Fake MC12080 prescalers and LM4562 op amps from eBay (China) - Page 1
Forum section: electronics / general

author: brian_mk
author_rank: Regular Contributor
timestamp: August 05, 2020, 03:51:09 pm
content: Ok so maybe I was being stupid thinking that I could buy 5x MC12080 prescalers from China on eBay for £3.79.If I order from mouser uk I would pay £3.99 each plus £12 delivery.When I tested them, instead of dividing by 10,20,40 or 80 as determined by the S1,S2,S3 inputs, they divide by 2,4 or 8.I suspect they are MC12093 devices.A while ago I bought some LM4562 op amps from eBay. They turned out to have a GBW of about 4MHz instead of 55MHz.I suspect they were really TL072 or similar.I spent ages trying to figure out why my design did not work as expected.I'm getting really fed up with being sold fake crap from China.So I'm going to name and shame the sellers:-'hia5' sells fake LM4562.'gc_supermarket' sells fake MC12080.AVOID!

author: magic
author_rank: Super Contributor
timestamp: August 05, 2020, 08:33:04 pm
content: Welcome to planet Earth, friend. Everything on auction sites is fake unless you have good reasons to believe otherwise.(That being said, the fake LM4562 I have seen so far were NE5532, TL072 is disappointing.)

author: thm_w
author_rank: Super Contributor
timestamp: August 05, 2020, 08:54:36 pm
content: Any sort of premium opamp for cheap on ebay is almost guaranteed to be fake.Here are genuine LM4562 for 90c:https://lcsc.com/product-detail/General-Purpose-Amplifiers_Texas-Instruments_LM4562MAX-NOPB_Texas-Instruments-Texas-Instruments-LM4562MAX-NOPB_C57367.htmlOr its ~$2 from digikey.

author: Bud
author_rank: Super Contributor
timestamp: August 05, 2020, 09:24:08 pm
content: @op next time you need to buy a part, ask yourself a question :- is my time wasted on troubleshooting worth £12 delivery.

author: Bassman59
author_rank: Super Contributor
timestamp: August 05, 2020, 10:09:47 pm
content: Quote from: brian_mk on August 05, 2020, 03:51:09 pmWait, you're actually surprised that you got fake stuff for the impossible price?Oy.

author: MadTux
author_rank: Frequent Contributor
timestamp: August 05, 2020, 11:36:51 pm
content: What else to expect??? Don't buy anything of value from China on ebay, because it's 90% relabeled junk!Made that mistake with power mosfets, got relabeled junk salvaged from scrap yard.Same with GAL PLDs, everything with 24legs can be ground off and re-lasered as GAL20V8.Some sandpaper and a laser, $0.20 LM358 becomes $2 LM4562. And it will hard to tell the difference, unless you do some testing.

author: wraper
author_rank: Unknown
timestamp: August 05, 2020, 11:50:20 pm
content: Quote from: MadTux on August 05, 2020, 11:36:51 pmThat's some expensive shit. More like $0.02 opamp becomes LM4562.

author: SilverSolder
author_rank: Super Contributor
timestamp: August 07, 2020, 01:14:35 pm
content: I have experienced the fake cr@p from China via eBay feeling of disappointment... but only a relatively small percentage of the time. Most of the time, the parts I get have been genuine.I always check the "normal" distributors first - only if their prices are stupid (they aren't always) do I head for eBay.

author: wraper
author_rank: Unknown
timestamp: August 07, 2020, 01:24:21 pm
content: Quote from: SilverSolder on August 07, 2020, 01:14:35 pmMost likely you did not notice the difference in many cases. Not all parts are counterfeit but their amount and overall share is overwhelming.

author: magic
author_rank: Super Contributor
timestamp: August 07, 2020, 01:58:47 pm
content: I suspect that it's the "audiophool" and "hobbyist" parts which are faked the most, followed by obsolete parts which are likely to be recycled. Your chances are probably much better if you buy some obscure or specialized ICs that are still in production and pay reasonable price for them. OTOH for many beginners, particularly those shopping on price, fakes are virtually guaranteed.

