opamp circuits

As part of our project work we have to design a circuit using op-amps on PCB giving reasons why we used the resistors of particular value etc.
any suggestions or references?

 

Some details of the circuit function would help.

 

examples include logarithmic circuit, adder & subtractor circuit, Schmitt trigger circuit, integrator circuit all using op-amp.

 

The internet is full of these circuits if you make a search in google. As for the components they depend upon the design.

 

You will find attached the Alice's Restaurant of op amp circuits - the National Semiconductor op amp collection. All ya gotta do is sub in a more modern device than the ones shown. The only thing lacking is the theory.

 

It really has a lot of basic circuits.
Thanks a lot.