wholx
Member level 4
the opamp is used as a buffer in a mixed-signal circuit. the input stage is composed of two differential pairs (folded-cascode) to achieve high input CM range. my quesiton is about the output stage, i guess PP15 and NP3 are used to avoid the class B output PP14 and NP4 blocked at the same time, but i'm not sure. anyone can explain how exactly do pp15 and np3 work in the circuit?