author: SilverSolder
author_rank: Super Contributor
timestamp: August 07, 2020, 06:38:25 pm
content: Quote from: wraper on August 07, 2020, 01:24:21 pmIf you are familiar with the part, you are probably not so easily fooled as with an unfamiliar part.As a hobbyist, your trade-off is a lower price in return for a little testing... you can always get your money back if the item is fake.The worst example I've seen was a bunch of NPN transistors rebadged as JFETs. They couldn't possibly work in any circuit designed for a jfet...

author: wraper
author_rank: Unknown
timestamp: August 07, 2020, 06:56:20 pm
content: Quote from: SilverSolder on August 07, 2020, 06:38:25 pmLittle testing does not expose the vast majority of counterfeits, only the most blatant. Often you receive salvaged from e-waste and remarked stuff sold as new, rebadged to sell as better grade and whatnot crap you can only imagine.

author: SilverSolder
author_rank: Super Contributor
timestamp: August 07, 2020, 06:58:42 pm
content: Quote from: wraper on August 07, 2020, 06:56:20 pmFair enough, but if it works well enough to be acceptable by the hobbyist... it is like a placebo, makes the patient well?The latest research says that a placebo works,even if the patient knows it is a placebo!Personally, as long as the part tests well for my purposes, would I be OK with a recycled part with re-welded pins etc. in return for saving significant $$$? - Maybe.... It would of course be more honest of the seller to list such items as "Refurbished" rather than "New".

author: magic
author_rank: Super Contributor
timestamp: August 07, 2020, 07:53:41 pm
content: Quote from: SilverSolder on August 07, 2020, 06:58:42 pmExactly. The audiophile is happy because his new LM4562 sounds better than the TL072 it upgraded, the Chinese guys is happy because he made some money harvesting that TL072 from scrap PCBs and the environment is happy because the IC didn't end up in a landfill. Win win

author: thm_w
author_rank: Super Contributor
timestamp: August 07, 2020, 09:28:47 pm
content: Quote from: wraper on August 07, 2020, 06:56:20 pmI would estimate 99% of IC's that end up in e-waste are completely functional. If they can be safely recovered, they will be fine.Of course if they are remarked or advertised as new, that is an issue.Quote from: SilverSolder on August 07, 2020, 06:58:42 pmThere are a few sellers that are honest like this but its not many on ebay I know of.

author: floobydust
author_rank: Super Contributor
timestamp: August 07, 2020, 09:34:05 pm
content: It can be worse. I boughtOPA627for use in audio DACs, off eBay and Aliexpress. The IC's have very low distortion and work fine, although they will RF oscillate if you go near the offset trim pins, which I think strange. Non-vanilla op-amp prices are just obscene.OP627 $25 DigikeyOP627 $4 eBayAD744 $8 DigikeyAD744 $2 eBayAD797 $11 DigikeyAD797 $3 eBayApparently one possibility with OPA627 knockoffs are some other Burr Brown part or AD744 according toZeptobarsdie shots. So I purchased legit AD744 but no RF oscillations at the offset pins, but they do have different sound, a different IC.So I have no idea what IC's I've actually got

author: wraper
author_rank: Unknown
timestamp: August 07, 2020, 09:53:11 pm
content: Quote from: floobydust on August 07, 2020, 09:34:05 pmNone of them are even possibly genuine so savings are non-existent.OPA627 for $13-16 depending on quantity.https://lcsc.com/product-detail/Precision-OpAmps_Texas-Instruments_OPA627AU-2K5_Texas-Instruments-Texas-Instruments-OPA627AU-2K5_C22061.htmlEbay and aliexpress are not worth even trying for any opamps.

