DIFFERENTIAL SIGNAL Design Rules-Or Not

摘要

Periodically, questions about differential trace design rules come up. There is always confusion over whether it is nec-essary to route differential traces close together, whether a plane needs to be underneath differential traces, or whether to consider differential impedance design rules with differential traces. In one sense, the answers to these questions are dif-ficult, but in another sense they are simple. In fact, if we are not concerned about signal integrity issues, there are no design rules at all. Here is my way of trying to clarify things.