for a two stage opa as Allen described,with a compensation cap,with the cadence pz analysis,found that there are 5 poles,5 zeros ,is that right? somebody said that should cancel some pole-zero pair,how should I do that?
Is the pz analysis correct? How others usually do?
that I have another question,I found that nmos's Kp is 6 times of pmos' in tsmc 0.18um technology when I design a rail to rail constant-gm opa ,but in books ,it is usually 2-3 times.Is it because of in sub-micron process ,some complicated effect?
Thanks!