Impact of temperature fluctuations on circuit characteristics in 180nm and 65nm CMOS technologies

Temperature fluctuations alter threshold voltage, carrier mobility, and saturation velocity of a MOSFET. Temperature fluctuation induced variations in individual device parameters have unique effects on MOSFET drain current. Device parameters that characterize the variations in MOSFET current due to temperature fluctuations are identified in this paper for 180 nm and 65nm CMOS technologies. Operating an integrated circuit at the prescribed nominal supply voltage is not preferable for reliable circuit operation under temperature variations. A design methodology based on optimizing the supply voltage for temperature variation insensitive circuit performance is presented. Circuits display a temperature variation insensitive behavior when operated at a supply voltage 45% to 53% lower than the nominal supply voltage in a 180 nm CMOS technology. Similarly, the optimum supply voltages are 68% to 69% lower than the nominal supply voltage for circuits in a 65nm CMOS technology. The optimum supply voltages are similar for a diverse set of circuits in both technologies. The proposed technique of operating large scale designs at an optimum supply voltage for diminishing the performance sensitivity to temperature fluctuations is demonstrated to be feasible