question about bandgap with a CTAT current generator ?

[cmos_ajay]

Attached is a circuit of a bandgap core with CTAT current generator.
My question is :
* How many feedback paths / loops are in the circuit looking at the left side of the drawn red line ?

* What are the approximate values of the dominant and non dominant poles as well as the zero in the circuit ?

* To do a stability analysis in Cadence, where do I cut the feedback loop ?

 

[erikl]

I can see 2 loops:
an inner one: Qn3 - Mpp2 - Mpp1 - Qn1,2 - Qn3
and an outer one:
Qn3 - Qn5 - Mpb1 - Mpb2 - Qn3

For stb analysis, cut at the base of Qn3, thus both loops are implied.

For poles and zeroes use the PZ analysis.