I have this filter, i've tried many times to get the transfer function, but i always get it wrong...
Here are the equations i'm using:
(Vin-V1)/R1+(V2-V1)/R2+(V3-V1)/R2=0;
V1=R3Vout(R3+R4);
V2=-VoutR2*sc;
V3=-Vout/R2*sc;
if anyone could give me a hint of what am doin wrong, it would be great.