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OK, so the uA741 is 42 years old now. For its time it may have been a great opamp; the requirements weren't as high as today, and there was far less competition. But I was wondering what's the 741's appeal today.

  • it's slow. GBW 1MHz, slew rate < 0.5 V/us
  • it's not low power, nor low voltage
  • it doesn't have low bias current FET inputs
  • it doesn't have rail-to-rail inputs or outputs
  • it's not low noise
  • many more modern opamps have comparable price

Why is the 741 still used today?

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  • 4
    \$\begingroup\$ My guess: inertia. \$\endgroup\$ – drxzcl Nov 10 '11 at 21:12
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    \$\begingroup\$ If the application doesn't require high speed or low power, and isn't especially sensitive to noise, is there any reason why I shouldn't use a 741? \$\endgroup\$ – Rory Alsop Nov 6 '12 at 12:48
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It's an ideal op amp to learn the basics on due to its non-ideal nature. The first thing we learn is infinite input impedance, infinite gain, as well as a few other silly things. The 741 obeys none of these idealities, forcing students to learn the hard way how to cope. They see bandwidth limitations without using expensive oscillators or function generators; they see early saturation, nowhere near the rails, allowing the use of cheap multimeters. Many textbooks use the 741 as an example due to its ubiquitous availability and simple verification of non-idealities.

Today, we can buy op-amps with mV offset and noise, 100s MHz bandwidth, nA leakage, etc.. One of the most time consuming part of a design is looking for parts, especially for the inexperienced. Academics aren't experienced design engineers, and will use the parts they know, as they have better things to do than look for parts (like write that grant application, right? :). This outdated part therefor gets introduced into new designs from copying legacy modular designs, and familiarity from instruction.

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    \$\begingroup\$ "It's an ideal op amp to learn the basics on due to its non-ideal nature." That's fine in an academic environment, but in a commercial enterprise it's cost-efficiency and risk reduction that count. Better specs may help reducing design risks. \$\endgroup\$ – stevenvh Dec 24 '10 at 17:29
  • \$\begingroup\$ I agree with you on that. It's a relatively simple chip where you will be able to see where practical parts leave theory. If you want a lab test and get a 100MHz GBW opamp, you would need incredible high frequent signals to show the problem of bandwidth. Or things like slew rate etc. Furthermore, the NE555 is also still used widely today. It's a timer IC which will be outperformed in many ways by other ICs, but still it's a very useful bit of kit. Same for Lm311. If it's 'good enough' and cheapest way to do, then do it. \$\endgroup\$ – Hans Dec 24 '10 at 18:09
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    \$\begingroup\$ @Hans: I don't think you can compare the 555 with the evolution in opamps. Over time the 555 has seen few variants, I can only think of the CMOS version 7555, which improves on power consumption. IMO there's little else you can change. OTOH there are hundreds of opamps which can be a direct replacement for the 741 in certain designs. \$\endgroup\$ – stevenvh Dec 24 '10 at 19:51
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    \$\begingroup\$ The thing is, nobody seems to mention, in the instructional settings where the 741 is introduced, that it is a lousy op-amp with much better alternatives that are just as inexpensive. Therefore people keep using the damn things in real designs. \$\endgroup\$ – Jason S Nov 9 '11 at 12:31
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    \$\begingroup\$ Hey @CalebReister, search Digikey under Integrated Circuits > Linear - Amplifiers - Instrumentation, OP Amps..., then filter by your requirements. (E.g. I pulled the MCP6281 for general use and low cost.) Otherwise, TI has 3 direct replacements on their LM741 site, of which the LM7301 looks pretty great. \$\endgroup\$ – tyblu Apr 11 '17 at 18:21
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Many old designs are still around. Plus, some positives are

1) It is readily available from multiple sources (ST, TI, National) which (having multiple sources) can be a big issue for certain industries.

2) It has been around for a while, is well understand, reliable, and will most likely will continual to be available for a while, again, very important for long life applications.

3) It has a large voltage range, many newer op-amps don't.

4) Output short circuit protection.

