Single bit-line 11T SRAM cell for low power and improved stability

Abstract

This study aims for a new 11T static random access memory (SRAM) cell that uses power gating transistors and transmission gate for low leakage and reliable write operation. The proposed cell has a separate read and write path which successfully improves read and write abilities. Furthermore, it solves the row half select disturbance and utilises a row-based virtual ground signal to eliminate unnecessary bit-line discharge in the un-selected row, thus decreasing energy consumption. The cell also achieves low power due to the stack effect. To show the effectiveness of the cell, its design metrics are compared with other published SRAM cells, namely, conventional 6T, 10T, 9T, and power-gated 9T (PG9T). In standby mode, from 6.71 to 7.37% leakage power reduction is observed for this cell at an operating voltage of 1.2 V and 29.21 to 58.68% & 32.74 to 71.11% improvement for write & read power over other cells. The proposed cell exhibits higher write and reads static noise margins with an improvement of 13.54 and 63.28%, respectively, compared to conventional 6T SRAM cell. The cell provides write delay improvement from 29.77 to 49.40% and read delay improvement from 7 to 12% compared to 9T, 10T, and PG9T, respectively.