I'm looking forward for a opamp design with 70 to 80dB gain. My opamp need to be differential to single ended output to be used as an error amplifier. Please suggest me any folded cascode opamp (NMOS input stage) with single ended output. Any journals or technical paper of schematic will be helpful.
If u have any text books like Razavi, David Jones its not complex to design it and u can change dimensions r u can add an output stage based on ur application where ur using it.
To obtain gains as high as 80dB, a two stage amplifier seems more convenient. You may use a folded cascode as the first stage (easily 40 to 50dB), and add 30dB more with a common source second stage (with Miller compensation).