Analysis of Transmission Lines on Integrated-Circuit Chips

The availability of very fast semiconductor switching devices and the possibilities of large scale integration have increased the importance of the interconnection problem for the design of high-speed computers. The interconnection delay represents a fundamental boundary which limits the ultimate speed of logic circuits. The transmission-line behavior of interconnections on integrated-circuit chips, especially for subnanosecond applications, is the prime concern of this paper. A lumped circuit model is proposed and justified on physical and experimental grounds. It is shown that interconnections behave like RC transmission lines at low frequencies, with the effect of inductance showing up at midrange and high frequencies. Some simple formulas are included for design use.