leading to a reduction in matrix size, so making even large scale circuits diagnosable. Other improvements from this approach include a novel test-point selection procedure and the fact that hard faults can also be diagnosed, provided they lie completely within a hierarchical block. The overall algorithm is described and the results from example circuits show good functionality of the diagnosis algorithm. Fault masking and sensitivity to the simulation/measurement resolution of test point values are examined and are highlighted as future activities to further improve the approach.

Novel analog to digital converters using voltage inverter switches. I. Reference circuits

Novel analog to digital converter (ADC) circuits that incorporate voltage inverter switches (VISs) are described. In the first part the principles of voltage inversion are described. It is shown how these circuits can be used to construct very accurate divide-by-two reference circuits. Due to the ability of the VIS circuits to compensate for parasitic losses during the process of capacitor charge redistribution, these reference circuits are superior to previous designs. Three different VIS reference circuits are presented. Theoretical analyses are confirmed with computer simulations and measured results from experimental circuits. >