- 598
- 43
- Homework Statement
- What is input and output impedance of opamp in circuit
- Homework Equations
- Input impedance is infinity, output impedance is 0
I know for ideal opamp the input Z is infinite, and output Z is 0, but not sure about this opamp.
The picture is very hard to see. Is is connected as a simple follower?Problem Statement: What is input and output impedance of opamp in circuit
Relevant Equations: Input impedance is infinity, output impedance is 0
View attachment 244354
I know for ideal opamp the input Z is infinite, and output Z is 0, but not sure about this opamp.
The resistance between input signal source and ground would be same as resistance between signal source and input of opamp, which is zero here. Now since the non-inverting terminal is grounded, then the inverting terminal is also grounded, so the entire input signal shorts to the ground?? But the input impedance of opamp is very high.When the voltage difference between both inputs is nearly zero (for the model of an IDEAL opamp it is identical to zero), what then is the resistance between the input signal source and ground?
Yes, the input impedance of the op-amp itself is high... and it is connected in parallel with the output impedance which is low (almost Zero).But the input impedance of opamp is very high.
Zero ohm resistor. So the input impedance of circuit is 0 ohm and the output impedance is also 0 ohm.Yes, the input impedance of the op-amp itself is high... and it is connected in parallel with the output impedance which is low (almost Zero).
So what is the the parallel impedance of a high value resistor paralleled by a Zero Ohm resistor?
But in your circuit there is no resistor R1. If there would be one, why didn`t you show it?I went through this link that says the input impedance is R1.
https://www.electronics-notes.com/articles/analogue_circuits/operational-amplifier-op-amp/input-impedance.php
Ref: Opamp Input Impedance
There is an inverting opamp circuit with imput Z = R1.
R1 is not in the question. I couldn't find the circuit in question, anywhere in the book about opamp. So I searched for input resistance of opamp and the link came up.But in your circuit there is no resistor R1. If there would be one, why didn`t you show it?
In this case, the answer would be different, of course.
Rule: A good and correct answer requires a good, clear and correct question.
It's all right. No problem...Sorry - I have responded to your post #8 in which you have mentioned R1.
I will not repeat such an error....sorry.
I withdraw....