Power-Gated 9T SRAM Cell for Low-Energy Operation

Abstract

This brief proposes a novel power-gated 9T (PG9T) static random access memory (SRAM) cell that uses a read-decoupled access buffer and power-gating transistors to execute reliable read and write operations. The proposed 9T SRAM cell uses bit interleaving to achieve soft error immunity and utilizes a column-based virtual VSS signal to eliminate unnecessary bitline discharges in the unselected columns, thereby reducing the energy consumption. In a 22-nm FinFET technology, the proposed PG9T SRAM cell has a minimum operating voltage of 0.32 V while achieving the 6σ read stability yield. Compared with the previously proposed 9T SRAM cell, the proposed cell consumes 45% and 17% less energy per read and write operation, respectively, at the minimum operating voltage, and has a 12% smaller bit cell area.