Sub-threshold SRAM

A 256kb sub-threshold SRAM operates below 400mV from 0 to 85°C and is implemented in 65nm CMOS technology. For the same 6 sigma static-noise margin, the sub-threshold SRAM at 0.4V achieves 2.25-times lower leakage power and 2.25-times lower active energy than its 6T counterpart at 0.6V. The SRAM uses a 10T bitcell to enable sub-threshold functionality.