Annotate swaps my IC parts…?


#1

What am I doing wrong here? I’m using an LM13700 from std lib and I have a schematic like this:

Each time I try to use annotate KiCad just swaps the parts to this:

It’s all messed up. Looking at the library entry, it’s definitely something fishy that the A unit is 12-16 and C unit is 1-5:

Is it just this entry that is buggy or am I doing something wrong?

Also, maybe this should be another question, but it feels pretty related:

I have two quad opamp chips TL074, for each schematic component I can choose A, B, C, D, but I don’t understand how I can manually edit the allocations into chips for optimizing the PCB layout?


#2

What happens if you select do not swap any annotated multi unit part?

Might be a mistake or they are refered this way in the datasheet. If it is really a mistake either make an issue over at the kicad library repo or better still fix it via a pull request.


#3

When a part has a power section like this, you cannot make parts interchangeable.
Looks like a library error at first glance.


#4

Agreed, it should have “all units are not interchangeable” checked.

The data sheet does not seem to distinguish between units, so I guess the part creator arbitrarily took the first one they came across as Unit A.


#5

Thanks! That seemed to work.

Yes, it actually swapped different parts that wasn’t interchangable as you can see in the screen dump so definitely wrong there. I too looked at the data sheet and couldn’t find any naming of the two sections like A or B, The schema I’m “copying” at the moment is however calling the lower pin no section A and the higher B which kindof makes sense to me…

Follow up question which is re-iterating my last bonus question in original post :slight_smile:

In the case where the units actually are interchangeable as in my quad op-amp (tl074), does the annotate function do some kind of try to allocate smartly since it interchanges? Or is that just to do a 1A through to 1D before adding another chip? Because Maybe I need some control over that to do the PCB design later on, right? I still don’t understand how I manually steer this allocation…?


#6

Right click on the unit you want to change -> Edit -> Unit -> select the unit you want.

As a test i placed all four units of the 7400 symbol. Annotated it (It seems to set it up a…d) And selected unit B for the one that previously has been unit A.

Before


After: (As you can see this tool does not exchange units. It sets the unit for the currently selected unit which will result in one unit being used multiple times.)