Choose a suitable board stack-up that supports
75Ω single-ended trace and 100Ω differential trace routing on the top layer of
the board. This is typically done with a Layer 2 ground plane reference for the
100Ω differential traces and a Layer 3 ground plane reference for the 75Ω
single-end traces.
Maintain a distance of at least 5 times the trace
width between signal trace and ground reference if
the signal trace and ground are on the same layer.
This prevents unwanted changes in the
characteristic impedance.
Maintain a consistent ground plane reference for each high-speed trace from source to endpoint. Ground reference discontinuities lead to characteristic impedance mismatch.