Estimation of hardened flip-flop neutron soft error rates using SRAM multiple-cell upset data in bulk CMOS

Experimental neutron single-event error rates of 28-and 40-nm bulk CMOS hardened flip-flops are compared to various hardened flip-flop designs in literature. Using published 45-nm SRAM multiple-cell upset data, it is shown that the error rate of hardened flip-flop designs can be estimated by using the minimum sensitive node spacing from the flip-flop layout. Experimental data show that regardless of circuit topology of a hardened flip-flop, the redundant storage node spacing dominates neutron soft-error rates.