A Low Power SRAM Cell with High Read Stability

Abstract

In this paper, a 9T static random access memory (SRAM) cell design which consumes less dynamic power and has high read stability is proposed. In conventional six transistor (6T) SRAM cell, read stability is very low due to the voltage division between the access and driver transistors during read operation. Existing 9T SRAM cell design increases the read static noise margin (SNM) by twice as compared to conventional 6T SRAM cell by completely isolating the bit-lines during the read operation. But the write operation is performed in this cell, by charging/discharging of large bit line capacitances causing 22.5% increase in dynamic power consumption. In the proposed technique, the SRAM cell utilizes charging/discharging of a single bit-line (BL) during write operation, resulting in reduction of dynamic power consumption by 45% as compared to a conventional 6T SRAM cell while the read SNM is also maintained at twice the read SNM of the conventional 6T SRAM cell. All simulations of the proposed 9T SRAM cellhas been carried out in 0.13 ¹m CMOS technology.