@checkmate: Haha. I will try it out someday. I have till the end of this month to hand my assignment in, however, so no time right now.
@Jimito13:Vdd=3.3V, Vss=0V. Thanks a lot! I tried your approach but the problem was a very simple, stupid one.The Vin was biased out of ICMR. Am getting a 45 db gain now with decent UGB
However, the specs given to me are insane. 120 db DC gain with 180 db CMRR and only 0.5mA total current budget! For the present I am trying to use gain-boosting. So, yeah, again a couple of questions
1) I saw lots of different looking gain boosting circuits online. Any idea which gain-boosting circuit could be best for fully differential folded cascode?? A simple diagram would be more than enough.
2)How high can gain-boosting boost my circuit actually?
3)To get my insanely high CMRR, increasing the Rss is an option, using cascaded MOSes. But this will eat into my voltage headroom and kill my voltage swing. Also, my MOSes are all very precariously biased. Any other way except the "Rss way" to increase CMRR?