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Why is the 741 op amp still produced?

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Wolfgang:

--- Quote from: peter-h on September 21, 2020, 08:49:40 pm ---One would not design-in a 741 today, or anytime since about 1975, but it would be wrong to say the LM358 (which I've been using since c. 1975) replaces the 741 because - for a start - the output voltage swing is very different.

There are rail to rail (on both input and output) op-amps but they are quite expensive. I have just done a design which needs to achieve 16 bit DC precision and a lot of the op-amps cost around $2 each.

As a general comment, the world has moved many years ago from generic (and cheap, multi sourced) parts to high performance (and expensive, single sourced) parts. A clever designer will use the former, and they still exist. A lazy designer will use the latter, and keeps firms like Linear Technology in business :)

--- End quote ---

I would agree that the 358s/324s cannot replace the 741s in case crossover distortion is a big issue, but in other cases the advantages are obvious:
- 2/4 instead of one in a single case
- more current
- negative rail included in input and output, thats often enough.
- cheaper
- slightly faster
- lower voltage operation possible (>2.5V)

So, 741 for repair/replace/legacy systems business - why not. New stuff ? Never.

Tomorokoshi:
Let's just say that I made the mistake of using op-amps from Microchip. Once.

james_s:

--- Quote from: Tomorokoshi on September 21, 2020, 09:26:00 pm ---Let's just say that I made the mistake of using op-amps from Microchip. Once.

--- End quote ---

I've used them a few times, they worked fine, it was very non-critical applications though. Curious what problems you experienced?

coppice:

--- Quote from: Circlotron on September 18, 2020, 10:49:46 pm ---The 741 might have been a big deal in its day, but things have moved on. Nowadays we have a zillion different op amps to choose from, ranging from similar to vastly improved performance. I can’t remember the last time I saw one in a piece of equipment. And no one with a grip on reality designs them into new products. And even in the case of repairs for old equipment there would surely be modern substitutes available. And get this - I was looking at the TI 741 data sheet and it says the 741 “feature(s) improved performance over industry standards like the LM709.” The LM709 might indeed have been an industry standard fifty years ago but it’s a bit of a stretch to still refer to it as that. We’re in the age of GPUs with 28.3 *billion* transistors. It’s time the 741 was put to bed. It’s fine to read all about it from a historical point of view. That great, but I think school textbooks should stop using it as an example as if it were a mainstream device. But what to replace it with? Over to you.

--- End quote ---
The world needs a lot of simple glue chips to sit between the big chips. Time was when 2 input gates only came in packs of 4. These days you can buy a small pack with just one gate in it, responding to the common modern need for just a single gate here and there as glue between complex chips. Billions and billions of simple low performance op-amps are used each year. However, if you ask someone at TI to recommend a simple low performance cheap op-amp they'll probably recommend an LMV321, or an LMV324 is you need several amps. Note than the LM321 is about as old as the 741, but most people use the more flexible LMV321 derivative these days. Nobody recommends a 741 any more, but a lot are still used in equipment whose design hasn't changed for decades.

Zero999:

--- Quote from: coppice on September 21, 2020, 10:00:41 pm --- However, if you ask someone at TI to recommend a simple low performance cheap op-amp they'll probably recommend an LMV321, or an LMV324 is you need several amps. Note than the LM321 is about as old as the 741, but most people use the more flexible LMV321 derivative these days. Nobody recommends a 741 any more, but a lot are still used in equipment whose design hasn't changed for decades.

--- End quote ---
How is the LMV321 more flexible, than the old LM321? It has some advantages: lower power consumption, bias currents and a rail-to-rail output, but the fact it only works up to 5.5V, rather than 30V, severely limits its applications, making it inflexible compared to the old LM321.

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