Impact of Near-Threshold and Variability on 7nm FinFET XOR Circuits

This paper evaluates ten different XOR logic gates arrangements behavior at near-threshold operation under process, voltage, and temperature (PVT) variability effects. The experiments adopt the 7nm FinFET High Performance and Low Standby Power technologies predictive models. At nominal voltages, high-performance devices show superior robustness for PVT variability, except to the influence of temperature over static current. However, near-threshold (NT) computing is a good option when lower power consumption is needed. According to results, the behavior of NT circuits under PVT variability should be highlighted, as it obtained lower values and more robustness than nominal approaches. Voltage variations inferior to 160 mV could provoke from 15% to 70% oscillation on delay. But, the same voltage variation could affect dramatically the total power deviations by 188% to 434%. Considering the different operation conditions explored in this work, the results provide valuable data and how the impact of variability is an important factor that must be explored to design more robust circuits.