Sub-threshold SRAM Sense Amplifier Compensation Using Auto-zeroing Circuitry

Device variability in modern processes has become a major concern in SRAM design leading to degradation of both performance and yield. Variation induced offset in the sense amplifiers requires a larger bit-line differential, which slows down SRAM access times and causes increased power consumption. The effect aggravated in the sub-threshold region. In this paper, we propose a circuit that reduces the sense amp offset using an auto-zeroing scheme with automatic temperature, voltage, and aging tracking. The circuit enables flexible tuning of the offset voltage.