A fast, analytical estimator for the SEU-induced pulse width in combinational designs

Single event upsets (SEUs) are becoming increasingly problematic for both combinational and sequential circuits with device scaling, lower supply voltages and higher operating frequencies. To design radiation tolerant circuits efficiently, techniques are required to analyze the effects of a particle strike on a circuit early in the design flow and also to evaluate the circuit´s resilience to SEU events. In this paper, we present an analytical model for SEU induced transients in combinational circuits. The pulse width of the voltage glitch due to an SEU event is a good measure of SEU robustness and our model efficiently computes it for any combinational gate. The experimental results demonstrate that our model is very accurate with a very low pulse width estimation error of 4% compared to SPICE. Our model gains its accuracy by using a non-linear transistor current model, and by considering the effect of tau_B of the radiation induced current pulse. Our analytical model is very fast and accurate, and can therefore be easily incorporated in a design flow to implement SEU tolerant circuits.