[sdiy] Using Opamps as INV or NON-INV amplifiers

[Steve Lenham]

> Apart from the gain being minimum of 1 for a non-inverting amp, are there
> any other advantages or gotchas about using one form or another? There's
> lots of stuff about op-amps out there, but I'm still a bit unsure about 
> the
> practical differences in use. It would seem that a single NON INV amp is
> easier to implement, and yet often the INV configuration is used, with a
> second re-inverting stage ...
>
> Any thoughts welcome.

Analogue guru Jim Williams* points out that  the inverting configuration 
avoids any problems caused by non-ideal common-mode performance of the 
opamp, since there is (pretty much) no common mode signal on the input pins. 
The non-inverting configuration remains susceptible to such effects.

Steve L.

*in his highly recommended book "Analog Circuit Design: Art, Science and 
Personalities"