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 Post subject: Fake Parts Rant Room
PostPosted: Tue Dec 20, 2022 2:12 pm 
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Joined: Mon Nov 23, 2020 1:39 pm
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Location: Vermont
I didn't find another thread or forum here on this topic so I made this one.

I *did* see a recent thread over in Troubleshooting that mentioned TL072CPs with code "18MDSHY" but didn't want to hijack it, so I'll say it here instead: Fake parts gives me a sad.

I have 20 TL072CPs with code 22ALE3M and as far as I am concerned they are not TL072s, judging by their slew rates (which are slower even than 741's). Slow isn't always bad--I have some weird tribulations with oscillators I was building that were fixed by including some slow op amps in the chain--but I don't want a colleague to expect TL072 performance if they find these hanging about. I've spent enough time with them, I don't feel like studying them enough to find out what they *really* are.

So to the highly-suspect code 18MDSHY (as reported here and elsewhere) I am adding 22ALE3M as something to be wary of. End of rant, for now.


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 Post subject: Re: Fake Parts Rant Room
PostPosted: Tue Dec 20, 2022 2:56 pm 
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Location: Albany, NY
Thx for the heads-up!

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 Post subject: Re: Fake Parts Rant Room
PostPosted: Tue Dec 20, 2022 4:46 pm 
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I find it hard to believe that they've started counterfeiting TL072. A lot of bad parts were manufactured during COVID....I guess it's still going on and maybe they are still making bad parts. But a lot of bad new production parts were pushed through QC and sent out into circulation. So it's not that they are "fake". Not like MN3005 for example where they sand off the original print from an MN3208 and reprint "MN3005" over it. They are just crap. And there are a bunch of them out there. It's going to be a while before all the junk COVID parts are out of circulation.

If you are in the States, only order semi-conductors from Mouser or Digikey for the time being.

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 Post subject: Re: Fake Parts Rant Room
PostPosted: Fri Jan 06, 2023 8:51 am 
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Location: Vermont
The vendor has supplied me with some replacement chips, which at least from the point of view of slew rate could in fact well be genuine TL072's. Here's a photo of the chips: On the left, a TL071 that had passed the slew rate test at least (12.5 V/microsec), and a recent replacement TL072 that also passes (17V/microsec); on the right, an example of the TL072 originally shipped that has a slew rate slower (0.4 V/microsec) than any of my varied 741's.

Attachment:
fake chips.jpeg
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 Post subject: Re: Fake Parts Rant Room
PostPosted: Fri Jan 06, 2023 1:50 pm 
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The two on the left have the Texas Instruments logo. The one on the right has the weird logo we've noticed as well on the defective TL072

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