Electronics Forum / CAD / March 2008

I've not used PADS, but have used Protel almost daily for the last 8 years,
and OrCAD before that. If PADS works in a similar fashion, then you won't
really be helping.

I've also had people generate schematics for me in Protel thinking they were
saving me time. It doesn't. Not unless you have my libraries. Regardless of
how pretty the schematic is, I will always have to completely redraw it to
work with my existing libraries which are usually not drawn is the same way
as the client would have. Since the library part defines the footprint it'll
always need redone. Incidentally, I can import schematics from several other
CAD packages, but would never use it for anything other than a template to
help redraw the schematic. Imported schematics never seem to work in the
same way as a natively drawn one.

Seriously, just give him what you have and let him do his part without the
constraints of a crappy imported schematic.

Chris

Well there ya go Dirk.
Providing a schematic from a cheap capture package
does not help the layout Person. It only invites more
chances of errors.
Cheers

So use gschem under windows.

Try www.FreeBSD.org then :p

Anyway both KiCad and gEDA/gschem is available in both win32 & Linux

Hi Brad,

OrCAD/PADS seems to be a popular combination, at least on the west coast here.

Let me add to your informative post: While it certainly is viable to use a
different schematic capture and PCB package, what you normally lose includes:

-- The ability to "trivially" (quickly) swap equivalent gates within a package
or equivalent pins within a gate.  Most PCB/schematic capture packages can do
this with "is/was" files *and the PCB guy having knowledge of what the
allowable swaps are* (this information is in the schematic library files but
not a PCB netlist), but this makes it somewhat klunkier (slower) to get done.

-- The ability to apply various layout rules based on net class.  E.g., your
have your clock net class, your differential pair net class, your power net
class, etc. and the PCB package automatically sets the right defaults (clocks
might need to be routed point to point rather than in a home-run topology,
power nets are far, diff. traces have matched lengths, etc.)  This can
sometimes be overcome with 3rd-party software -- for OrCAD/PADS Prescience
(http://www.precience.com/pages/PCBNavigator.asp) seems to be the well-known,
get-out-your-checkbook-and-weep solution.  For small designs going around and
defining a bunch of net classes usually isn't that big of a deal since the PCB
guy can just go around and do the same thing in his tool... for big designs
schematic capture and PCB layout are potentially far enough removed that you'd
really prefer to have the schematic "drive" the layout with such rules.

---Joel

[Fixed top posting]

I agree with Brad. Most PCB packages can also export a netlist based
on the actual routed tracks. This netlist can then be compared with
the orignal netlist exported from the schematic package. If a suitable
netlist format is chosen, then it does not take too long to manually
compare the netlists and hence ensure that the PCB represents the
schematic.

Regards
 Anton Erasmus