EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: fabiodl on February 04, 2021, 02:56:55 am
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What does the N (sometimes AN) stand for?
For instance,
SN74LS273
vs
SN74LS273N
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Hi,
The N means plastic DIP package.
Jay_Diddy_B
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Thank you!
How about the A?Is that a revision?Let's say SN74LS166AN
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It's all spelled out in the datasheet:
https://www.ti.com/lit/ds/symlink/sn74ls166a.pdf (https://www.ti.com/lit/ds/symlink/sn74ls166a.pdf)
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It's all spelled out in the datasheet:
https://www.ti.com/lit/ds/symlink/sn74ls166a.pdf (https://www.ti.com/lit/ds/symlink/sn74ls166a.pdf)
Do 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.
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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.
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What does the F stand for in RTFM? :-DD
Formal, 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.
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What does the F stand for in RTFM? :-DD
:D I was curious whether there was an "unspoken convention" (as for the N=narrow dip) which is not always true, but it often is.
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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
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What does the F stand for in RTFM? :-DD
:D I was curious whether there was an "unspoken convention" (as for the N=narrow dip) which is not always true, but it often is.
Yeah, 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 for Texas Instruments parts around the time that the SN74xxx TTL logic family was first being produced and was loosely copied by some other manufacturers second sourcing 74 series TTL parts. Note all the qualifications in 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.
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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.
You 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.
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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.