How to make sure every unit of a symbol is used

[marera]

Is there a way to make shure every single unit of a symbol is used?
Example: I add 3 NANDs of a quad, the last one is left unused and not placed in schematic.
I do not get an error by ERC, wich is odd, for the unused inputs should be tied to GND.

[paulvdh]

Not an exact answer, but you may want to read this recent thread:

I am sooo frustrated - OpAmp power pins

Hi. I am using KiCAD 5.something. I am using an opamp (dual, 8-pin package) as a small part of a much larger circuit. It has power supply rails at ±30V; ±45V and ±15V (for the opamp). The ±15 may be derived from the 45V rails of fed by anoher board’s existing regulated 15 volt split rails. here’s the catch - the opamp symbols dont have power pins so I cannot assign them. I did a search on missing pins and the suggestion was to “view --> show hidden pins”. They are. I looked at the pin assi…

[retiredfeline]

IIRC there’s a issue submitted to Gitlab to improve this in future. You might want to vote for it. Sorry, you’ll have to search or someone will know it off the top of their head.

[davidsrsb]

Easy to find

Wishlist: ERC options to test for unused symbol units (lp:#1839250) (#1922) ·...

A report on where multi unit elements are in complex designs would be a bonus

[iabarry]

I think it would be less confusing to place all units at once. This would be good for dual opamps and logic gates. It wouldn’t work for giant FPGAs.

The user could be prompted when inserting a multi unit symbol. “ALL or just 1 unit”

[John_Pateman]

In 5.99 iirc there is a checkbox for 'Place all units ’ . The default behaviour is to do this.

[jmk]

@marera

Example: I add 3 NANDs of a quad, the last one is left unused and not placed in schematic.
I do not get an error by ERC, wich is odd, for the unused inputs should be tied to GND.

That is only necessary for Cmos…you are only protecting the chip by tying the inputs, and those inputs can be tied high or low or one each or to one of the other gate outputs; whichever is most convenient. That really has nothing to do with the circuit design, just good/necessary engineering practice.

Seems like a lot of programing work for not much result.

[retiredfeline]

Unfortunately if the missed unit is the power unit…

[marera]

Thanks for your hints, thoughts and opinions.
After 26 years of eagle, and 26 days of kicad, sometimes I wonder how good KiCad is, and sometimes I miss features, wich seem to be essential to me.
Regarding the multiple units in one symbol, eagle offeres 5 (spells five) different behaviours for every single unit to choose from, since at least 1995, vrs3. I used them, and I still find them to be useful.
However, you gave me the answers I needed.

[gmc]

This caught me out once. Now whenever I add the first unit, I add all the rest of them as well including the power unit.

[paulvdh]

As an intermediate & extra check, I have a habit of verifying unconnected pins while designing the PCB.

If you want to get methodical about PCB design, then spend some time on making a checklist of things you want to verify at different stages of the PCB design.