In this paper we show that self synchronous circuits can provide robust operation in both soft error prone and low voltage operating environments. Self synchronous circuits are shown to be self checking, where a soft error will either cause a detectable error or halt operation of the circuit. A watchdog circuit is proposed to autonomously detect dual-rail ‘11’ errors and prevent propagation, with measurements in 65nm CMOS showing seamless operation from 1.6V to 0.37V. Compared to a system without the watchdog circuit size and energy-per-operation is increased 6.9% and 16% respectively, while error tolerance to noise is improved 83% and 40% at 1.2V and 0.4V respectively. A circuit that uses the dual-pipeline circuit style as redundancy against permanent faults is also presented and 40nm CMOS measurement results shows correct operation with throughput of 1.2GHz and 810MHz at 1.1V before and after disabling a faulty pipeline stage respectively.