Hello

I have a need for a simple voltage follower
However, i know it is not as easy in practice as in a text book.
Text book simply shows no resistor and tieing the output back to the inverting terminal
I understand this is not proper.

What is the proper way?

 

hi Mike,
Where did you read that its not proper.?

Look at this AAC link.
https://www.allaboutcircuits.com/video-tutorials/op-amp-applications-voltage-follower/

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Text book simply shows no resistor and tieing the output back to the inverting terminal
I understand this is not proper.

Long ago, back in the days when op amps had large input bias currents (many nanoamps or even several microamps), it was often necessary to balance the impedances seen by the two op amp inputs so that the bias current wouldn't generate an input offset voltage. Hence that resistor (I assume) you were expecting between the op amp's output and its inverting input.

But modern op amps usually have such small input bias currents that extra resistor is no longer necessary. That is why your textbook doesn't show one in the circuit.

 

I understand this is not proper.

What is the proper way?

What makes you think it's not proper? That'a voltage follower configuration that's mentioned in just about every datasheet.

In fact, there's an LM310 voltage follower IC.

 

Just everytime i make a following without a resistor on the feedback and a cap in parallel someone yells at me and says its unstable. I never understood why but just did it

 

Just everytime i make a following without a resistor on the feedback and a cap in parallel someone yells at me and says its unstable.

Are you sure they know what they're talking about?

 

hi,
Do you have an example to post of a voltage follower circuit that you plan to use.?
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