Design of High-Speed, Low-Power Sensing Circuits for Nano-Scale Embedded Memory

This paper comparatively reviews sensing circuit designs for the most widely used embedded memory, static random-access memory (SRAM). Many sensing circuits for SRAM have been proposed to improve power efficiency and speed, because sensing operations in SRAM dominantly determine the overall speed and power consumption of the system-on-chip. This phenomenon is more pronounced in the nanoscale era, where SRAM bit-cells implemented near minimum-sized transistors are highly influenced by variation effects. Under this condition, for stable sensing, the control signal for accessing the selected bit-cell (word-line, WL) should be asserted for a long time, leading to increases in the power dissipation and delay at the same time. By innovating sensing circuits that can reduce the WL pulse width, the sensing power and speed can be efficiently improved, simultaneously. Throughout this paper, the strength and weakness of many SRAM sensing circuits are introduced in terms of various aspects-speed, area, power, etc.