The reliability of ADCs used in highly critical systems can be increased by applying a two-step procedure starting with sensitivity analysis followed by redesign. The sensitivity analysis is used to identify the most sensitive blocks which could then be redesigned for better reliability by incorporating fault tolerance. This paper illustrates the steps involved in incorporating fault tolerance in an ADC. Two redesign techniques to improve the reliability of a circuit are presented. Novel selective node resizing algorithms for increased tolerance against α-particle induced transients are discussed.