Power Efficiency of 14 nm MCML Near Threshold Circuits

Near threshold circuits (NTC) are an attractive and promising technology that provides significant power savings with some delay penalty. The feasibility of NTC technology with MOS Current Mode Logic (MCML) based on a 14 nm FinFET process is examined in this work. A 32 bit Kogge Stone adder is chosen as a demonstration vehicle for simulation and feasibility analysis. MCML is shown to yield enhanced power efficiency when operated with a 100% activity factor above 1 GHz as compared to CMOS. Standard CMOS does not achieve frequencies above 9 GHz without a dramatic increase in power consumption. MCML is most efficient beyond 9 GHz over a wide range of activity factors. MCML also exhibits significantly lower noise levels as compared to standard CMOS. The results of the analysis demonstrate that pairing NTC and MCML is efficient when operating at high frequencies and activity factors.