I need to calculate the gain of this op amp circuit. It look like a differential op amp circuit, but i only have one resistor in the feedback loop, R3.
How to determine the gain of this OP AMP circuit?
The formula is quite simple: -
And, if you have R1 = R2 then the gain magnitude is unity.
Because the +IN signal and -IN signal have to be (within reason) at the same potential, the 1 kohm resistor in your circuit has no effect. Are you aware of this or, do you have a valid reason to incorporate it?