Comment by eqvinox | Hacker News Reader

Comment by eqvinox | Hacker News Reader

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As the sibling notes, it started as SN7404… except that's still not the full part number; it's missing a trailing N for PDIP-8 (assuming that's what you meant, as it would be the historical reference)

Now to get from SN7404N to SN74AUP1T04DCKR:

SN74 is still the same

AUP gives you 1.8V logic, this "naming component" goes back to the 70s/80s with 74S

1 gives you a single gate rather than 6 of them. You should be ignoring these if you're looking for the 6-gate variant.

T gives you level-shifting capability. You should be ignoring these if you're looking for a "normal" chip.

04 is from the original 7404 name, for an inverter.

DCK replaces the N, indicating a SC70 2mm × 1.25mm SMD part

R is not part of the part number, it's an ordering specification for a specific reel size. You should be ignoring this while designing, until you need to worry about delivery details.

> all this adds up to finding parts being very annoying when building stuff

idk, I've never had problems due to naming schemes. Parametric searching is IMHO where things become painful.

> idk, I've never had problems due to naming schemes.

Concrete example, lets say I need 74123 in my project. If things were sane, I could just type in "74123" in Digikey search field and see what my options are. But you can't because this middlefix logic family thing. And searching for just "123" is completely useless.

Let's continue and say we go with the most jellybean 74HC family. Digging bit deeper I discover that in addition to the 74HC123 I was looking for, there is also 74HC4538, which has the same parametrics and same description. Yaay.

And just visually eyeballing the part numbers is pain because all the random prefix/middlefix/suffix characters that might or might not be meaningful.

I don't think finding basic jelly-bean logic parts should be this complicated. I can deal with analyzing the parameters etc, that is actually intrinsic complexity. But this part number stuff feels like just unnecessary bullshit getting in the way for discovering alternatives.

I suppose big players will use preferred manufacturers and predefined logic families, so this won't be a problem. And 74 series is not all that relevant these days anyways. But still some standardization would have been nice.

You should know which logic family you need before you even get searching - voltage levels and timing should be known beforehand, which will dictate exactly which families are suitable

> voltage levels and timing should be known beforehand, which will dictate exactly which families are suitable

TI alone has 13+ logic families for 3V3 for example, and all of them are faster than HC family (and thus usable for lot of applications). Nexperia has similar count, some of them are same-ish as TI, some of them are distinct. And other manufacturers have their own stuff. So that doesn't really cut down the options much.

Look at the table on page 7 of TIs "Logic Guide" for example https://www.ti.com/lit/SDYU001 or Nexperias "Logic Application Handbook" pages 293 onwards https://assets.nexperia.com/documents/brochure/Nexperia_LOGI...

Sure, if you are doing very fancy stuff, then you can boil all this down to some one specific family. But especially with 74 series these days when how often that is actually the case? And how often you just want some jellybean part that is easily available? And with part availability being what it is, I'd want to easily substitute parts from other logic families.

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