How know when LM357 is original?...

[Rodelio]

How will know, in te case of LF357, when an operational amplifier is original. Help..

[Andi68]

So I look closely at the manufacturer's logo

http://www.ecadata.de/herst/myshowlogo.php?F_SPRACHE=1

[Rodelio]

Ok Andy. Thank for the tip.

[kt315]

if you buy on ali read/take attention negative feedbacks of guys from Russia, Ukraina, Belarusia. they know.
if you need tech device i gave a link on forum. in DP with o-scope 100 MHz band you can see a fitness but you would have original one
to compare.

[Rodelio]

I think that this LF356 is original one...

if you buy on ali read/take attention negative feedbacks of guys from Russia, Ukraina, Belarusia. they know.
if you need tech device i gave a link on forum. in DP with o-scope 100 MHz band you can see a fitness but you would have original one
to compare.

[Rodelio]

Thank for the tip kt315

[kt315]

[ATTACH]46823[/ATTACH]

logo does not say nothing now. chinese can stay any logo you ask. they did sell tm-808 with USA flag and whites logo, as an example.

[Andi68]

The logo for recognizing counterfeits is often referred to.
The kt315 recognizes this with his magical powers?

[Rodelio]

I have a friend traveling on Panama. He's seeking some LF357 for me. I hope hi get some luck. To many cheneese in this country

[Andi68]

On ebay com there are also some.
I ordered some in China and one in England.
I will test them in the circuit.
Possibly also the TLE2081 as a replacement type

[ivconic]

How to know....?
Good question!
If one don't have specially prepared testing equipment... tough to know and be sure, until you put it in circuitry and see the behavior.
I discovered fake TL071 chips very simply.
Previously during the years i made copies of one and the same "echo" module for hundred times.
So i know how it supposed to work and sound when microphone attached.
So when i put fake TL071; i could immediately tell the difference, because it was dramatic.
About LF357... how to know?
Previously made Delta Pulse, FelezJoo PI or any other similar detector will tell you if the chip is fake or not.
Record the behavior of original chip, make some measurements and write them down.
Than replace the chip and compare.
Another way to be sure is to buy those chips only from trusted and credible suppliers.

[Andi68]

Yes it is.
I have bought very cheap LF357 in china and an expensive one in England.
In the circuit I will test them.

[Rodelio]

here's some ic's from my stock. Now i wonder: What of them are original or fake.

[Rodelio]

i think that the LF?s at the right are original but i'm not sure...

[Andi68]

Have you already tested it?

A remote diagnosis can not be made