Semi-Analytical Current Source Modeling of Near- Threshold Operating Logic Cells Considering Process Variations

Abstract – Operating circuits in the ultra-low voltage regime results in significantly lower power consumption but can also degrade the circuit performance. In addition, it leads to higher sensitivity to various sources of variability in VLSI circuits. This paper extends the current source modeling (CSM) technique, which has successfully been applied to VLSI circuits to achieve very high accuracy in timing analysis, to the near-threshold voltage regime. In particular, it shows how to combine non-linear analytical models and lowdimensionality CSM lookup tables to simultaneously achieve modeling accuracy, space and time efficiency, when performing CSM-based timing analysis of VLSI circuits operating in near-threshold regime and subject to process variability effects. Index terms – near-threshold computing, statistical timing analysis, current-source modeling, process variation I