Evaluating the Effectiveness of a Mixed-Signal TMR Scheme Based on Design Diversity

This paper explores the concept of design diversity redundancy applied to mixed-signal (MS) circuit blocks, as a proposal to increase system reliability. Three different implementations of a second order low-pass filter (which perform the same transfer function) associated to a majority voter are used to build a diversity TMR scheme. The whole system is prototyped by using a single programmable mixed-signal device. Functional verifications and a fault injection campaign are performed, and the effectiveness of the voting system to detect single faults is investigated. Based on these results, analytical calculations were done to estimate the behavior of the system under the occurrence of double faults. Results show a very good ability of the system to tolerate double faults from the considered model.