Testing of first and second order delta-sigma converters for catastrophic faults

Delta-Sigma analog to digital converters are vital components for mixed-signal systems. So, testing this type of converters is extremely important. This paper studies the low-cost testing of first-order and second-order delta-sigma ADCs. Moreover; only catastrophic faults are considered such as open/short passive components and stuck-at faults in digital components. It is proven that the minimal test set consists of only two values that detect all faults in the assumed fault set. The effect of using different types of counters in the digital subcircuit is investigated and it is found that the two-value test set still detects all faults. Finally, the effect of passive component tolerances is analyzed. All the results are analytically proven and verified by simulations.