Re: PMOS diff pair as 1st stage and nmos common source 2nd s
ok, i can till u from my experience that using the PMOS transistor has many disadvantages because is reducing the the gain and the phase margin(phase margin is related to selw rate) of the OP AMP, advantage of using PMOS is low fliker ngardsoise whish can be solved by using many techniques, my advice to u if u r looking to design high performance OP AMP use NMOS, pls if i am not correct, correct me
regards