GROUNDED: EMC/EMI & PCB Design Nuggets

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.

Why This Distinction Is Critical:

Understanding this concept makes practical guidelines easier to apply.

For example, maintain a minimum distance of three trace widths between signal traces.

Electromagnetic fields extend beyond the conductor, so if a signal trace is too close to another conductor, the field can influence it.

If that conductor connects to a cable leaving the board, the field may couple unwanted signals into the cable, causing radiation that EMC test equipment detects.

Key Point:

EMI is not "black magic."

The fundamentals can be learned without 40 years of experience.

-Dario

P.S. If you’re unsure which EMI fundamentals to follow, I’ve just put together an EMI Control Guides Bundle.

It’s available since yesterday with a 30% discount (limited offer). ​Check it out here: