Repairing industrial hydraulic sequencer, many ST ULN2004A's, not sure if discontinued, helpful to know if worn out. How to arrive at date code from print top of plastic DIP ULN2004A GK651288 VW GK CHN is 1988 etc ?

[Niche]

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[Peter BENSCH]

Welcome, @Niche​, to the community!

Surprisingly, the ULN2004A is still in production. A quick search on the internet should bring some suppliers to light.

If the problem is solved, please mark this thread as answered by selecting Select as best, as also explained here. This will help other users find that answer faster.

Good luck!

/Peter

[Niche]

Yes I thought it might still be in production but, doesnt address the question which is

how do I arrive at the date of manufacture from the numbers printed on the DIP top ?

Looking forward to knowing date of manufacture from the coding information on the chip,

as its important for industrial equipment of this era as part of risk assessment management ie the conventional MTBF saddle curve etc.

From patterns on other ST devices and similar to other manufacturers it appears

as Week 51 of 1998 though with the preceding 6 maybe the factory, no of years since inception but, that doesnt matter - need the year of manufacture at least, thanks

Ah just noticed u are employee - great - please advise date ???

BTW: Would like to change the web site inserted nickname, cant see how to do that, any ideas ?

Mike

[Peter BENSCH]

Sorry, I had understood the question differently and interpreted it as a question about substitutes.

Anyway: the date code in this case can be found in the second line, 3...5th character and is read as YWW.

So in your example GK651288 => year ending with 6 (1996, 2006, 2016) and calender week 51. For a further narrowing of the decade, one would have to have the label of the packaging, but unfortunately it is not possible to determine this from the marking on the component.

The last three characters here code the internal number of the backend, so the 288 has nothing to do with the date.

Nickname - you can change it in your profile:

My Profile > Update my Profile > Nickname

Good luck!

/Peter