SOP-4(ish) - Page 1
Forum section: electronics / general

author: PlainName
author_rank: Super Contributor
timestamp: March 15, 2024, 08:39:38 pm
content: Looking at some optocouplers:https://www.lcsc.com/products/Optocouplers-Phototransistor-Output_351.htmlSpecifically wanting a common SMD format which can be populated by multiple sources if necessary. So, SOP-4 looks reasonable and there's the list of 21 SOP-4 optocouplers. But half of them seem to be 2.54mm pitch and the other half 1.27mm pitch. They can't both be SOP-4, so which isreallySOP-4? And what should the other lot be called?

author: DavidAlfa
author_rank: Super Contributor
timestamp: March 15, 2024, 08:50:09 pm
content: The first one is SOP-4 100mil, the 2nd one is just SOP-4.Is it really that hard to google "Optocoupler packages" ?https://www.vishay.com/docs/49633/sg2098.pdf

author: thm_w
author_rank: Super Contributor
timestamp: March 15, 2024, 09:08:25 pm
content: Better to always check and not assume anything, IMO.SOIC has various widths, I would not assume if they said "SOIC" only that it meant wide or narrow. Even Vishay themselves just write "SOP4" in the datasheet title.

author: PlainName
author_rank: Super Contributor
timestamp: March 15, 2024, 09:13:44 pm
content: QuoteDid that, hence the confusion of which is actually SOP-4 - the wide one seemed to be 'real' SOP-4 but you say it's the other one

author: PlainName
author_rank: Super Contributor
timestamp: March 15, 2024, 09:15:11 pm
content: QuoteWell, of course I would check the final choice, but knowing what to search for in order to make a choice that can be checked is part of the problem. Waste of time searching for the one I don't want

author: DavidAlfa
author_rank: Super Contributor
timestamp: March 15, 2024, 09:21:32 pm
content: Still this is one of these packages triggering all alarms before production, can't trust pictures or descriptions, check the ordering code in the datasheet to make sure that it's the good one!Same as the ususal soic/wsoic screw-up!If your layout allows it, it's best to combine both footprints so you can use any when the next epidemic comes!

author: nctnico
author_rank: Super Contributor
timestamp: March 15, 2024, 09:31:49 pm
content: Quote from: PlainName on March 15, 2024, 09:13:44 pmAlways check the datasheet. There are many manufacturers who use the same name for an entirely different packages. Like QFN for example. These exist in 0.4mm, 0.5mm and 0.65mm pitches. And different case sizes as well despite having the same number of pins. I have stopped going by chip package names a long time ago.

author: thm_w
author_rank: Super Contributor
timestamp: March 15, 2024, 09:43:50 pm
content: Quote from: PlainName on March 15, 2024, 09:15:11 pmSure, but that only works on sites which properly enter all of the data.From your link LCSC has: SOP-4, SOP4-2.54mm, SOP4-2.8mm, etc. so you'll have to dig through to find what you want, assuming you want to check everything.

author: PlainName
author_rank: Super Contributor
timestamp: March 15, 2024, 10:01:57 pm
content: QuoteYes, I was thinking that might be a reasonable solution, though not so hot when space is at a premium.

author: PlainName
author_rank: Super Contributor
timestamp: March 15, 2024, 10:06:52 pm
content: QuoteDing! Thank you - I've twigged nowI thought that SOP-4 was a specific package but instead it seems to be a parent style for particular formats. That is, there isn't a simple SOP-4 package and instead it is always qualified. Except for manufacturer's data because they assume the one they use is the real one.