Electronics Forum / CAD / March 2005

Does anyone have a document that described the Pads Ascii file format?
I am a Protel user trying to import a large Pads PowerPCB V3.5 Ascii
file.  It imports 99% correctly, all except the split planes.  If I
understood the Pads Ascii data a little better (particularly the x and

  The LM324 model from TI works fine,but the one from National
Semiconductor is junk.
  I tried numerous Analog Devices models for various rail-to-rail
opamps, and found that almost all i tried gave me the same kind of

I want to ask a question:
I am doing a project which needs a DSP chip with BGA package. It has
272 pins. Is double layer PCB enough for routing?
Thanks!

What is the easiest way to set initial node values with .NODESET
command in SuperSpice? As I understand default initial guess is 0 Volts
for all nodes; can that be changed to, say, 60V for all nodes?
Can it be done within .subckt so that all +pins of all subcircuit of

I need to analyse VERY simple circuit with SuperSpice (or should I use
some other program?). Schematics has some resistors and 'special type'
of (coax)amplifiers. All that I know about those amplifiers is that
their U*I=22,5Watt, but that should be all that I need. It is connected

In Pads Logic, how to define a component with BGA pins?
For BGA package, the pin numbers are defined as
A1, A2,... A9;
B1, B2,... B9;

I could not find much info on users of FreePCB, so I started a Yahoo
group. FreePCB is an open source program for PCB layout. It works with
a PADSPCB netlist from any schematic package.
http://groups.yahoo.com/group/FreePCB/

  Any cheap systems that does that?
  With (relatively) modern op-amps?

I want my subcircuit to have variable/parameter/value. Something like
every resistor has resistance.. So, when I draw schematics, its very
easy to change resistor value and each and every resistor can have
different value. I want that same thing for my .subckt and not to have

BOM creation in PCAD seems really weird. It doesnt group all the same
component types in the same row in the BOM.
eg.
if R1,R2,R3 are all the same type and value, they should occur in a

I am not able to find out how to rename a sheet in a particular schematic.
I can change the name of the schematic but not able to change the name of the sheet.
Thanks
Mohit

My boss wants to proof circuits with component/net netlists in a
condensed readable fashion, however Protel 2004 only produces one, as
far as I can see, and he doesn't like the format.
Can I generate a different ascii netlist format?

I was once told by a professional layout person that leaving a 90
degree inside corner on intersections of traces and/or pads was not
good.  Seems the acid is harder to wash out of the little corners and
can result in over etching.  I have seen tons of boards that don't

For general reference, if there is an instance where certain mounting
holes should be part of a chassis ground net, is it proper to give
them a part number and include them in the schematic, or is it ok to
just electrically connect them on the PCB side with no record of them

In a multi-layer pcb, if I have a via going from the top layer to the
bottom layer, is it necessary to have a full pad on the inner layers, or
just on the layers where there is a connection to the via?  For higher
density cards, reducing or removing the anular ring in inner layers ...