A write bit-line free sub-threshold SRAM cell with fully half-select free feature and high reliability for ultra-low power applications

Abstract

In this paper, a robust sub-threshold 13 T-SRAM cell is designed, which in addition to reducing power and energy consumption can show high reliability and have the least error at low voltages. This cell is completely free from the half-select issue, which is one of the important factors in increasing power and decreasing reliability, especially at low voltage levels for SRAM arrays. It is designed without the need of write-bit-line, which according to the proposed techniques reduces the power consumption and significantly improves the write margin, also the lack of this bit-line in the memory array can reduce the total power consumption. The used bit-line only performs for read operation, therefore it has least activity. Also, an 8 Kb memory array is proposed to be able to perform various operations with less complexity, simpler logic and lower power consumption by proposing several techniques on peripheral circuits. All obtained noise margins according to proposed techniques have the highest values among the compared cells. The average power and PDP of the cell are less than all the compared designs, so that the average power and presented FoM has been improved by 6.83% and 18.46% respectively as compared to the best value of other designs.