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What is this op-amp configuration?

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ECE101

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Just wondering if someone could describe the function of the circuit below?

se3txz.jpg


Is it some form of Inductance gyrator?

The input is the non inverting input.
It has negative feedback and also low pass filtered positive feedback?
 

The function of the circuit depends on the internal resistance Rin of the signal source that is applied at the non-inv. input.
For a pure voltage source (Rin=0) the positive feedback path is useless.
 
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    ECE101

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Please show us your exact schematic. I am kinda not getting.
It may be gyrator or the form of first order sallen-key topology.
 
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..................
.......... or the form of first order sallen-key topology.
What is this? Sallen-Key stages are always of 2nd order
Sorry I was assuming the form of butter worth -topology.
 
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Please show us your exact schematic. I am kinda not getting.
It may be gyrator or the form of first order sallen-key topology.

Apologies! I had my inputs reversed.

Here is the correct schematic:

2s6m49i.png


It seems to be a low pass filter but still what would be the purpose of the 2 resistors connected between the output, ground and non inverting input?
 

Sorry I was assuming the form of butter worth -topology.

I know - probably it will be not to important for ECE101, nevertheless it should be clear:
"Butterworth" is not a term describing any filter topology but rather a certain kind of transfer function response (of at least second order).
A lowpass of first order has one possible response only - there are no alternatives (except the gain).
But I agree, ECE101 should show the complete schematic including signal source circuitry and grounding (no open nodes).
 
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    ECE101

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Thank you for your replies LvW,

This is the only schematic I was given.

Exactly as above, It was actually for a pop-quiz where it was asked to describe its function.
 

<It seems to be a low pass filter but still what would be the purpose of the 2 resistors connected between the output, ground and non inverting input?>
One reason, hysteresis..
 
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    ECE101

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Thank you for your replies LvW,
This is the only schematic I was given.
Exactly as above, It was actually for a pop-quiz where it was asked to describe its function.

Hi ECE, to answer your question it is necessary to know about the parts values - in particular if positive dc feedback dominates or not.
(This point was also addressed by varunkant: hysteresis yes/no ?).
 
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    ECE101

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well its simply an "INTEGRATOR" , which can be commonly referred to as LPF !
 
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