This is about the U1A, U1B, U1C… symbol naming convention.
It works very well, but brings problems in certain cases pertaining to single devices with complex power connections.
Two examples:
DG419L SPDT analog switch. The symbol itself is nice and simple, but due to the fact that it has four power supplies, the symbol designer decided (understandably) to add a second power supply unit. Works fine, but has the side effect that the switch symbol is designated U1A instead of just U1.
Note: this is not just about the DG419, but a multitude of devices with difficult power schemes.
Single opamps. Same issue. Dual and quad opamps have a separate unit for power, which is fine. Applying this to a single opamp, it will get the designator U1A, which will lead a schematic reader to search for other opamps, thinking it’s a multiple device.
The KiCAD solution seems to be placing the power signals directly on the symbol, but this a also unsatisfactory. If you want to swap the +/- inputs, the power signals get swapped as well. Not good. (My own solution is a “DeMorgan equivalent” for single opamps, but that’s tedous to maintain).
Simply being able to suppress the A, B, C… suffixes in the schematic would solve the issue right away.
Do you have other suggestions? Perhaps I’ve overlooked something. If not, this post can be regarded as a feature request.
Why don’t you just unlearn the idea that the suffix is “ugly” and just leave it as is?
You can hide the RefDes and put something else in it’s place, but this can lead to hard to spot weird things in your project.
It’s got nothing to do with “ugly”, but with readability and clarity. Assigning the reference U1A to a single opamp leads the reader to search for (the non-existent) U1B. Waste of time for her/him.
That changing the “references” may result in problems for the designer (= me) is my issue.
The cool thing about @retiredfeline’s trick is that it doesn’t impact anything but the schematic view.
BTW, if you want to see schematic layout at its very best, check out the Dutch magazine Elektuur, English Elektor.
In fact, a major contributor here has recreated the Elektuur symbols as a library, which I installed myself immediately.
But that’s not true. There is a “B” section, and it’s the power supply pins. The last unit has been power supply pins in KiCad for quite a long time now, and it does not take much for newcomers to learn that. A simple way is to just hover over asymbol press [Ctrl + e] to load it in the symbol editor and then you can quickly switch between all units to see what they look like.
I admit it’s not ideal, but neither is hiding the RefDes and replacing it with something else.
And Elektor also does weird things sometimes. It’s also not really fair, as the schematics they print in their magazines are not made with an EDA program, but (re-) drawn in some DTP program, and this leaves details over to “artistic impression”.
Take for example this snippet (Elektor June 1980 6-16)
They modified some opamps to better fit the power delivery pins, and they grouped the type numbers of the opamps (there really are 6 of them in the schematic).
Or this snippet, where you also can only see which gate is in which IC with the accompanying text:
I do agree that the schematics in Elektor are drawn quite well, but it’s not because of the house style (well, maybe a bit) but mainly because of the orientation and placement of parts. They adhere quite well to “signals from left to right” and “voltages from top to bottom”. It does happen quite often though that they have to tug some section away in a bit of a weird place, but that is usually done to fit the schematic in a rectangle which has to be done for printing purposes and I find that quite acceptable.
I have of course also seen the elektor lib for KiCad, but never installed it. KiCad’s own symbols are just fine and I do not feel an itch for using someone else’s house style.
@paulvdh, Jeez, we’re really into the nitty-gritty here, sorry, I didn’t want to start a big discussion on a minor thing. It’s marked as “Solved”,
It’s about artwork, and yes, I regard schematic and PCB layout as “Artwork”. And everyone has their own style or priorities.
Yours are a bit different from mine, all good. Let’s leave it there.
I like working with KiCAD, and the possibility of little tweaks like this one makes it even better.
No biggie, maybe I exaggerated a bit by putting too much time in this, but there is no annoyance or other negative feelings.
I do agree it could be improved in some way, but not by the workaround of hiding the RefDes and replacing it with something else, because that can lead to confusing mistakes during later maintenance of the project. If it is to be improved, I think the place to do it is by modifying in how KiCad itself generates RefDes’s or displays them.
On the subject of the DG419.
I find the Kicad symbol aesthetically displeasing. I’d combine the two symbols into one and rename it DG419L… no part A & B.
The single Opamps would also have - & + pin swapping in my personal library. I wouldn’t create a second version as that would lead to a name suffix. Next time I used that amp I’d change the pins back if necessary. I did place a feature request to overcome this aesthetic problem here, but it seems to be failing badly. I don’t quite understand why,
Oh well, maybe one day it will happen.
To be honest, I also dislike the Post/Prefix refdes. As Eagle already did the same style it was soon accepted. Beside @mgyger eleektuur style lib, the old Tektronix schematics show also highly valuable artistic styles. E.g. see the scope model 454 or anything else around 1970. Everybody needs to find its personal style and I combine the Elektuur and Tektronix sytles. I also use the trick of switching refdes to unvisible and replace by everything shorter. Not only this: If there is a column of same symbols, my refdes are only visible at the top one. This is mainly useful for high pin count connectors what I always use with one unit per pin to arrange them in groups over the schematic.
Regarding Kicad, there are many ideas in this area what can be realized with the prerequisite of new V7 database introduction why its worth to keep the good ideas and allow users to use any flavour what is desired.
