Hello, I would like to know how an operational amplifier works and what it is used for, some applications, thank you very much

 

There is this tool called Google that you might have heard of....

Bob

 

The operational amplifier is perhaps the most important invention in all of electronics apart from the transistor itself.

What is an operational amplifier?

An opamp is a wide bandwidth amplifier with high gain. An ideal opamp is commonly treated as a functional black box in circuit design without requiring any knowledge of the internals of its construction.

An ideal opamp has the following properties:

1. Infinite input impedance
2. Zero output impedance
3. Infinite voltage gain
4. Infinite bandwidth

With such perfect properties, the application of opamp is without limit.

Reference: https://en.wikipedia.org/wiki/Operational_amplifier

 

Don't forget that modern operational amplifiers have a differential input with ideally zero DC offset (but the first tube operational amps only had a negative input referenced to ground).

 

The operational amplifier is perhaps the most important invention in all of electronics apart from the transistor itself.

....and the most important property of the opamp is the following:
Due to is huge open-loop gain it must be always used with negative feedback - and it is the feedback factor alone (composed of resistors and/or capacitors) that determines the closed-loop gain properties.

 

The operational amplifier is perhaps the most important invention in all of electronics apart from the transistor itself.

I like to say it's the Swiss Army Knife of analog components.

 

....and the most important property of the opamp is the following:
Due to is huge open-loop gain it must be always used with negative feedback - and it is the feedback factor alone (composed of resistors and/or capacitors) that determines the closed-loop gain properties.

To be pedantic, this is not a property of the opamp.
The significant property is the very high open-loop gain (or infinite gain in an ideal op-amp).
This makes the opamp ideal for formulating an analog comparator.

The use of negative feedback is a requirement of the circuit topology if one wants to constrain the gain of the circuit.

 

Hello, I would like to know how an operational amplifier works and what it is used for, some applications, thank you very much

What is life?

How to describe the Universe?

Where the wind goes when it is not blowing?

All nice questions.

Felipito: put some effort from your side.

 

To be pedantic, this is not a property of the opamp.
The significant property is the very high open-loop gain (or infinite gain in an ideal op-amp).
This makes the opamp ideal for formulating an analog comparator.
The use of negative feedback is a requirement of the circuit topology if one wants to constrain the gain of the circuit.

OK - agreed. But notice that the questioner also has asked "what it is used for...?".
On the other hand - why is the opamp equipped with such a large open-loop gain?
Answer: Because we want that the transfer properties are determined by the feedback network only.

 

What is life?

How to describe the Universe?

Where the wind goes when it is not blowing?

All nice questions.

Felipito: put some effort from your side.

Felipito is from your part of the Universe. Maybe you can help him out in PM.

 

Hi Felipe, what about trying to get "Op amps for everyone" - 3rd edition - 2009 - TI by Ron Mancini / Bruce Carter?

The most reasonable introduction I've ever read. Pity I got it 20 years late.

By the way, Ron Mancini is member of this forum.

 

"Op amps for everyone" - link
http://index-of.es/z0ro-Repository-...ne, third edition 2009 (Texas Instrument).pdf