A 0.2 V–1.8 V 8T SRAM with Bit-interleaving Capability

Abstract

An 8T SRAM with bit-interleaving capability is designed for ultra-dynamic voltage scaling applications. An adaptive body-biasing scheme is designed to improve the stability of 8T cell, which achieves 1.5 times higher noise margin compared to the non-body-biased 8T cell. Also, a write driver is presented to enable the bit-interleaving structure, thus achieving high soft-error tolerance. A prototype 1-kb SRAM is fabricated in a standard 0.18 µm CMOS process. The measurement results show that the proposed design fulfils the functionality under supply voltage from 1.8 V to 0.3 V (0.2 V when the write wordline is boosted to 0.36 V) and the total power is reduced by four times of magnitude.