Today many higher-end controllers designed for motor and power control applications also have Op Amps as a device module to condition signals with signal routing done internally. The specs are fine for general usage.


http://ww1.microchip.com/downloads/cn/DeviceDoc/cn597782.pdf

 

for an amazon / ebay / AliX style search, here is an example
https://www.aliexpress.com/wholesale?SearchText=741+op+amp

that uA741 from TI is still around, it doesn't seem to be in short supply.
Then AliX vendors list lots of them, the risk is that they may literally give you an 'equivalent' for the part number you wanted

Even LM741 op amps are faked

 

With reference to application, etc ... the 741 was a "general purpose" op amp...
suitable for a broad range of applications including ...
- Comparators
- Multivibrators
- DC Amplifiers
- Summing Amplifiers
- Integrator or Differentiators
- Active Filters

So, the question was ...
What "modern day" Op Amps are a good "general purpose" substitute for the 741...
with equal or better spec's...
while, in particular, retaining a unit low unit cost.

There is no specific application at hand here at the moment.
I just wanted to find out some available "General Purpose" Op Amps to use instead of the 741.

From the thread I collected the following alternative parts which I'm evaluating ...
CA3240 - expensive at ~$3 to $6 each
op07 ~ $1 each - one per pkg
LMV358 ~$1 each - single 5v supply - two per pkg
LM358 ~$1 each - dual supply up to 32v with single supply output
LF356 - $1 each - one per pkg
LMR series including ...
LMR341G - ~60 cents each - one per pkg

I haven't fully researched these yet so any additional comments welcome.
Also, any additional parts that should be considered?

Thanks to all for comments and suggestions.

 

LM358 ~$1 each - dual supply up to 32v with single supply output

You can get LM358 at Tayda Electronics for $0.24 each. The quad version, LM324, is $0.29.

It's a single supply opamp. If you use it with dual supplies, you can have bipolar output. To minimize crossover distortion, have a constant load to the negative supply.

Avoid using opamps as comparators or comparators as opamps.

 

LM741 is an antique GP op-amp that has been around for a very long time and is used as a typical op-amp in the majority of electronics courses. It is not usually recommended for new designs.

If you are looking for an exact pin-for-pin replacement then you have to look at power supply requirements as well as pin functions.

TL071 and TL081 are good substitutions though these are JFET input op-amps.





Reference: https://www.petervis.com/Education/...ps/741_Pin_Compatible_Equivalent_Op_Amps.html

For new designs, every other factor comes into consideration - including power supply restrictions, single/dual/quad op-amp, and IC packaging. Hence there is no "one size fits all" solution.

Hence the proper answer is: if you are looking at a circuit or a design that calls for a 741 op-amp, or any op-amp, forget the 741 and study the topology, requirements and application of the circuit and select the op-amp accordingly.

Study op-amp basics instead.





An ideal op-amp has ideal properties.

The whole rationale for inventing and applying operational amplifiers is that the circuit designer can treat the op-amp as a black box and does not need to know about the internal design and limitations of the black box. The circuit behaviour is entirely a function of all components external to the op-amp. In real life, practice deviates from theory and the devil is in the details.

 

These are single supply op amps, I'd mainly use them for interfacing ADCs as buffers and sometimes for its amplification.

How many op-amps that you need in your circuit?
How many bits of the ADC(which ADC)?
Do you have a circuit or block diagram?
If you provide more info then our members can choose a better one for you.

If you only need one op-amp then you can choose LF356, I used it with an ADC or DAC about 5 years ago, that was an industrial project for a friend, if you need 2 op-amps or more then using LM324 is a good choice compared with 741 and it's cheap, 4 op-amps in one package.

 

How many op-amps that you need in your circuit?
How many bits of the ADC(which ADC)?
Do you have a circuit or block diagram?
If you provide more info then our members can choose a better one for you.

If you only need one op-amp then you can choose LF356, I used it with an ADC or DAC about 5 years ago, that was an industrial project for a friend, if you need 2 op-amps or more then using LM324 is a good choice compared with 741 and it's cheap, 4 op-amps in one package.

this is a common way I (ab)used my op amps as ADC buffers

https://www.allaboutcircuits.com/textbook/semiconductors/chpt-8/negative-feedback/
Those works well with lmv358 as a front stage to the ADCs for sources that can only provide milliamps or micro-amps.
And to an extent it 'protects' the adc / mcu in overvoltage situations. damaging the adc in the mcu pretty much destroys the mcu. while lmv358 is a separate part.

I've thought about using lmv358 to measure currents, it works but only on the low side.
High side i.e. directly from the power supply is 'impossible' and it takes special chips such as an
INA169 to do that. I've not figured out a cheaper or better way to measure currents on the high side with 'general purpose' op amps. those specific designed current measurement chips are actually competitive and designed for purpose, very hard to beat with any sort of discrete circuits
for current sense, I stumbled into an interesting article
https://www.edn.com/sensing-current-on-the-high-side/
^ that 2nd circuit which uses the +ve rail as reference, LM358 still can't be used for high side current sense, because LM358 isn't rail to rail.
maybe the 741s would do it.

I think i found my discrete high side current sense method
https://www.edn.com/circuit-senses-high-side-current/
https://www.edn.com/scheme-provides-high-side-current-sensing-for-white-led-drivers/
These are nice designs, apparently it takes a current mirror to do it, that simple 'general purpose' LM358 is not enough alone to do that.
combined with a current mirror, perhaps it could do it for high side current measurements.

 

Hi, you can see some options here: https://www.petervis.com/Education/...ps/741_Pin_Compatible_Equivalent_Op_Amps.html