Low cost automatic test vector generation for structural analog testing

This work presents a low cost automatic method to test vector generation for defect-oriented structural analog testing. An optimal set of analog single tone signals is obtained by computing the frequency response of circuit nodes, while iteratively injecting faults, using a SPICE simulator. The method also allows to identify the nodes of the circuit with higher observabilities to the injected faults, by comparing the obtained fault coverage as a function of frequency. A 130 nm ΣΔ modulator is used as case study to validate the technique under fault injection campaigns. Up to 100% fault coverage is obtained depending on the number of test points. A trade-off is identified, in such a way that a single test point may be used, achieving 95% of fault coverage. The optimized sets of single tone signals can be either combined in a multi-tone testing strategy or sequentially applied during the test application phase.