GROUNDED: EMC/EMI & PCB Design Nuggets

In circuit design, small details drive big problems.

Take ribbon cables, for example.

To save costs, engineers often reduce return paths:

“We don’t need multiple wires.”

“One thicker cable will handle the current.”

Sounds logical, right?

Except it ignores one key detail: electromagnetic fields.

Fast forward to your EMC certification:

- Suddenly, radiated emissions spike above 300 MHz.

- Your design fails, and now you’re scrambling to troubleshoot.

Here’s the fix:

Keep your signal and return path adjacent.

Why?

Because emissions are directly proportional to the loop area.

Bigger loop = bigger emissions.

TLDR:

🔹 Tighten that current loop (signal-return).

🔹 Keep return paths low impedance.

🔹 Save yourself costly certification retries.

Cut costs where it makes sense — not on EMC-critical connectors.

- Dario

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