Routing two single-ended signals as near as possible causes signal integrity problems – the most obvious one being crosstalk. Cross talk is a coupling effect that happens between two high speed signals.Crosstalk could be caused because of capacitive coupling or because of inductive coupling between the high speed traces.

These two types of coupling between traces give rise to two different types of crosstalk called near end crosstalk and far end crosstalk. It is possible to reduce the effect of crosstalk although it might be difficult to eliminate it.

The following rules have to be followed wherever possible to limit the effect of crosstalk between traces.

• Route traces in stripline instead of microstrip.
• Increase trace spacing between the singed-ended signal traces.
• Use a solid ground reference under traces wherever possible.
• Avoid running the high speed traces parallely for long distances.
• Do not share return pins in connectors.
• Use guard traces with vias connected to ground on the ends and throughout the length.
• Use stitching vias to provide a short return reference whenever traces are tracked over discontinuities.