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Re: gEDA-user: gEDA on windows
John Doty wrote:
> On Jan 12, 2009, at 12:10 PM, Joerg wrote:
>
>> The only reason why I decided not to
>> use gschem is the sub-optimal handling of power pins in multi-package
>> parts and I am using tons of those.
>
> Can you describe what you see as the issue?
>
Ok, I'll try, it's been a long time since I tested it:
Take the LM324 as an example. It is a chip with four opamps in there:
http://www.national.com/ds/LM/LM124.pdf
When you place the first instantation it'll be pins 1,2,3, the next one
5,6,7 and so on. But all are supplied via the common supply pins 4 and
11. In gschem you only have two choices. Either you create a library
model that repeats those pins 4 and 11 visibly for all four
instantations or you create the library part with the power pins
detached where none of the instantations show power pins. This can be
practical for auto-connecting digital stuff to a VCC rail but it doesn't
work well in the analog world. Now you could also have pins 11 and 4 as
a separate "fifth" device. Anyhow, neither method looks professional,
neither is industry practice, and all make schematics more difficult to
understand for others. Especially for non-analog guys.
BTW, the same issue pops up when you need to design noise-sensitive
digital stuff. Often I have one 74HC14 on a seperate filtered power node
from all the others. For example if I create PWM controllers with it.
Doesn't work with inherent power pins.
Someone mentioned a fork that was done to fix that problem. But AFAIU
forked versions need to be compiled (not quite my turf) and they also
can lead onto a path away from the rest of the community here.
Kicad does not have this power pin problem but it has others. The worst
being a drawing frame that cannot be altered enough and cannot be
deleted at all because for some reason it was embedded in the code. So I
am still using Cadsoft Eagle but IMHO that has a major deficiency, no
hierarchical sheet structure.
My dream would be if the Kicad guys and the gEDA guys would hold a major
brewfest and combine their efforts. Probably the Kicad guys would prefer
red wine though. Got to have dreams :-)
--
Regards, Joerg
http://www.analogconsultants.com/
"gmail" domain blocked because of excessive spam.
Use another domain or send PM.
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