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Re: [Homebrew_PCBs] Pins and Pads for external connections

2006-03-18 by Alan Marconett

Hi Ted,

I saw parts with hidden supply pins get connected, but trouble is, there 
are many ways to call pins, VDD, VCC,  GND, VSS.  And Eagle doesn't seem 
to have a way to "alias" them together when they should be.

Did you notice the GND@1 and GND@2 convention?  you might try the @ 
convention to tie your pins together.

Time for my question,  I  just finished routing my board (by hand!), and 
I see that I  have vias that somehow have the wrong hole size?  They 
show up on the design rules check.  I have 12 mil signals and 24 mil 
power traces.  They need changed, but what's the spec?

Alan  KM6VV


kilocycles wrote:
> I'm re-doing some components I previously created (in Eagle, but this
> probably applies to other CAD pacakages as well).  The actual
> components, MiniCircuits SBL-1 RF passive mixers require several
> signal to be connectected externally.  This is an 8 pin through hole
> device.
> 
> Two of the pins are for discrete signals.  Two other pins are for one
> signal, and four pins are ground.  In Eagle, I've designated the
> ground pins as SUP (supply) and the other four as I/O.  I would think
> there should be a way to tie the two I/O pins together in the symbol
> that are supposed to be connected together extenally, but I haven't
> run across any symbols that tie pins together.  I have them tied
> pictorally in the Symbol drawing.  Also, I'm not sure if pads can be
> tied together in the Eagle Package for the device.  I can lay
> additional pads down that overlay and graphically link the ones
> defined for the pins, but they aren't logically connected when the
> Device is defined; they are just sort of lying there.
> 
> Without tying the pins and pads together in the Symbol/Package/Device
> definition, I have to remember that the two signal pins have to be
> tied to the same external signal, and the four ground pins have to be
> tied to ground, and not leave one or more unconnected.  It's not a
> real big deal, just a convenience.
> 
> There is a note in the Eagle Help topic on pins that states if any pin
> are defined on the Symbol as SUP (implying GND signal)that these will
> be automatically connected to GND as a net if a Supply symbol is used
> on the schematic; for example +12V, I presume. That's something else
> that's news to me.  I've used Supply many times, and I've yet to see
> any component automatically tie to GND.
> 
> Any ideas?
> 
> Ted
>

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