Power Pins and Supply Pins on CAD software

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#1
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I've been doing my circuit designs with Eagle PCB and I ran into some ambiguity. Some parts I use in my design have VDD pins that are marked as Supply Pins. Some other devices have VDD pins that are marked as Power Pins. I then realized I have no idea what the difference is, but Eagle still allows for both cases (Tried searching google for difference between power and supply and kept getting power supplies). By interconnecting them, I generate lots of warnings. I hate having AVR Studio puke warnings at me, and I hate having Eagle do it too. Should I make all my 3.3V and 5V pins and connections as supply pins or power pins? What's the difference?

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What does the net classes table say about your supply lines? Usually if you use parts from the supply library, the supply nets get the corresponding class automatically assigned to them.

The Dark Boxes are coming.

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Here is my ERC check and my net list, I don't think this is the right netlist table that you were talking about though, its the only one I know about... thanks

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I tend to ignore those warnings in Eagle ERC. The ones with power connected to ground do get my attention.

Jim

Jim Wagner Oregon Research Electronics, Consulting Div. Tangent, OR, USA http://www.orelectronics.net

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It seems that your libraries are messed up, which is perfectly normal for Eagle, unfortunately. Every pin can be supply, passive, input, output, i/o and probably something else.

If you absolutely can't live with this, open the library for the offending element and change that pin to Pas. I edit Eagle libs a lot, for example I tend to change SwapLevel to 1 for all pins. I don't want some stupid software to dictate me where I can swap pins and where I can't. They are my pins. And while laying out a board, swapping pins can save dozens of vias.

The Dark Boxes are coming.

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OP, are you using the "wire" tool or the "Net" tool to connect your pins? The net tool is the correct one.

Cheers,

Ross

Ross McKenzie ValuSoft Melbourne Australia

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Wire tool. Definitely wire tool, thanks for all the responses everyone. I learned something today, resolved my problem by setting things as passive in the libraries and have begun using the Net tool. I don't know what Eagle intended by all these different pin types and I guess I'll never know, stupid software

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There is a good discussion on this topic in the Eagle forum:
http://www.eaglecentral.ca/forums/index.php?t=rview&goto=137701&th=43887

Markus

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valusoft wrote:
OP, are you using the "wire" tool or the "Net" tool to connect your pins? The net tool is the correct one.

As long as you don't play with the thick blue busses those tools are more or less interchangeable in Eagle. I've been using this weird ware for 6 or 7 years already and I still can't tell the difference between them for sure.

If I were them, I'd start with throwing the crappy libraries out of the window though, starting with the RCL one. 0805 pads with clearance that doesn't allow a 0.254 trace pass through! That's the winner.

The Dark Boxes are coming.