GROUNDED: Your PCB, EMC/EMI, and SI Nuggets

EMC tests can be an electronic developer’s worst nightmare.

Especially when your reputation—or even worse, your job position—is at stake.

I’ve been in situations where the whole company was counting on me to finally pass the EMC tests so we could start selling the product on the marketplace.

Prospective clients are waiting for the results so they can get their product.

Your boss is waiting for the results so they can start seeing some cash inflow.

Your team is waiting for the results so they didn’t waste months of stress in vain.

You can cut the tension with a knife!

And you?

Well, you could be either with butterflies in your stomach...

or whistling around the hall because you know you’ve got this.

You’re so confident you’re going to pass that you’ve already booked a few days of holidays to celebrate and rest after these excruciating months of hard work.

But what does all of this have to do with this picture?

Well, actually, a lot.

See, understanding how the signals (or better yet, the EM fields) propagate in the PCB can mean many things.

For instance, it could mean that you understand:

- How to choose your stackup for low EMI, because it’s based on field containment, not electrons flowing through the copper

- How conduction and displacement currents influence the EMI results of your board

- How differential mode emissions can cause EMC tests to fail

- How common mode currents can drastically affect EMC results with just a few microamps

- How parasitics in your layout can determine the EMI signature of your board

- How the conductors in your layout can turn into antenna-like structures

- How impedance (instantaneous, characteristic, differential, etc.) can mess up your EMC compliance plans without you even noticing.

So yes...

This picture taken from my new EMI Control Guide can mean a lot in terms of EMC - and whether you’ll be celebrating with a holiday, or sweating through another round of tests.

-Dario

P.S. Want to make passing EMC tests on the first try a routine?

Grab my new EMI Control Guide Here: