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| Fake MC12080 prescalers and LM4562 op amps from eBay (China) |
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| db6178:
Definitely not worth saving a couple bucks on the off chance those aliexpress-sourced chips aren't fake. Unless you're looking for decades-old discontinued components that were once commonplace in years gone by (and even then ) stick with the well-known suppliers like DigiKey, Farnell, etc. I orderdered 10 x LM4562P, at a fairly normal price other than cheaper shipping. Now, half a year later, I been waving the things all over the place till I was black in the face, but couldn't get better than 2V/us slew rate out of them. Turns out they are fake. I guess I juist gotta throw them. More and more I realize just how much of the electrionics components I bought from AE over the years are either fakes or just no-name utter and useless junk. I wasted a full day before concluding with certainty these particular LM4562P op amps were fake. See photo. My guess is, based on the residual marking poking out from under the counterfeit blacktopping, is that they started iout as 5532P rejects, cuz they don't even match those specs. |
| thm_w:
--- Quote from: db6178 on November 15, 2021, 11:20:10 pm ---Definitely not worth saving a couple bucks on the off chance those aliexpress-sourced chips aren't fake. Unless you're looking for decades-old discontinued components that were once commonplace in years gone by (and even then ) stick with the well-known suppliers like DigiKey, Farnell, etc. I orderdered 10 x LM4562P, at a fairly normal price other than cheaper shipping. Now, half a year later, I been waving the things all over the place till I was black in the face, but couldn't get better than 2V/us slew rate out of them. Turns out they are fake. I guess I juist gotta throw them. More and more I realize just how much of the electrionics components I bought from AE over the years are either fakes or just no-name utter and useless junk. I wasted a full day before concluding with certainty these particular LM4562P op amps were fake. See photo. My guess is, based on the residual marking poking out from under the counterfeit blacktopping, is that they started iout as 5532P rejects, cuz they don't even match those specs. (Attachment Link) --- End quote --- Digikey has 8DIP in stock. The first test you should do with suspected fake opamps is slew rate, simple unity gain circuit. There are probably other tests but that should catch most fakes, as they are usually LM358 or whatever dies. |
| Mecanix:
If the product is not advertised as "genuine" or "import" and inexpensive they are most likely domestic parts. Fortunately the sellers are honest about it when asked privately via PM prior purchasing. On the domestic ecommerce however (e.g. taobao.com) they are all advertised correctly though, the origin is clearly id as domestic, or genuine/import so you know what you are getting yourself into from the start. |
| magic:
--- Quote from: db6178 on November 15, 2021, 11:20:10 pm ---I wasted a full day before concluding with certainty these particular LM4562P op amps were fake. See photo. My guess is, based on the residual marking poking out from under the counterfeit blacktopping, is that they started iout as 5532P rejects, cuz they don't even match those specs. --- End quote --- I have no explanation for the apparent "xxx32P" marking on the bottom left chip, but the shape of the package doesn't look like any 5532 I'm aware of and I have seen a few (Philips, Signetics, TI, ON, JRC, Samsung). And 5532 is faster than 2V/µs. Check with a DMM is there are diodes both ways between IN+/IN-. Such diodes would be present in either LM4562 or NE5532, but absent in RC4558 which I presume those ICs really are. |
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