A process-variation-tolerant dual-power-supply SRAM with 0.179µm2 Cell in 40nm CMOS using level-programmable wordline driver

A 512 Kb dual-power-supply SRAM is fabricated in 40nm CMOS with 0.179 mum 2 cell, which is 10% smaller than the SRAM scaling trend. The smaller cell size is realized by channel area saving. To improve the cell stability of the small channel area cell, we use a WL level-control scheme generated from dual power supplies in the WL driver. An adaptive WL-level programming scheme and dynamic-array-supply control increase SRAM operating margin. As a result, the cell failure rate is improved more than three orders of magnitude compared to the conventional dual-power-supply SRAM.