A 14T radiation hardened SRAM for space applications with high reliability

Abstract

Static Random Access Memory (SRAM) is vital in aerospace applications, but it may experience soft errors in strong radiation environments. This paper proposes a reconfigurable radiation SRAM with two operating modes catering to different environmental requirements: (1) traditional triple modular redundancy mode used when the radiation environment is strong and (2) SRAM cell expansion mode used when the radiation is not very strong. For example, when the memory capacity of a single module is 8 k, the memory capacity is 8 k in traditional triple modular redundancy mode, but it can be tripled to 24 K in extended mode. As can be obviously seen, this design can adjust the size according to the needs. In SRAM cell expansion mode, the proposed 14T SRAM cell enables the memory to maintain radiation resistance. Compared with DICE, RHBD-12T, and WHIT, the read speed is improved by 3.8%, 5.7%, and 11.5% respectively, but compared with WE-QUATRO, the read speed is reduced by 1.9%. The hold static noise margin is 1.378 times than DICE, 1.201 times than WE-QUATRO, 1.045 times than RHBD-12T, and 1.14 times than WHIT, respectively. The proposed 14T cell in this paper exhibits the highest critical charge value compared with the other cells. Combined with the expansion mode of the reconfiguration design, it shows great stability.