Soft Error Hardened Asymmetric 10T SRAM Cell for Aerospace Applications

Abstract

Soft error in SRAM cell is one of the major reliability concern under aerospace radiation environment. A soft error occurs in SRAM cell due to charged particle strikes on sensitive nodes. In this paper a radiation hardened asymmetric 10T (AS10T) SRAM cell is presented to enhance the soft error hardening. The proposed cell uses read decoupled path to improve read static noise margin (RSNM) and voltage booster connected between storage nodes to improve node capacitance and hence enhanced radiation hardening. The proposed AS10T cell has a 75.83% higher critical charge as compared to 6T SRAM cell. For validation of soft error hardening of the proposed cell soft error rate ratio with supply voltage and temperature change is calculated and it is found that the AS10T has 6.41× and 3.2× less soft error rate ratio compared to 6T SRAM cell respectively. To better assess soft-error resilience and performance of the cell we introduce reliability stability to energy area product (RSEAP) ratio as a performance metric. Our analysis indicates that AS10T cell has 2.83× 1.6× and 1.36× higher RSEAP as compared to 6T RD8T and AS8T SRAM cells respectively. © 2020, Springer Science+Business Media, LLC, part of Springer Nature.