Minimizing Crosstalk In PC Board Layout

In this ongoing series on PCB layout from the design team at PNC, previous posts have looked at some of the initial steps to turn a circuit schematic into a manufacturable, reliable PCB. These posts have looked at component placement, selecting appropriate trace widths, and BGA routing. In this post we are going to take a deeper dive into methods for reducing crosstalk in the PCB design. After the power and ground have been routed, the next task is to route high speed signal traces, and the traces that could either generate or receive crosstalk.

What is Crosstalk?

Crosstalk occurs when the signal on an aggressor trace on a PCB appears on a nearby victim trace, due to capacitive and inductive coupling between the two traces. Typical aggressor signal traces are:

● High speed digital signals, especially clock signals
● Noise from switching power suppliers
● High frequency RF.