Redundant comparator design for improved offset voltage and single event effects hardness

Abstract

An analog comparator architecture has improved immunity to single event effects and variations in input offset voltage. A conventional single analog comparator-based circuit is replaced with plural comparators, driving a “majority vote” logic block. The effective input offset voltage of the multi-comparator design is the middle one of the individual comparators' input offset voltages. A single event upset on any comparator may momentarily perturb its output into the incorrect state; however, the output of the majority voting logic block will remain in the correct state, as only one comparator is upset. In addition, where a heavy ion strike on any comparator's bias current source causes a momentary loss of bias current, this upsets only one comparator, so that the output of the voting logic block is unaffected.