author: magic
author_rank: Super Contributor
timestamp: August 07, 2020, 10:03:15 pm
content: Quote from: floobydust on August 07, 2020, 09:34:05 pmTest things like quiescent current, offset voltage, noise, input bias current (is it FET or BJT to begin with?), GBW (shows up as a knee on noise measurements at high gain), slew rate...Even if you can't identify them, at least you will have some clue if they are any good.What if they are real 627

author: floobydust
author_rank: Super Contributor
timestamp: August 07, 2020, 10:48:49 pm
content: They could be genuine, we have no idea where the silicon fab is done for these parts. Packaging, font etc. looks like the usual low grade though. I would expect them to be rejects, overruns or untrimmed.USD $25 for a single op-amp, $50 for a stereo pair from Digikey, OUCH! $37 for DIP-8.Fake audiophile opamps: OPA627 (AD744?!)

author: Red Squirrel
author_rank: Super Contributor
timestamp: August 08, 2020, 03:07:47 am
content: I don't bother at all with Ebay, Amazon etc for parts anymore. Digikey is cheap enough in general and at least I get genuine parts. Basically I feel the piece of mind is worth whatever extra it may cost compared to some deal on Ebay. I havesomeAmazon parts in my bins like resistors and capacitors but those you can go less wrong, if you don't care too much about specific ratings. (ex: non production stuff and just playing around) Typically that stuff is just to pad an order to get free shipping.

author: BravoV
author_rank: Super Contributor
timestamp: August 08, 2020, 03:42:57 am
content: Quite boring reading this kinda whines everytimes ... a typical noob online shopper.

author: magic
author_rank: Super Contributor
timestamp: August 08, 2020, 06:21:50 am
content: Quote from: floobydust on August 07, 2020, 10:48:49 pmEverybody talks about "possible rejects", nobody has ever demonstrated evidence that it happensIME fake opamps are either completely different parts which don't even come close to meeting the specs or obviously recycled (stains, scratches, shiny non-PbF lead finish, false markings or genuine markings and random date codes in a lot).

author: floobydust
author_rank: Super Contributor
timestamp: August 09, 2020, 06:05:18 am
content: Where do you think the dies go that work but fail specs? Even in the 1970's they ended up packaged and sold, although widely known at the surplus houses. Nothing goes to waste in china.I couldn't test all the specs of an op-amp, that's a lot of work. Russians are measuring pin capacitance as a test for counterfeit BJT's and IC's.I usually encounter fake IC's that do absolutely nothing, as if there's no silicon inside.

author: magic
author_rank: Super Contributor
timestamp: August 09, 2020, 08:16:44 am
content: Heh, I knew people who interned at an IC shop and took failed dice as souvenirs but they had to sign a declaration that they will never resell them to anyone. The rest was destroyed.I suppose there is a chance of "leaks" and I don't know where they go, but most of the fakes on auction sites aren't them. If they exist, nobody has found and positively identified one so far, to the best of my knowledge.

author: SilverSolder
author_rank: Super Contributor
timestamp: August 10, 2020, 07:46:57 pm
content: Quote from: floobydust on August 09, 2020, 06:05:18 amI guess the less than honest seller hopes you will put it straight into inventory and not discover the issue until enough time has passed that they cannot reasonably be blamed...

author: db6178
author_rank: Newbie
timestamp: November 15, 2021, 11:20:10 pm
content: 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.

author: thm_w
author_rank: Super Contributor
timestamp: November 15, 2021, 11:31:32 pm
content: Quote from: db6178 on November 15, 2021, 11:20:10 pmDigikey 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.

author: Mecanix
author_rank: Frequent Contributor
timestamp: November 15, 2021, 11:36:21 pm
content: If the product is not advertised as "genuine" or "import" and inexpensive they are most likely domestic parts. Fortunately the sellers are honest about itwhen askedprivately 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.

author: magic
author_rank: Super Contributor
timestamp: November 16, 2021, 12:09:43 am
content: Quote from: db6178 on November 15, 2021, 11:20:10 pmI 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.