A comprehensive study of energy dissipation in lossy transmission lines driven by CMOS inverters

In this paper, new formulations for the energy dissipation of lossy transmission lines driven by CMOS inverters are provided, and a new performance metric for the energy optimization under the delay constraint is proposed. The energy formulations are obtained by using approximated expressions for the driving-point impedance of lossy coupled transmission lines which itself is derived by solving Telegrapher's equations. A comprehensive analysis of energy is performed for a wide variety range of the gate. aspect-ratios of the driving transistors. To accomplish this task, two stable circuits that are capable of modeling the transmission line for a broad range of frequencies are synthesized. Experimental results show that the energy calculated using these equivalent circuits are almost equal to the one calculated by solving the more complicated transmission line equations directly. Next, using a new performance metric the effect of geometrical variations of the interconnect and the driver on the energy optimization under the delay constraint is studied. The experimental results verify the accuracy of our models.