Low power consumption and radiation hardness are generally com-peting requirements for space electronics as well as many earth-bound high reliability applications. Recently, subthreshold logic has emerged as a technology that can deliver the theoretical minimum energy per computation by running at ultra-low levels. The resulting performance degradation is tolerable due the dramatic increase in energy efficiency. However, operating circuits at such low voltages decreases the critical charge - Qcrit - required to corrupt the contents of memories and sequential elements. The marriage of...