How Harsh is Space?–Equations That Connect Space and Ground VLSI

Both space and ground are radiation-rich environments. Ensuring soft-error reliability is essential for both space and ground VLSI. Recent ground VLSI, particularly for automotive applications, has high reliability. It can be naturally considered for applications in space systems. However, estimating the space reliability of the ground VLSI is challenging. Space radiation is often regarded as ‘‘harsh’’ in comparison with ground radiation, but the magnitude of its harshness is unclear. The types of the radiation are different. Converting a ground soft-error reliability to space one is so far difficult. This study provides simple equations that can handle ground and space soft errors uniformly. The equations estimate the harshness of space at approximately 2500-times that of the ground. They also provide implications for the effects of dynamic voltage and frequency scaling on soft-error reliability. Advanced SOI and FinFET SRAMs respond to voltage scaling differently from classical bulk ones.