16 Jul
2013
16 Jul
'13
2:02 a.m.
On Mon, 15 Jul 2013, Chuck Guzis wrote:
On 07/15/2013 06:36 PM, Josh Dersch wrote:
It looks like a counterfeit part to me as well. The spacing of the
font/printing is wrong and it isn't as sharp as the genuine TI chips I
have here that have the later style of printing. Is there a country of
origin molded into the bottom of the IC? All of the TI chips I just looked
at have such markings. The plating on the leads of the ICs I compared is
also very very smooth and almost polished-like. FWIW, my money is on
Jameco since DigiKey is very very cautious where they source
semiconductors from.
I've put a picture up at:
http://yahozna.dyndns.org/scratch/imlac/fake7475-full.jpg
I was paranoid after you mentioned the "7574" thing that perhaps I had
gone insane (or become dyslexic) and had spent an hour last night
misreading a chip label, but no, it's clearly labeled as an SN7475N with
TI branding :).
Well, to my eye, it looks like no TI chip that I've ever seen. In my
plain-jane SN74xxx (not LS, S, etc.) collection from the 70s, the TI packages
that I have do not have pin 1 "dots", but the usual rectangular relief on the
pin 1 end. Your package looks more like a Motorola bug--particularly the
"fuzzy" pin 1 depression.
I believe you've got a forgery. On the clumsier forgeries, paint is applied
over the old marking and then the labeling. You might see if that's the case
with your chips. 