Spice provides signal-integrity clues for high-speed systems

Many engineers use a trial-and-error approach to fix transmission-line problems in high speed digital circuits. They experiment on the same interconnecting trace with series termination, parallel ac termination and sometimes both. There is a better way. Spice tools allow you to perform simple simulations with various termination and bus topologies. The simulations work equally well at 10 MHz or 10 GHz, and they do not need exotic high-frequency test fixtures. The simulation results can provide you with a seat-of-the-pants understanding of the behavior of a high-speed digital bus. For exotic and critical applications for which you can justify the training and purchase costs, more complex signal-integrity tools are available.