General > General Technical Chat
Why is the 741 op amp still produced?
Kleinstein:
There are still a few circuits a round that are made for the 741. There is a lab supply kit (often from China) with TL081 OPs tortured with too much supply because the original circuit was made for the 741 that can stand a higher supply.
For a slightly improved version of the LM358 with less cross over distortion, there is the MC33172 - faster and less distortion, but otherwise similar.
The 741 was just so popular that there is still some demand and it is no magic in making them, even though they are not the cheapest to make and the supply current is rather high for the performance.
Rick Law:
There are posts about "right to repair" now and again. Right to repair means nothing if parts are not available. So from that perspective, the longer they can keep making that same something, the better it is for the consumer.
Rah_H:
741 are used in analog function generators. I have a MCP SG1639A 3MHz Analog Function Generator/Counter which has multiple 741s in it complete with IC socket. Old school ICs are still used in a lot of Chinese lab equipment because they are proven to work and are profitable. It doesn't matter if the technology is 30 years old, it is going to serve someone's purpose. So why change it?
floobydust:
It's gotten ridiculous that semi manufacturers optimize one or two things, roll out a new part number. Do we really need 5,000 different op-amps and the hours spent looking at datasheets to find the best part- which ends up being massively overpriced kills the BOM cost, or has long lead-times.
Why is a LM358 $0.15 but a better part over 10x the cost? Do they have more gold-pressed latinum inside?
An op-amp that has true competition has a reasonable price. Multiple-sourced 741, 358, 4558 is also why they are still alive.
Kleinstein:
One problem leading to so many OP variants is that they often behave different in the details. There are quite a few parameters to look at and not always is there a clear better or worse. There are cases when one wants some input bias current (especially a defined sign and order of magnitude). Also faster is not always better.
So the problem is that there is usually no 100% replacement / upgrade. Even if it works in 99.9% of cases it can't replace the original. There are plenty of OP versions that are not really needed any more: e.g. TL082 if there are TL072 (tighter noise specs) at essentially the same price and sometimes even cheaper.
With the serious distributors they even make a difference between the same part from different source (e.g. 741 or LM358 from several vendors with essentially identical specs).
Usually one has a few personal favorites in the head / drawer, so one knows if they are sufficient. One may later change to a more suitable/specific OP (e.g. lower cost), but one may also skip that step. The 741 is likely still in some peoples favorites / known by hart list. So even if not the best part it is still used. The best 741 substitute is probably still a 741 from a different source.
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