5) It's slow. This is good for many applications. Why is faster always better? Having an overly fast op-amp just increases susceptibility to noise.

6) Many people know it and use it, there's something to be said about not having to evaluate, test, etc., a new chip, as well as not having to stock a new part.

7) It doesn't have FET inputs. There are pros and cons to such inputs. Certain designs may be better with them.

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    \$\begingroup\$ I have to disagree with some of these points, though. 1.) Amplifiers like TL081, LM358, etc. are all available from many suppliers and 4.) I don't know of any modern non-power op-amp without short circuit protection. Could you point out one? \$\endgroup\$ – Thomas O Dec 24 '10 at 18:51
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    \$\begingroup\$ -1: There are better alternative opamps for every single one of your points. I take issue with a few things, too: #2 -- the 741 is not reliable because it suffers from phase reversal if you use it with input voltages close to the positive rail. #6 -- that's just lazy. It's an op-amp; if you understand the datasheet for one part, you can understand how to use just about any opamp. \$\endgroup\$ – Jason S Nov 9 '11 at 12:34
  • \$\begingroup\$ +1 - A "universal" part that's well used, well understood, well supported, and widely available has a lot going for it in all sorts of applications. It's kinda the electronics equivalent of standard nuts & bolts. You only use weird things if you have to. \$\endgroup\$ – John U Mar 21 '14 at 16:00
  • \$\begingroup\$ An enormous disadvantage of it is that many of its important properties are not even characterized in the datasheet. For example, since you mentioned it has BJT inputs, I decided to compare its input noise voltage to the TL071. However, the 741 is not even characterized for noise. The only vague (non-academic) advantage of it that I can see is that it is the only common opamp still widely available in a ceramic package. This is of course a very dubious advantage anyway but could arguably be useful in some cases. \$\endgroup\$ – Oleksandr R. Apr 7 '15 at 23:23
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Is it really used per se, or simply kept around for legacy designs? Changing an op-amp in an application where those specific parameters are important (i.e. feedback loops) can be problematic at best (or outright dangerous at worst) - best to let sleeping dogs lie in these situations, sometimes...

I can speak to the fact that in both of my career stops thus far, there haven't been any new designs that I've seen or touched using the 741. For me, the LM358/LM324 is the 'go-to' part where things like input offset voltage or rail-to-rail capabilities aren't critical. It's well understood, it 'works', and it's cheap.

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    \$\begingroup\$ I don't recall ever seeing a 741 in an actual production device that couldn't easily be labeled "vintage". I have seen 741's as/in teaching tools and kits, though. \$\endgroup\$ – XTL Jan 3 '11 at 20:04
  • \$\begingroup\$ @XTL: Almost... The RC4558, basically a dual 741 without the extra pins for offset compensation, is still used in recent designs of consumer audio equipment like output buffers for CD/DVD players and the like. I guess the reason is that it's inexpensive, bust-proof and available from multiple sources. \$\endgroup\$ – zebonaut Nov 9 '11 at 10:58
  • \$\begingroup\$ When I took apart my cheap multimeter after it died (I wanted to salvage the piezo beeper and the 9V connector ;) I was surprised to find a single 741 lurking in there. \$\endgroup\$ – drxzcl Nov 10 '11 at 21:11
  • \$\begingroup\$ thanks for naming alternatives. \$\endgroup\$ – WeGoToMars May 6 at 12:50
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In many cases I've seen in online electronics forums, the 741 is designed in by beginners who just don't know of any other opamps. They may have read about it in a textbook or seen it in another old design and assumed it was a reasonable choice. Once they learn that LM324, etc. is readily available, cheap and easier to use, they'll normally switch.

The other big reason already stated is legacy designs. Something works, is still in production, and there's no compelling reason to change it. If you've been selling a product for 30 years and you won't run out of parts, and you won't make any more money by changing to a newer opamp, they why change?

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My guess: people tend to stick with what they know. If you've learned the errata and gotchas of the 741 and it works for your application you'll use it rather than learn something new for no reason. Also, my guess is that many applications don't require terribly high performance, so the 741 works just fine.

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