EMI guidelines for PCB design

摘要

Knowing how the system functions, where the noisy lines are and where the sensitive lines with a low signal to noise ratio are in relation to each other can help optimise the board layout. EMI can be treated later on by adding filters at noisy points, or using metal enclosures that block radiation, but these can be expensive options and add time and cost through more testing and re-spins. With edge effects and connectors a key part of the EMI issue, these re-spins can even involve moving key I/O lines.