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?
Answer
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 This outdated part therefor gets introduced into new designs from copying legacy modular designs, and familiarity from instruction.
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