Overall Performance Improvement of Radiation- Hardened SRAM Cells through Assist Techniques

The harsh environment in space is characterized by high-energy particles and extreme temperature swings, which can cause single event upsets (SEUs) in conventional 6T SRAM cells. These cells are not resistant to SEUs and have a low critical charge (Qc), making them unsuitable for use in space applications. Radiation-hardened SRAM (RHSRAM) cells are an alternative to conventional SRAM cells, as they are resistant to SEUs and can recover from soft errors on their own. Researchers have proposed many different RHSRAM cells over the years, including the RHBD 10T, RHMD 10T, SRRD 12T, and RHPD 12T cells. This paper presents a simulation and estimation of the design metrics of these four RHSRAM cells. The results show that the SRRD 12T cell has the best overall performance, with the highest EQM (error-free memory) value. Finally, the paper proposes read/write assist techniques to improve the read/write design metrics of the RHSRAM cells. These techniques are shown to further improve the overall EQM value of the SRRD 12T cell.