Questions about CMFB loop

[safwatonline]

CMFB

hello,
i was checking the stability of a CMFB loop , so i tried using the stability analysis in Cadence i got the PM and GM, but i want to know the zero's and pole's for compansation,
my question is can i cut the loop in any node "and add AC source wth approximate DC of this point taken 4m transient analysis", or there is some kind of better nodes and is the approximate DC value is suffiecnt "note that the DC is varing
and i already suffer from oscillations"or should i expect wrong curves, also should i neglect the loading effect after cutting the loop?
thnx,
a.safwat

 

[zkkbmy]

CMFB

1.Cut off a loop shall be keep the load effect as before cut off this loop, that mean the DC value shall be keep as before.
2. The better cut off node in the loop is the side of the node is the lowest output resistor and the other side of the node is the highest input resistor.
3. I think the simulation method of a opam can be a reference for you.

 

[safwatonline]

CMFB

hekoo zkkbmy,
what is the simulation methode of opam , is it a tuturial ,if so plz upload it.
thnx,
a.safwat