Why isnt Gray&Meyer book and Razavi book doesnt mention anything about OTA?
I Know OTA is an Op-amp without buffer at the output, but for some reason Razavi and Grey&Meyer doesnt mention the term "OTA" in their books. Does anyone know the reason?
gray's book first talk about amplifer with small capacitive load, then, in another charpter, he introduced some output stage structrues for large capacitive load.
The main different between OTA and opamp is in output impedance since OTA is basically a voltage controlled current source. so it has a large output resistance.
Today it seems that many writers do not distinguish between OTA and OPAMP. The reason, i think, is the wide spread of CMOS circuits where a low impedance opamp (e.g. a low impeance output buffer like in 741) is seldem required.