LM3886TF version question

[emerth]

This is a question about the markings on LM3886TF chips.

I am looking at LM3886TF chips on ebay. The photos show NS cases, marked with two strings: "LM3886TF" in all cases; and then a second string which varies: "PM79AK", or "JM17AFE3", or "PM35AF".

The second string (the one that is not "LM3886TF"), might indicate production run or something else.

My question is does anyone know what that second string means and where I might find docs or discussion of the merits of one chip version over the other.

--

My question is motivated from that in the CPU world there have been times when a particular run of a CPU model was a superior over-clocker or had exceptional power consumption behaviour.

Perhaps this second string printed on the LM3886TF case carries info of a similar nature?

 

[AndrewT]

That second string could be useful in identifying a fake.

 

[TonyTecson]

no such thing as overclocking in audio chips....

there are two case types, TF ussually means totally encapsulated device...just the T means the heatsink tab is not encapsulated.

 

[tommy55]

may be helpful
National Semiconductor

 

[emerth]

may be helpful
National Semiconductor

Thanks Tommy.

I'd looked at National's site but not found that info.

 

[tommy55]

hi emerth
click at National Semiconductor (blue letter), it will link to National Semiconductor

 

[tommy55]

when i type this link w-ww.chipdocs.com/manufacturers/NSC.html#df, it will become the words "National Semiconductor" in blue. so you will go to that webpage directly (but without - between w-ww) or click at that words.

 

[JMFahey]

Those are Lot manufacturing codes, to help trace possible quality issues to the actual source, instead of wondering "who the @#~€¬"·$%& made this cr*p?"
This is one example of a full label, as printed on the cardboard box:

An externally hosted image should be here but it was not working when we last tested it.

Of course you don't have that much space on the component, so it gets a much simplified version.

For an *incredible* investigative work, read:
http://www.avnet-logistics.eu/fileadmin/user_upload/Date_Code_Collection/AL_DC_collection.xls

Personally, I'd download it and have it available for future use.

As of fakers, they can *print* whatever they want, can't they