Traces must be routed with 50Ω impedance to
ground and 100Ω differential controlled impedance.
Route MDI traces to the transformer on the same
layer.
Use a metal shielded RJ-45 connector and
electrically connect the shield to chassis ground.
Avoid supplies and ground beneath the
magnetics.
Do not overlap the circuit ground and chassis ground planes. Keep chassis ground and circuit ground isolated by turning chassis ground into an isolated island by leaving a gap between the planes. Connecting a 1206 (size) capacitor between chassis ground and circuit ground is recommended to avoid floating metal. Capacitors less than 805 (size) can create an arching path for ESD due to a small air-gap.