What are important parameters for an op. amp. used to AC couple and bias a sine signal to prevent noise/distorsion

analogoperational-amplifier

As I am not very skilled with analog design I would like to get some pointers to what to look for/avoid common pitfalls.

I have a signal generator that outputs a sine wave. I want to center this sine wave at a specific voltage (V+/2). So the circuit I am designing is shown in the picture below.

What are the most important parameters to approach the ideal op. amp. in this case?

Other information that might be useful:

  • It is to be used on a battery-driven devices so low power consumption is positive.

  • Rail-to-Rail Input / Output.

  • 3.3V op. amp. preferred.

Circuit:

enter image description here

Best Answer

If you are looking for a specific OpAmp chip I'm sorry, I'm not familiar with any 3.5 V ones.

About other things, if it will be a battery driven device make sure the input impedance is high ( to consume less current ). Usually (extra) high input impedance OpAmps are doing worse with noise characteristics, but if that's not of terrible importance the trade off is good ( of course, you can also find OpAmps with many good characteristics, but it will be costly ). Also about noise, I assume this part of scheme will be a power stage, so I assume you will do some filtering at the output anyway. Also don't forget to check about the input bias currents, you want to keep them minimal - usually this comes at a cost of input current offset, but again, if precision is not at steak it is ok.

Oh and by the way, putting op-amp ( or the like ) tag would really help you get more potential good answers to your question ;)