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Return Path Routing — Why No One Does It, But You Really Should

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temperance:
The idea is fine but difficult to apply with for example micro controllers in TQFP, BGA,... with signals starting and ending at all sides of the device. On a multi layer board that's easy enough and what nctnico suggested is the way to go. Spread via's as much as possible so that you don't put up "fences" in planes. Or worse even worse, gaps in planes.

For two layer digital boards someone learned me a different approach long ago when I didn't know much about those things. Place components as good as possible. Proceed with routing a web with power and GND between all the important things which need power. It divides your board into small squares/rectangles. The idea is to keep the inductance of the power and GND signals as low as possible. Of course you need more VIA's to connect all signals. But those via's don't hurt while a power distribution network with some inductance combined with high Q ceramic decoupling capacitors does hurt when an external transient makes it into the power distribution network.

SiliconWizard:
If you route BGAs on 2-layer PCBs, though, you're probably a bit masochistic.

temperance:

--- Quote ---If you route BGAs on 2-layer PCBs, though, you're probably a bit masochistic.
--- End quote ---

That's not what I wrote. I wrote: For two layer digital boards someone learned me a different approach long ago when I didn't know much about those things.

Xena E:
I've always wondered why this wasn't a 101 subject rather than being obscured in the later pages of grounding treaties.

Well done to the OP for the well written paper.

Worthy sticky?

 :-+ X

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