R1 = R2 = 1/2*pi*fc*C //choose C = 0.1uF
R3 = R1/2
K = 1 - (1/4Q) // Q is the quality factor.
this is the Twin Tee notch filter. ( Twin is because there are two star networks )
can anyone please give the transfer function of this circuit?
Thanks

 

http://lmgtfy.com/?q=Twin-Tee+Transfer+Function

3rd Hit is a nifty design tool

 

I analyzed the circuit and without opamp im getting the transfer function, but with a positive feedback op-amp, want to know how will the transfer function change?

 

I analyzed the circuit and without opamp im getting the transfer function, but with a positive feedback op-amp, want to know how will the transfer function change?

If it is a unity-gain follower with a high frequency rolloff at 10 times the notch frequency there should be a minimal effect.