# Given a transfer function i want an op amp represantation

I have a project for my university on the transfer function (where a,b,c are constants):

$$G(s)=\frac{(s+a)}{(s^2+bs+c)}$$

and I'm asking how to represent this whole thing with an OPAmp circuit.

(The difficult part that got me the most time thinking, is the numerator) I would like some help in order to implement it myself and not an immediate solution.

• Your transfer function has one zero and two poles. There's many ways to implement this using op-amps. One thing to consider is that the best implementation might depend on whether the poles are real or complex. – The Photon Dec 22 '15 at 5:34
• Look at 'controller canonic' form of a TF. This method has no restriction on real/complex poles. – Chu Dec 22 '15 at 9:47
• Are you expected to vary a, b and c independently and demonstrate what happens or are you looking for any op-amp solution that is if the general form of your equation. Think about this because one option is really tricky. – Andy aka Dec 22 '15 at 9:53
• i have specific values for a,b,c ... poles are complex. I just wanted some general help so i didn't fit in the values. – lefkadios Dec 22 '15 at 20:34

since this is 2nd-order, consider the Sallen-Key circuit and add to it another op-amp circuit that sums (with weighting factors) the voltages at $V_\text{OUT}$ and $V_\text{x}$. (reference to Figure 1.)