UM8810PAIO DIY 3.3V VRM Module \ VOGONS

UM8810PAIO DIY 3.3V VRM Module

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First post, by Ganz-HUNGARY

Posted on 2018-10-31, 16:52

Ganz-HUNGARY Offline

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Joined: 2013-03-15, 16:51

Hi!
I found this mobo somewhere here at home. And for the most part, it works, with a modded RTC. But, it's capable of running a 5x86. And I have no VRM Module. Can I use an ATX PSU, and connect the 3.3V rail directly into the VRM socket? The pinout is like this: The top row is 5V, and the bottom row goes to the cpu. Using jumpers, we can use 5V CPUs.

Reply 1 of 3, by quicknick

Posted on 2018-10-31, 21:27

quicknick Offline

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That's actually a neat idea, I don't see any reason it wouldn't work. Just make sure the CPU power plane is completely isolated from +5V (so you don't have a short between 5V and 3.3V rails.

Reply 2 of 3, by ahtoh

Posted on 2018-11-01, 05:02

ahtoh Offline

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There's a high chance it will not work or will work unstable.
The PSU will not provide clean and stable 3.3v
Your chances will be higher if you add bypass capacitors close to the CPU

Reply 3 of 3, by Ganz-HUNGARY

Posted on 2018-11-01, 14:12

Ganz-HUNGARY Offline

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Rank: Newbie
Posts: 16
Joined: 2013-03-15, 16:51

Yes, I was thinking about adding some, like 6,3V 1000 micros. And a small inductor for noise canceling. Like 4-5 turns around a ferrite core as a choke.

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