I am sure you are aware of how impossible your targets are - but, maybe can get close.
1. Your noise targets imply a decompensated VFA
2. Your slew rate needs imply a current feedback output stage
When I need this I go to a composite structure where I essentially replace the VFA output stage with a CFA stage.
1. To shif the slew rate burden to the CFA, I operate that new output stage (inside the loop) at some gain, -4V/V here.
2. To get the highest slew rate and shortest prop delay inside the loop, I operate the CFA inverting.
3. Since I now have an inverting output stage inside the loop, I flip the feedback connection around to the V+ node for the VFA
4. I have essentially gained up the intrinsic GBP for the VFA by a factor 4 here - and, its min stable gain number.
The final trick is an inverting compenstation method I developed many years ago and recently republished on EDN. inserted here.
https://www.edn.com/unique-compensation-technique-tames-high-bandwidth-voltage-feedback-op-amps-2/
This will give you the noise target at low F, but for stability these caps are shaping the noise gain up (I targeted 30V/V at high F) to get good phase margin at LG xover. Closer but probably not what you want.
The frequency response looks pretty good actually (and you cannot do this non-inverting - I was guessing a 50ohm source to a 50ohm inverting input Rg with 100ohm feedback).
The spot noise does what I would expect, but 3.3nV at low frequencies, 19nV at 60MHz
The CFA is driving a pretty heavy load here, 100ohm feedback with 200ohm load. With +/-2V output, might be ok with the OPA695 - I chose it for the highest slew rate, not the highest output current - the THS3491 is the most lunatic fringe part these days on both specs, but cannot operate down to +/-5V supplies.
And this file,
Oh well yes Gruffalo, if you need to drive parallel V+ inputs need to go a different direction,
Long time ago, we were pursuing how to push CFA down in Noise and HD. OA-22 is an app note I wrote at Comlinear exploring one way to do that, here is that circuit, parallel feedback networks at low F, transitioned out by a coupling inductor,
Page 9 in this,
https://www.ti.com/lit/an/snoa394b/snoa394b.pdf
The output noise has a large inverting current noise term that this reduces, here is that spot noise sim, about 7nV at 60Mhz,
The OPA695 has a triple version, OPA3695, and you can of course adapt this to the LMH6702.
And then of course if cost and complexity is no problem, paralleling stages will also reduce noise,
Here are 4 of those stages combined at the output through 50ohm R (you never said your load, I used 200ohm here), still a pretty good response shape,
And some improvement in noise at the load, 4.6nV midband, 4.9nV at 60Mhz.
Gain of 2 parallel feedback parallel stages.TSC
And then if I drop the LMH6702 into this same design, there you go, 3nV noise at the load, So maybe not so impossible after all,
And the frequency response looks really good,
A brief explanation how paralleling of OPAmps can decrease the total noise can be seen in the below figure:
Kai
