Opamp feedack: series RC

[qolpa]

Hi all,

I have been wondering for a long time what is the purpose of series R2 C2?(see attached) The other part of circuit is not important.

I think it is some kind of filter but how can we calculate the corner freq, is it like basic low-pass or high pass RC? (1/2*pi*R*C ??)

Any help would be appreciated..

[gopi_sonsivri]

it is circuit for integrator

i think the order of filter is fixed by the R2,C2 (second order)

Just read some book on Linear Integrated Circuits

[hate]

The impedance of the feedback circuit consisting of C1,C2,R2 is Z=(R2*C2*s+1)/[R2*C1*C2*s*s+(C1+C2)*s] which looks like a bandpass filter. And the input output relationship is Vo=[5*(R1+Z)/R1]-Vi*Z/R1. If the non-inverting input should be grounded instead of being connected to 5v, the transfer function would consist of only the 2nd term and this would look like a bandpass filter to me. With the non-inverting input connected to 5v it looks like a mixer with filtering capabilities. Try to Bode plot the transfer function!

Regards...