RobG wrote on Feb 25th, 2011, 7:42am:Ahuja compensation is the cascode compensation I was referring to, so yes I tried it. The problem I run into is that the gm of the output device is very large compared to the cascode device so there is frequency peaking. In addition, noise from the cascode device is pretty much directly coupled to the output device via the compensation capacitor.
rg
Note that the original Ahuja compensation scheme has no cascode, but a separate CG branch which is used for generating the virtual ground return. However several derivatives of the scheme using cascodes appear in the literature under the title of Ahuja compensation.
In my experience, the orginal scheme allows far easier compensation with very few problems related to peaking etc. than any of the cascoded versions as the cascode device is now seeing the signal and trying to realize a virtual ground at the same time, which makes life hard for it.
Please take a look at the original from the JSSC paper. It won't solve all your problems but maybe the compensation.
Vivek