New Analyses of Distributed Rc Interconnections

This paper gives new methods for calculating the time-domain response for a nite-length distributed RC line. We begin with the solution for di usion in a semi-in nite distributed RC line [4, 12] and apply the method of images (re ections) to obtain the voltage response for a nite-length RC line. Second, we describe a general approach for calculating the time-domain response for nite RC lines with source and load impedances. Next, we obtain new approximate analytical expressions for the voltage response in a nite RC line with resistive source and capacitive load. Delay estimates using this method are very close to SPICE-computed delays; we compare against both SPICE and the recent method of [12] which calculates delays in an RC line with capacitive load. Our method is simple; for higher accuracy in the response, additional terms can be computed using numerical techniques.