I am working on a circuit using the LTC3129 and would like to lay out a pcb using eagle. Can someone either generate the library or give me some hints on how to generate using ulp?
Bill
I am working on a circuit using the LTC3129 and would like to lay out a pcb using eagle. Can someone either generate the library or give me some hints on how to generate using ulp?
Bill
On 02/03/2014 12:35 PM, zmrbill wrote:
I am working on a circuit using the LTC3129 and would like to lay out a
pcb using eagle. Can someone either generate the library or give me
some hints on how to generate using ulp?
Good morning, Bill,
A User Language Program is not the right tool to generate this part.
All in all, it is a read-only environment and can not directly change
anything in the schematic, board, or library editors. That being said,
it can exit the program passing a string argument as a parameter to
exit() that contains a script to execute. The script can do anything
that you can type in the command text box.
I took a quick look at the datasheet for the LTC3129. The best place to
start is in the library editor with a personal library opened. It is
recommended to avoid editing any of the libraries that came with the
distribution - the changes will likely be overwritten by updates and
upgrades.
First, with the library editor open, create a new symbol that closely
matches the block diagram on the first page of the datasheet. Make sure
that the pins you add have the proper direction. PWR is for power and
ground pins. IN and OUT signify the direction of the flow of power or
signal. The ERC will warn you if you have more than one OUT on a net,
or if a net contains one or more IN's without an OUT. You can read more
about the characteristics of each direction in the manual.
Next, create a package that accommodates the footprint of the '3129.
Page 2 of the datasheet shows that this part is offered in two different
packages - a QFP and an MSOP. A suitable package may exist in
smd-ipc.lpr. If you find one there, you can drag it from the control
panel to the library editor to include it in your library. Don't forget
to add the center pad on the bottom of the chip. Pages 26 and 27 of the
datasheet has the recommended pad layouts.
Finally, create a new device for the '3129. Add the symbol you created
in the first step, and the package you copied or created in the second
step. Use the CONNECT to connect the pins on the symbol to the pads on
the package.
Save the library. Go back to your schematic and USE the library, then
UPDATE the library. At this point, you should be able to ADD the new
part to your schematic.
It is a good idea to know how to create your own parts. While the
libraries included in the distribution are extensive, they are far from
complete, and at the rate new parts are being invented, they will never
be complete. Additionally, there is no guarantee for accuracy on any of
the distribution libraries. Always verify the package against the
datasheet. I have had boards fabricated on more than one occasion that
wound up useless because I didn't check the layout.
There is more information on this process in the user manual and in the
tutorial. Look in the doc/ directory below Eagle's installation directory.
I hope this helps get you started.
Regards,
- Chuck
Hey thanks Chuck, I will use your reply as a guide.
I have been a long time user of Ltspice and the link between Eagle and Ltspice is what really attracted me. I also need to ability to design PCB.
Bill