LF357 substitude

[6666]

we use LF356 in our board XR-71

Sinko1 what characteristics of the LF356 convinced you to use it in your project ?

[6666]

There are legit component suppliers even in China, buy from big distributors and not from aliexpress or ebay.

examples: cogobuy, allchips

The most important thing is the purpose for LF357, not knowing the circuit it’s hard to say what replacement is good.

allchips has no stock of lf357, cogobuy has no stock, next suggestion ?

[6666]

I have bought 5 LF357 so far and all are fake. Nothing shows this by looking at Chip package, but when we put it inside the circuit it does not work properly, then we realize it is fake. it seems they are other opamps such as 741.

Can you name the seller who sold you the fake chips so nobody else gets ripped off thanks
http://www.geotech1.com/forums/showt...-and-name-them

[jinbiao]

I bought no less than 100 LF357 / LF357M from different merchants in Alibaba. No fakes, everything is normal. Very cheap.WAY？？？

[jinbiao]

All parts come from Alibaba, everything is ok, no problem.

[bernte_one]

solution is not to search for old obsolete Chips, the Goal ist to redesign the circuits so that modern part can be insert

biggest Problem for most is that they can not read datasheets or at least the pinout configuration

maybe we can look for another chip than lf357 pinout compatible

another way could be to use an Adapter socket if circuits can not be updated for modern Chips pinout

[waltr]

solution is not to search for old obsolete Chips, the Goal ist to redesign the circuits so that modern part can be insert

biggest Problem for most is that they can not read datasheets or at least the pinout configuration

maybe we can look for another chip than lf357 pinout compatible

another way could be to use an Adapter socket if circuits can not be updated for modern Chips pinout

As I post above:
Check the LF411.

And one can Use the product parameter searches in DigiKey & Mouser to find compatible chips without buying from them.

Here is a parameter search in DigiKey. Lots of aop amp to check.
https://www.digikey.com/products/en/...=1&pageSize=25

[kt315]

read this thread at first http://www.geotech1.com/forums/showt...ash-technology

do not buy nothing new. all projects you see here do not need in new chips. take chips from trash WITHOUT MONEY WASTE.
i take TLE TEA LM TL opamps from old boards. open any old CD ROM drive or old Hard Disc you will see them much.
i set TL081 and it works. WORKS.
oldest boards has ONLY original chips and all NOT fake.
all my projects use ONLY the trash chips -! i do projects for poorest people layers in the world. THE Folks' Projects.

[homefire]

The LF357 is really quite a Generic Op Amp these days. Most any modern JFET Op Amp with the same power requirements and pin out would do the job I would think.

http://www.physics.wisc.edu/undergra...F357-opamp.pdf

[qute1]

I hear this KT315 the world needs wombles i too am a womble and agree implicitly i scour charity shops and markets for older tech (audio amps very rich in opamps) it is rare to get bad chips as they worked in the first place and their MTBF is not even close. So much waste in the world remember if i doubt "womble" it.

read this thread at first http://www.geotech1.com/forums/showt...ash-technology

do not buy nothing new. all projects you see here do not need in new chips. take chips from trash WITHOUT MONEY WASTE.
i take TLE TEA LM TL opamps from old boards. open any old CD ROM drive or old Hard Disc you will see them much.
i set TL081 and it works. WORKS.
oldest boards has ONLY original chips and all NOT fake.
all my projects use ONLY the trash chips -! i do projects for poorest people layers in the world. THE Folks' Projects.

[kt315]

;248107]I hear this KT315 the world needs wombles i too am a womble and agree implicitly i scour charity shops and markets for older tech (audio amps very rich in opamps) it is rare to get bad chips as they worked in the first place and their MTBF is not even close. So much waste in the world remember if i doubt "womble" it.


[/QUOTE]

[rickb]

If you cannot get what you want, and it is a standard pin configuration, put a socket on the board and use what you have until you get what you need. (apologies to mick)

[Andi68]

What is the real problem now?

There are at least one dealer here in Germany where almost every old semiconductor can be found

[kt315]

i think Iran has to reforward a part of all electronics trash going in Afric on his territory. somebody must organize dismantling of the boards and release up the components in a retail net shops.

[qute1]

Oh dear it looks like you are right about the AD797 my apologies i was just looking for something he might be able to get more easily.

look that https://www.eevblog.com/forum/projec...t-dosn%27t!!!/