# Help with transfer function

#### gil15

Joined Jan 12, 2021
1
I have the following circuit and i want to calculate the transfer function.
i know that v+ is the voltage divider between R2 and the impedance of C2 but i dont know how to
express v- so i can use the equation provided for Vout.

#### ericgibbs

Joined Jan 29, 2010
16,037
hi gil15,
Welcome to AAC.

As this is Homework please post your best attempt at answering the question, we can then help you.

E

#### LvW

Joined Jun 13, 2013
1,486
I have the following circuit and i want to calculate the transfer function.
i know that v+ is the voltage divider between R2 and the impedance of C2 but i dont know how to
express v- so i can use the equation provided for Vout.
Have you heard about the superposition theorem?

#### neonstrobe

Joined May 15, 2009
181
Are you familiar with complex numbers?
They might seem daunting at first but make problems like this easier.

#### RBR1317

Joined Nov 13, 2010
701
A transfer function is usually given as magnitude & phase as a function of frequency. The equation given for the op-amp shows simple gain (A) but no time delay (phase). So that makes it easy to find the transfer function.

#### MrAl

Joined Jun 17, 2014
9,357
It looks like the way they want you to do this problem is to calculate the signal at the non inverting terminal (vp=V+) and then the signal at the inverting terminal (vn=V-) and then calculate:
Vout=A*(vp-vn)

This leads to an expression with Vout on both sides so then you solve for Vout explicitly.
That is a very typical way to solve these problems anyway.

To get the theoretical limit of what the circuit is capable of you take the limit as A goes to infinity, but for this problem it looks like they want you to use a finite value for the gain A which is stated as:
A=10000.