GROUNDED: EMC/EMI & PCB Design Nuggets

Electromagnetic interference (EMI) is a big problem when designing printed circuit boards (PCBs). It can turn a good design into a headache.

Today’s electronics are more complex, with faster data speeds, more components squeezed together, and stricter rules to follow.

This makes EMI in PCB design something you can’t overlook.

If you don’t handle it well, you might end up with products that fail tests, need expensive fixes, or don’t work reliably because of unwanted signals escaping into the air.

The key thing to know is that most EMI problems start inside the PCB itself, not from outside sources.

This article explains how to design printed circuit board (PCB) layouts to reduce electromagnetic interference (EMI) by controlling rapid current changes.

EMI is not black magic—it’s science you can understand (without a PhD).

Using basic high school physics, you can make your electronics pass electromagnetic compatibility (EMC) tests faster and more easily.

Read the full article here: https://fresuelectronics.com/post/optimizing-pcb-layout-for-emi-control

The faster you stop picturing electrons flowing inside conductors, the sooner you can turn EMI from black magic into something manageable.

What you see here is a simulation of the electric and magnetic fields in a PCB trace routed over the return and reference plane (commonly and wrongly called ground).

If you keep this picture in mind when routing Printed Circuit Boards, you’re already on a solid path to passing EMC tests without countless revisions.

This mindset helped me master the fundamentals of EMI control, allowing me to design electronics that passed EMC on the first try.

The reason EMI felt so elusive was that I was picturing the wrong concepts.

The primary reason we fail EMC tests because of EMI is not a lack of expertise, it’s the inaccurate fundamentals we’re often taught.

What We’re Commonly Taught:

Electricity is the flow of electrons through conductors, similar to water moving through a pipe.

What We Need to Understand:

Electricity is the transmission of an electromagnetic field through the space around and between conductors.