New analyses of distributed RC interconnections

This paper gives new methods for calculating the time-domain response for a finite-length distributed RC line. We begin with the solution for diffusion in a semi-infinite distributed RC line and apply the method of images (reflections) to obtain the voltage response for a finite-length RC line. Second, we describe a general approach for calculating the time-domain response for finite RC lines with source and load impedances, Next, we obtain new approximate analytical expressions for the voltage response in a finite 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 Rao (1995) 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