Power Distribution

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#1
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Seems like years ago we were doing 74xx DIP designs and ran the VCC and GND around the rows of IC's, making a big loop in the process. Now with SMD and different sizes and orientations, the power run is going everywhere. Which is the better practice?
Just place the run where it's needed? (power1)
Or try to close that loop for better power distribution? (power2).
Or does it matter either way?

If it's number 2, I find it's difficult to do with Eagle since once all the points are wired, you can't add extra traces to that signal. Unless there's a trick I don't know about.

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I think I would avoid the loops, doing it more like Power1. Though, where possible, I would use a flood for the ground. And, depending on switching speed and the function implemented, I'd use bypass caps.

I also think that I might put supply and ground on the same side, leaving one side free to run signals.

Jim

 

Until Black Lives Matter, we do not have "All Lives Matter"!

 

 

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Yes there will be ground plane, but these boards can have +24, +15, -15, +5, and +3.3. Can't put them all on pours. This is just a simple example, caps would certainly be added.

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That does complicate. But, I would generally avoid loops. Just as a general principle.

Jim

 

Until Black Lives Matter, we do not have "All Lives Matter"!