I’m trying to make a symbol for an op-amp that I’m using, a TL3472CD. It has the same pinout as an LM358, so I want to take the existing LM358 symbol and update some of the properties including the part name and datasheet link to reflect the new part.
I already have a custom library created with some other parts that I’ve made from scratch that I want to place this new part into.
In the schematic library editor, I have tried the following:
Find the LM358 symbol under the Amplifier_Operational library
Right click, and select “Copy Symbol”
right click on my custom_parts library, and select “paste symbol”
What should happen:
The single LM358 part is copied to the new library, allowing me to edit it and update properties.
What actually happens:
The LM358 part, as well as about 3 dozen other parts from the Amplifier_Operational library are imported. I then have to go through and delete these extra parts one by one. However, when I try to remove one of the parts, the rest of them also disappear.
How do I copy a single part? Am I doing something wrong?
This is because the symbol you try to copy has aliases assigned. Aliases are not really separate symbols this is why they behave a bit strange. (They are copied with the symbol as you discovered for example.) To “fix” this simply remove the aliases from the symbol after you copy it.)
Aliases are managed in the symbol properties dialog (reachable with a button in the top toolbar.)
If you run a curent nightly (or even v5.1) then you can use my tutorial for an explanation: Tutorial: How to make a symbol (KiCad v5.1.x) (Quite early on i explain how you get to the symbol properties dialog. In the second part i explain in detail how to add aliases. Deleting them is done in the same dialog with the button that looks like a recycling bin.)
If you are on version 5.0.x then this looks a bit different but aliases are still handled in the symbol properties dialog. There is a list of aliases in it where you should have some button to delete them. (I have no 5.0.x installed so i can no longer check how it looked like. So i kind of work from memory.)
I think the LM358 is an alias of another part (LM2904). Go into the part settings and remove the other aliases? This I think requires you to do what you are doing to the parent/top level part so ie the LM2904, then DELETE ALL in the settings Aliases Tab (then save YOUR library) and you should only have the one part.
For future reference, when looking at the list of symbols all the symbol names that are italicized are aliases. This nugget if information can help you from getting confused again.