Effects of Printed Circuit Board Transmission Lines and Loading on Gate Performance

Experimental measurements were conducted on a typical high-speed logic gate (AS04) driving a similar gate(s) as a load(s) and connected via a printed circuit board transmission line. This simple system was used to investigate waveform characteristics. The results show that rise and fall times are a function of position and are linearly dependent on fanout. The gate and line parameters are estimated from these measurements using both lumped and distributed models of the loads.