I have a circuit with the transfer function: Vo/Vi=-R2/R1

How do I get the 3dB frequency from this?
Is it where 20log(Vo/Vi)=1/sqrt(2) ?

 

The transfer coefficient for the relationship you give is constant for all frequencies - there is is effectively no cut-off frequency.

 

That is what I thought but I looked at the question again and it gave me GB=2MHz
so I did 2pi(MHz)=(R2/R1)w

 

Can you provide a schematic so that we may see what it looks like?

hgmjr

 

forgot to say its an op amp circuit

 

The limiting factor is the slew rate of the op amp.

 

Slew rate can limit the response for large signals. But, for small signals it is the gain bandwidth which limits the response.

The key thing which is apparent here is that insufficient information has been given so far. We need to know more about the properties of the opamp and whether the analysis is for large signals or a small signal approximation.

I would guess that the problem has given a gain bandwidth, or an open loop gain with a pole location, and is asking about small signal gain.

 

GB was givin and it is 2MHz
I was in class when i was posting earlier and some things were cleared up about this question so i might know how to solve it