Does electricity work like water in the pipes?

Many of us approach printed circuit board design as if we are plumbers.

We’re still stuck with the idea that electromagnetism in a PCB works like water flowing through pipes, thinking we just need a closed circuit loop for the electrons to "flow" and make the circuit work.

This way of thinking about PCB design, and electronics in general, is flawed.

The problem with believing that electrons do the work, instead of electromagnetic fields, is that electron flow, or electron drift, has a velocity of only a few millimeters per second, not even close to the speed of light.

So how can we explain the high-speed components like DDR memory functioning?

It's because circuit board design is all about the electromagnetic fields, how we contain and redirect them, and at the speed of light in the dielectric between the conductors.

Not inside the conductors themselves.

This is how I like to visualize my layout, thinking about how the EM fields propagate in the dielectric in between the traces and planes, not like water in pipes.

The result?

EMI is no longer an issue, it’s actually the beauty of the design.

I dive deeper into these concepts in my free PCB Design for Low EMI Academy.

If you are interested, you can check them here: fresuelectronics.com

I hope this helps,

Dario

fresuelectronics.com

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