What's the feedback for an op amp?

[Alaguraja]

What's the feedback for an op amp? And tell me the formula.

 

[davenn]

What's the feedback for an op amp? And tell me the formula.

you use resistors to adjust the feedback level to produce the required gain
watch this video and then come back with any questions on anything your didn't understand

https://www.eevblog.com/2014/04/06/eevblog-600-opamps-explained/Dave

 

[Alaguraja]

Thank you for this video. And I need formula to find the frequency.

 

[davenn]

And I need formula to find the frequency.

what frequency ?

 

[Alaguraja]

The output wave's frequency.

 

[davenn]

The output wave's frequency.

it's going to be the same as the input, why do you think it would change ?

consider ... if I am using an op-amp as a microphone preamplifier, the last thing I am likely to want is the frequency to be changingDave

 

[LvW]

What's the feedback for an op amp? And tell me the formula.

When applying feedback to an amplifier, we send a certain part of the amplified output signal back to the input - and superimpose both parts (input and feedback signal).
In most cases, we make use of NEGATIVE feedback where the feedback signal is substracted from the input. This method has many advantages: Bandwidth increase, linearity improvement, gain reduction with reduced sensitivity of the gain value against uncertainties and tolerances of the active element.

However - as everything in electronics is a trade-off between conflicting requirements - negative feedback has one disadvantage: The stability of the circuit against unwanted oscillations (self-excitement) is reduced. With other words: The stability margin is reduced.