How can I find open loop gain of this non inverting amplifier. I searched for answer but couldn't find the answer. Using formula Gain=1+R2/R1
I am not able to figure out values ofR2 and R1
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\$\begingroup\$ Google non-inverting buffer \$\endgroup\$– Big6Mar 4, 2017 at 15:19
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2 Answers
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Redraw your amplifier as if it really had resistors per the standard diagram
simulate this circuit – Schematic created using CircuitLab
Now plug the new values into your equation, and what do you get?
answered Mar 4, 2017 at 15:20
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\$\begingroup\$ R1=0, R2=infinity ,Gain=1+ infinity=infinity? \$\endgroup\$– SaqeebMar 4, 2017 at 15:31
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\$\begingroup\$ @FanBoy - Please refer my circuit to whatever you used for your gain equation. Do you see a difference? Like, in component numbering? Plus, your application of my numbers should have given not "1 plus infinity", but rather "1 plus infinity divided by zero", and that should be a clue that something is wrong and you should go back to your original equation. \$\endgroup\$ Mar 4, 2017 at 15:36
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\$\begingroup\$ Okay, but I'm not getting how R= infinity? How did you equate values of R? \$\endgroup\$– SaqeebMar 4, 2017 at 15:41
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1\$\begingroup\$ Since R2 has disappeared from the diagram, no current can flow through it. Please apply Ohm's Law to a resistor, and find the resistance needed to produce no current. Since the output is connected to the + input, there is no voltage difference. Please apply Ohm's Law to a resistor, and find the resistance needed to produce no voltage. \$\endgroup\$ Mar 4, 2017 at 15:43
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One way,directly we can say that output voltage is Vin,as for op-amp voltage at inverting & non-inverting op-amp should be same.
