I am to design an OTA for a pipelined ADC with 2.5 bits/stage.
These are the apparent specs of the OTA

Voltage swing = 1 Vp-p differential
Gain = 60db
GBW = 100MHz
PM=70 degrees
GM=10db
Current consumption = 300uA max

hi, you have to specify the load cap also, because you have around 300ua with this are you able to get required Ugb?  And getting 70db gain also difficult in one stage but with your current spec you should bound with single stage so better use cascode with gain boosting.I understood all specification derivation but how did you come up with required gain margin?

thanks,
rajasekhar.

I think your supply is too low to do a cascoded one stage scheme.  go with a two stage miller OTA.  You will need to know what your load cap is, in order to compensate the amp.