Hi Emman and Harry,
Sorry for taking so long getting back to you. I have decided to buy a few of the evaluation boards and test a few things out.
So you guys are right, the load is causing the opamp to go unstable when there is no in series resistor.
So the remaining question regarding this problem is the following. I can now have it stable, but there still seems to be some slew-rate issue at frequencies of around 25 MHz. Here are some measurements
(All on analog's eval-board)
In series resistor= 30 Ohm, no load on output, Comp cap = 1.6 pF;
In series resistor= 30 Ohm, with load on output, Comp cap = 1.6 pF;
In series resistor= 30 Ohm, no load on output, Comp cap = removed
In series resistor= 30 Ohm, with load on output, Comp cap = removed;
In series resistor= none, with load on output, Comp cap = 1.6 pF (probe setting here was on 10x for blue);
In series resistor= none, with load on output, Comp cap = 1.6 pF. The following I can obtain input voltages smaller than 400mV peak-to-peak.;
So these measurements agree well with what I have been seeing for my own board. Could you guys comment on how to choose the series resistor or modify current values of the passive components such that I would no longer have these slew-rate issues.
Thanks again guys, you have helped me so far a lot!
Regards
Ludwig