Reliable digital circuits design using sigma-delta modulated signals

As the transistor gate length goes straightforward to the sub-micron dimension, the possibilities of occurrence of external interferences in these devices also increase. Moreover, the process variability further degrade this scenario. The direct effect of such external and/or intrinsic interferences is, in many cases, the total mismatch between the desired answer of the system and the achieved answer resulting from single bit flips. This way, new techniques must be studied in order to guarantee the correct operation of these systems. This work presents the use of a totally digital sigma-delta modulator that is used to develop arithmetic operations, which are further used to develop a FIR filter. Simulations results show that, even with the insertion of a large amount of faults, one can still obtain a nonfaulty behavior in the SNR of complex application.