This is why many PCB designs and electronic products fail EMC tests!
Oversimplified?
Maybe not.
In the majority of cases, the problem is that many have forgotten the core concepts... The principles...
I did so too for a while, so I don't blame you.
Many of us have forgotten that digital signals are composed of many other sinusoidal signals that form what we call a "digital signal".
In reality, there is no "digital signal". What we have is a trapezoidal signal with signal rise and fall times, composed of harmonic signals that all have different frequencies.
So it's not one single signal, but many of them, which we call harmonics.
Although strictly related to each other, their frequencies are not the same, and so are not their current paths.
The EMI problem comes when we neglect these details, and we design PCBs as if we were connecting components with one another, without really thinking about what goes on in between these connections.
The biggest problem we encounter is controlling the energy contained in these harmonic signals. The energy contained in these sharp rise and fall times.
This is where we encounter EMI issues.
This is when this energy finds a better path than the one you have assigned it already with your traces and planes in your PCB and starts to spread around.
And once it does, you have no more control over it.
This energy is then picked up by the testing instruments at the EMC lab facility during the test, and your product automatically fails.
That's it.
All this work and money for nothing. Now back to the drawing board.
Then rinse and repeat until something works. Maybe...
Unless...
You take action, you start watching the lesson in the classrooms, engage with the others in the community, and ask the questions that many don't want to ask.
We are here to support you so that you can become the master in this field.
So that you can get awesome results, and teach other how you did it.
I hope this helps,
Dario
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