What does the N in 74**N stand for? - Page 1
Forum section: electronics / beginners

author: fabiodl
author_rank: Frequent Contributor
timestamp: February 04, 2021, 02:56:55 am
content: What does the N (sometimes AN) stand for?For instance,SN74LS273vsSN74LS273N

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: February 04, 2021, 03:02:11 am
content: Hi,The N means plastic DIP package.Jay_Diddy_B

author: fabiodl
author_rank: Frequent Contributor
timestamp: February 04, 2021, 03:12:50 am
content: Thank you!How about the A?Is that a revision?Let's say SN74LS166AN

author: rstofer
author_rank: Super Contributor
timestamp: February 04, 2021, 04:35:33 am
content: It's all spelled out in the datasheet:https://www.ti.com/lit/ds/symlink/sn74ls166a.pdf

author: fabiodl
author_rank: Frequent Contributor
timestamp: February 04, 2021, 04:46:40 am
content: Quote from: rstofer on February 04, 2021, 04:35:33 amDo you mean the power dissipation table?I saw that many more ICs usually have an A version a non A one, so I wondered if it is something generic (as the N for DIP)For instance quote from wikipedia:There are two versions of the SN76489: the SN76489 (Narrow DIP version labeled SN76489N) and the SN76489A (Narrow DIP version labeled SN76489AN). The former was made around 1980–1982 and the latter from 1983 onward. They differ in that the output of the SN76489 is the inverse of the expected waveform (the waveform 'grows' towards 0 V from 2.5 V), while the SN76489A the waveform is not inverted.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: February 04, 2021, 04:49:34 am
content: The data sheet rules. And to really be sure you need the specific manufacturer's data sheet. While there is a lot of conformity in the various codes around the numbers there are exceptions.

author: SeanB
author_rank: Super Contributor
timestamp: February 04, 2021, 04:57:34 pm
content: Quote from: Terry Bites on February 04, 2021, 04:21:59 pmFormal, as in the one from the original part designer or producer, not the tenth generation copy, of a poorly printed copy that has been variously lost, found, buried in a peat bog for nine months, and then filed by a Vogon.

author: fabiodl
author_rank: Frequent Contributor
timestamp: February 05, 2021, 10:47:54 am
content: Quote from: Terry Bites on February 04, 2021, 04:21:59 pmI was curious whether there was an "unspoken convention" (as for the N=narrow dip) which is notalwaystrue, but itoftenis.

author: BitsnBytes
author_rank: Contributor
timestamp: February 05, 2021, 02:28:56 pm
content: Let me tell you work around of part numbers.Every datasheet has a separate section for "Numbering Information" or "Ordering Information". You can easily check the meaning of any part number against the ordering information.Regards

author: Cerebus
author_rank: Super Contributor
timestamp: February 05, 2021, 04:00:25 pm
content: Quote from: fabiodl on February 05, 2021, 10:47:54 amYeah, that's pretty much correct. You can treat it as a hint, but woe betide you if you assume that it's always true. That particular convention was true forTexas Instrumentspartsaround the timethat the SN74xxx TTL logic family was first being produced and waslooselycopied bysomeother manufacturers second sourcing 74 series TTL parts. Note all thequalificationsin italics that sentence.Again, an A, or a B, or C, or D, following a major part number often, but not always, indicates a grade of component, selected on some defining characteristic. That characteristic might be power consumption, it might be offset voltage or drift for an op amp, it might be rated temperature range. In some parts it indicates alternative pin-outs. The range of uses is so wide that it's positively dangerous to make any assumptions.

author: edavid
author_rank: Super Contributor
timestamp: February 05, 2021, 04:57:17 pm
content: Quote from: fabiodl on February 04, 2021, 04:46:40 amYou are correct that TI (and Intel and a few others) used an A/B/C etc. suffix to indicate a revision, but other IC makers mostly did not, unless they were second-sourcing a part. It was often pretty difficult to find out exactly what was changed.

author: Simon
author_rank: Unknown
timestamp: February 05, 2021, 05:25:59 pm
content: The numbering system is old and manufacturers may have diverged. Where more that one manufacturer makes it under the same part do not assume that there is one data sheet.