Logical Effort Models with Voltage and Temperature Extensions in Super-/Near-/Sub-threshold Regions

Abstract

The voltage-/temperature-induced delay estimation error of conventional logical effort is much more severe in near/sub-threshold region. In this paper, super-/near-/sub-threshold logical effort models are proposed to eliminate delay estimation error caused by voltage and temperature variations. These models establish over the four different nanoscale CMOS generations. They also take environmental parameter variations with wide supply voltage 0.1 similar to 1V and full temperature -50 similar to 125 degrees C range into account. The simulation results are using UMC 90-nm, PTM 65-, 45-and 32-nm bulk CMOS technologies, respectively. The average absolute error among the three regions are only 6.01%, 4.12%, 8.01% and 6.55% for UMC 90-nm, PTM 65-, 45-and 32-nm technology, respectively. Proposed models extend the original high performance circuits design in super-threshold region to low power circuit design in near-threshold and sub-threshold regions. They are useful for future green electronics applications.