Design of a stable single sided 11T static random access memory cell with improved critical charge

Radiation-induced soft errors are becoming a key challenge in satellite-based communication. The worst-hit component of such devices is static random-access memory bit-cells, owing to their high density, large area, and low-operating voltage. The unsuitability of conventional 6T SRAM for this purpose is ascertained by weak stability constraints, higher variability during process variations, and less tolerance capability in such a harsh environment. In this work, we have presented an improved, feedback charge-boosted, and read decoupled 11 transistors based (FC11T) SRAM cell. Its performance is assessed by comparing it with other low power, high stability, and soft-error-immune SRAM cells, namely, Asymmetric 8T (AS8T), Quatro 10T, PPN based 10T (PP10T), and loop cutting 10T (LC10T) cells over various design metrics. The attained observations establish that the proposed FC11T shows 1.13x/1.38x/0.90x/1.04x/1.03x improvement in critical charge compared to 6T/PP10T/AS8T/Quatro10T/LC10T cell. The read access time of proposed FC11T cell is reduced by 1.31x/1.17x/1.31x/1.41x/1.01x compared to 6T/PP10T/AS8T/Quatro10T/LC10T cell. The proposed cell further strengthens read stability by 1.97x/0.98x/1.91x/1.24x/1x when equated to 6T/PP10T/AS8T/Quatro10T/LC10T cell. Improved Inter-cell and Intra-cell soft error ratios represent improved soft error mitigation capability of the proposed 11T cell over 0.5 to 1 V supply voltage and 27 to 125 C temperature variation range. In addition to this, the proposed 11T cell also shows improved read stability and writability.

Automated summary

Radiation-induced soft errors are a significant challenge in satellite-based communication, especially in static random-access memory bit-cells. The unsuitability of conventional 6T SRAM for this purpose has led to the development of an improved FC11T SRAM cell, which exhibits improvements in critical charge, read access time, and read stability compared to other low power SRAM cells.