LF357 substitute

[Detectorist#1]

Hi jakob leo,
It is absolutely impossible to use LT1055 for Delta Pulse metal detector! Typical "input voltage range" is from Vee+3V to Vcc-3V. For Delta Pulse MD this parameter have to include Vcc. Read datasheets more carefully.

[jakob leo]

Lt1055 est plus proche pour lf357n

[Detectorist#1]

Additional information for problem with LF357 for Delta Pulse MD. The company Texas Instruments continues to produce LF356 (July 2025) in convenient for DIY people DIP-8 case. In Delta Pulse MD the first delay is set in range 40-160us. For these relatively long delays, is possible to use LF356 (5MHz_12V-us) without problems. This not eliminates the problem with TYPICAL and WORST case of "common mode input voltage" range!

[Detectorist#1]

Many questions for this famous LF357. This OpAmp is used in wide copied Delta Pulse MD. Input voltage in this schematic for this OpAmp is equal to Vcc. According the datasheet, this is possible TYPICAL but NOT guaranteed. If your part haven't typical value of "input voltage range", maybe this part is not fake! This project is for DIY projects - not for serious manufacturing. Serious solution is to use OpAmp with rail-to-rail input voltage range in this project.

[nejdet]

Interesting... however, the footprint is I think TO-5 8pin, not DIP8. Therefore, it's not really suitable for integration into an existing layout. However, it would be fine for a new layout design. Is the production of this IC-chip still active? Because the datasheet looks already quite old style.

I have no idea! It works very well. A colleague in Sofia sells them at Bazar BG
https://bazar.bg/obiava-49502679/mab...-lf357-barz-ou

[GeoMax]

https://datasheet4u.com/datasheet/ETC/MAB357-771583
Schematically completely identical!
In Bulgaria it is available at a ridiculous price - 3 lv. / 1.5 euro

Interesting... however, the footprint is I think TO-5 8pin, not DIP8. Therefore, it's not really suitable for integration into an existing layout. However, it would be fine for a new layout design. Is the production of this IC-chip still active? Because the datasheet looks already quite old style.

[nejdet]

https://datasheet4u.com/datasheet/ETC/MAB357-771583
Schematically completely identical!
In Bulgaria it is available at a ridiculous price - 3 lv. / 1.5 euro

[kt315]

It is necessary to find a reputable supplier and choose second-hand disassembled parts

yup. you have to REORIENTIRE your request on - Who is very reliable seller in China we can buy the chips from. and to give us a link on the shop.

[Emersonpaz]

Genuíno Motorola LF357J I've already bought and used them in several detectors, they are great.

https://a.aliexpress.com/_mPS4ZHV

[jstcq.com]

why you do not use SEARCH before to ask? you see the matter LF357 is absent at first forum pages and thinking it was never.
tragical illusion. the forum had disputed billion times, NO ISSUE.
CHINESES DO JUST THE COUNTERFEIT. if you buy AD744 you will get TL071 remaked and so with every 'substitute'.

It is necessary to find a reputable supplier and choose second-hand disassembled parts

[kt315]

Where does your sense of superiority come from?

why you do not use SEARCH engine before to ask? you see the matter LF357 is absent at first forum pages and thinking it was never.
tragical illusion. the forum had disputed billion times, NO ISSUE.
CHINESES DO JUST THE COUNTERFEIT. if you buy AD744 you will get TL071 remaked and so with every 'substitute'.

[jstcq.com]

you are just beginner. i did keep the list from the forum. if you are not so happy in life it's the tragedy.

Thank you

[kt315]

MAB357

BOM file of DELTA PULSE. open and joy

[nejdet]

LF357 has been discontinued, what are its alternatives?

MAB357

[kt315]

The key indicators of an operational amplifier mainly include: supply voltage, input offset voltage, input offset current, open-loop gain, bandwidth, slew rate, common mode rejection ratio, power supply rejection ratio, input impedance, output impedance, noise density, and operating temperature range.
Comparing the slew rate and bandwidth, the solution you provided has sufficient slew rate, but the bandwidth is lower than LF357.
Thanks for your help.

you are just beginner. i did keep the list from the forum. if you are not so happy in life it's the tragedy.