What's the signal source impedance? That's important to the choice.
Your numbers imply an opamp with a gain-bandwidth product in the tens
of GHz, which no single opamp has. This will need at least two gain
stages.
What's the application?
I am interfacing to a Endevco Model 22 Picomin Piezoelectric accelerometer
(
http://www.bksv.com/pdf/22.pdf) It has a resistance in the G-OHMs and a
capacitance of 250P-F. I don't know enough to figure out the impedance.
My signal is nearly a microvolt when I look at it with a scope but very
noisy. Not just the usual 60Hz, but also a lot of random looking noise.
I am only going to build ten of these, and the boss is paying for the parts,
so cost isn't a big factor.
One dude wrote 'the AD797 has very low voltage noise, but JFET input opamps
tend to have lower current noise'. In my application. am I looking for low
voltage noise or low current noise? What's a good opamp for low current
noise? I want to see if I can do it with opamps only before I try something
with transistors. I find opamps easier to work with. Probly just my lack of
experience though.
Another dude wrote 'If the source is high impedance, consider the first
stage being a FET Opamp'. Sounds good to me. What's a good part number
to try? Is a FET the same as a JFET? I have only used the MOS-FET, and
I had a lot of trouble figuring it out.
Would the AD797 be good for that second stage that I will need?
I would like to read AoE pages 428 to 455. What's an AoE? ;-)
Some of the answers here are a bit over my head, but I am learning a lot.
Thanks for helping a newbie. Maybe someday I will learn enough to be the
one doing the helping!
Sorry for all of the dumb questions...