Reference Designators for multi channel chips eg 74HC00

Many chips have more than one channel. For example the 74HC00 has four separate 2-input NAND gates. If I add four NAND gates to my schematic Scheme-It insists that they all have different Reference Designators when in fact it is perfectly reasonable for all four to share the designation “U1” as they are all on the same chip.

I could in theory turn off the RefDes display, assign a fake RefDes (eg “U900”), then put the real RefDes in the PartNumber field. But that seems pretty clunky and would mess up the BOM. Suggestions?

Hi @msa01

Scheme-it currently supports multi-gate symbols for a limited number of parts with pre-built symbols in the Digi-Key Catalog. An example is part number 296-42825-ND. Unfortunately, the application doesn’t currently offer a way to manually combine the reference designators to make multi-gated symbols.

Would you like to request this functionality be added as a future feature in the tool?


Thanks for the reply. Well, some way of handling chips which have multiple gates without having to give each gate its own reference number would seem like a good idea. But perhaps nobody uses chips like that any more although I see DigiKey has over 100,000 74HC00 chips in stock.

Lacking that feature I’ve given up on Scheme-It and now use Kicad.