Poles and Zeros of Voltage Regulator

[1mace1]

How can the poles and zeros of the attached circuit be estimated?

If the cap C1 is working as miller cap you can simplay say that the inupt of Gm2 sees sC1Gm2 and at the output of second stage simply sees C1 to gnd.

But in this case it is not working as miller cap how can I estimate the capacitor respectively the poles then?

 

[1mace1]

Can the capacitance C1 be modeled as negative miller cpacitance with -gm2*Ro2*C1 on the input?
Tha would mean that this pole is a RHP pole and introduces +90 degree phaseshift.