LM3886 fakes??

... I think faking an IC is a big and hard thing to do so I doubt it..

It may be hard to fabricate a counterfeit IC with the same specs as the original, but it's probably not that hard to take a lower-spec IC and re-package or re-mark it as a higher spec IC.

One could take a TDA series chipamp die like the TDA2050, add another die for the mute logic and package them together as a (fake) LM3886.

Alternatively, one could take an LM3876 and remark it as an LM3886 - even experts will be fooled.
 
I had a few (2) fake TDA1514 power chips.
The writing whas a bit different then from the original.
Allthough this is not the criteria for being a genuine or fake part.

Here is what happend:

After installation the chip lasted for about .1 second...
Used the second chip with current regulated power supply; draws excessive current on the negative side.
Bougth another from a reliable supplier in Germany; the unit works as supposed to be.
So I must conclude that your chips are fake.
I hope it's a one-off problem and not for all your chips. That would be bad, very bad.

The seller payed back the full amount of both chips.

If the price is cheap; take care...
Tarzan
 
They also acquire factory rejects and sell them... or they sell an empty package, looks like the real thing, but has no die in it so it doesnt work at all.

Sadly eBay is the main outlet for these things - not worth the risk any more, too bad as that's where I got mine for a good price.
 
Here's one I got off ebay; the defects are glaringly obvious...

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Two more possible clues:
- weight: 5grams (+/- 0.2grams) (uninsulated tab "T" version)
- appears the tab is copper with a tin/nickle/cad plating.

note:
- parts acquired 2007/2008.
- don't know if newer parts are "laser-imprinted," as opposed to "printed."
 

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Yup, the current batches (probably RoHS-compliant) have fine laser engraved markings, and an 8-digit batch code as opposed to the earlier 6-digit JMxxyy batch codes.

Another feature of the genuine parts is clean right-angled lead bends, as opposed to curving bends on some fakes.
 
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well for comparison here are a couple of pictures of my LM3886TF's I have no reason to suspect they are fake, they work fine :)

The leads on db!'s pic really look dodgy, even bichi's did at first (the profile shot shows them better) but I think it was just the camera angle.

Note that the second pic I have clipped off the NC leads since I was using them in a very tight P2P implementation.

IMG_0486.jpg

IMG_0487.jpg

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Tony.
 
I got some from a shady ebay seller (sigh) and just sent them back for a refund.

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the one on the far left is a known good (real brand) device. the other two on the right came from the same seller where I got the set of VERY fake blue trimmer pots from.

the trimmer pots, fwiw:

5230789958_5036809ea9_b.jpg


any parts you buy from ebay - assume they're fakes unless you KNOW otherwise. (deep sigh)
 
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My experience

I ordered a set of 4 LM3886TF from a Chinese seller via eBay and then saw the thread about fakes. Then I ordered samples of the same chip directly from National. I received both and they are identical, new laser etched serial numbers and everything. There is a minor difference in the casing between the chips that have V8 and U12 impressed into the small circle in the bottom right corner of the chip. I received both V8 and U12 chips from the factory and from the seller so I guess the china-man gave me the real deal.

Guess I'll have to solder them up to hear the potential difference but I'm an optimist and expect no difference.

eBay seller: "ordoer"

BTW, I once ordered a pair od LM4562 opamps from eBay to pimp my Marantz CD-Player...these were in fact fake, the output was noise/distortion and minor traces of music. Then I put in LME49720HA (I recommend these) I got directly from National and all was well, better than that

Cheers
 
Got some TDA2040s off of the 'bay. One had DC rail on the output. The others worked and sounded okay, but max output voltage swing was less than authentic parts. Also, they had no built in protections. I decided to get rid of the fakes, so I put them on a breadboard and fed them a signal and shorted the output. The fakes popped in a fraction of a second. I tried a known authentic one, and it would never blow after shorting for several seconds and trying several times.
 
Its too damn hard to find cheap original parts...
I bought set of components for stereo TDA1514A amplifier...
Well, the legs of the ic looked shiny, like there were brand new, they looked really good :O
But damn, no protection at all, of any kind!
Pushed both of them over the limit with output of 31V 2,11A! and one of them blew apart.