I don't know if this is a problem with the software i am running, or the way i am trying to go about doing this. But every time i try to place the 74LS04 IC in Eschema it only shows the option to place the symbol for the inverter gate instead of the actual chip. i have tried re installing the 74xx library multiple times but no dice. i also tried typing ic after the chip name , because i know other programs run it that way, like Multisim but it did not work either.

If it helps to know i am running a Debian system with the 4.0.5 version of KiCad.

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2 Answers 2


The part you are wanting to use is a hex-gate part. Now there are two valid ways to deal with this in an eCAD suite.

  1. Have a single part with all 6 parts (and power) and then you connect nets akin to how you would physically
  2. each aspect of a multi-chip has its own symbol (and sometime a dedicated power unit)

The general consensus within KiCAD, especially with regards to the KLS is to follow #2


For symbols with multiple units that are drawn separately, where the units share common power pins, a separate unit should be drawn which contains these power pins.

In short, those Unit {A,B,C,D,E,F} you can see are inverters 1,2,3,4,5,6 and Unit G is the dedicated power. This does provide a cleaner schematic BUT this does offer the option that bad electronic engineers can place different units on different sheets...

Please review a similar question.

How to route Vdd and Vss to CD4011 in Pcbnew

Also I recommend upgrading to v5. I do not know if Debian has this in their repo's but the improvements are vast.

  • 1
    \$\begingroup\$ I do not agree that it is a bad idea to have the different units (gates) on separate sheets. In a proper hierarchical design this might even be desired. (Think about a multi channel amplifier where you need only one opa per channel but use a quad opa.) In such a case one would design one sheet that holds everything required for dealing with one "gate" and instantiate it once for every channel. \$\endgroup\$ Apr 3, 2019 at 22:37
  • \$\begingroup\$ @RenePöschl depends... I have seen horror's over the years... Where I have worked for the last 20years for some reason the eCAD librarian process calls for connectors to have a single part per pin for a connector. BAD electronics engineers then put the pins where they use them. On a 100 sheet schematic where pin1 is on sheet 5, pin2 is on sheet 7... this is BEYOND painful to review or use. Now split chip's is a bit easier as the function is easy (its an inverter) BUT if bad eEngineers do not lock packages then 1 unit could be connected to a function on the other side of the card... \$\endgroup\$
    – user16222
    Apr 3, 2019 at 22:41
  • \$\begingroup\$ so in principal I do agree BUT it is far too easy for a bad engineer to do something REALLY bad... Don't get me wrong I like it and at the moment I am submitting tickets to KiCAD git for parts and capturing a motor-drive and I have a 6switch inverter as a multi-unit and it vastly helps with schematic capture, but I don't do silly things in capturing ;) \$\endgroup\$
    – user16222
    Apr 3, 2019 at 22:43
  • \$\begingroup\$ You are right that it is silly to do this for a connector. But it is definitely a good idea for things like multi gate parts and also for complex ICs like an FPGA (That can not really fit on a single schematic page anyways) And of course the designer needs to take care how to use such a feature. And of course the layout needs to be able to influence which gate of which ic is used for what part of the circuit. \$\endgroup\$ Apr 3, 2019 at 22:44
  • \$\begingroup\$ exactly :) and if you note EXACTLY what I wrote in my answer, it was that multi-unit does offer a cleaner schematic BUT enables bad engineers ;) \$\endgroup\$
    – user16222
    Apr 3, 2019 at 22:46

This is the way how these symbols are defined in the library. They have their gates in separate units. In the version 5 libs there is also a separate unit for the power pins for some of these. The others sadly still have the power pins as invisible pins. (Legacy problem that we did not get around to fix.)

This is done to make schematics easier to read. (A schematic is an abstract representation of a circuits function. Only the layout side of things needs to care about how the physical part really looks like.)


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