Differential Trace Design Rule

Differential Trace Design Rules Truth vs Fiction:There is no shortage of design rules available when people talk about differential traces on circuit
boards. At various times you can hear people argue that there is a need for, or there is no need for, a
variety of special rules. In general, the rules fall into one or more of these five categories:
Planes: There must be a continuous power system plane underneath the differential pair.
Length: Care must be taken to ensure that differential traces are of equal length.
Spacing 1: Care must be taken to place the traces as close together as possible.
Spacing 2: Care must be taken to ensure that the spacing between traces is constant
everywhere along the length of the traces.
Impedance: Differential impedance rules must be applied.