Interconnection of High-Speed Logic Circuits

The design of present-day logic systems, using circuits with transition times approaching 1 ns, meets with problems unless the transmission lines are properly terminated. It is very inconvenient to match the input and output of a logic circuit to the characteristic impedance of a transmission line, even at the cost of considerable distortion. An alternative method is to use lines of less than 5-cm length to reduce the distortion. However, many applications require longer lines, and some applications also require interconnecting logic circuits at various points along the line. This short note considers a method of dealing with this multiple problem using frequency domain, time domain, and experimental analysis.