Comparators basics and analysis

[steamedhams]

I am investigating comparators using cadence but frustrated because I cannot discuss with other students because we are all studying from home.. but they aren't really into discussing stuff anyways so here I am. (My course is more about using cadence than comparator design.)

My tutor asked me the following questions. Any feedback would be appreciated.

1. Explain the difference between PSS and TRAN simulations. Why discrete-time circuits should be characterized using a PSS.
PSS will display the output after it becomes periodic. TRAN will display the output over a period of time.
Discrete-time circuits will produce a sequence of quantities after the initial stage which means PSS should be used.

2.What is the periodic steady state transfer function? Which simulation in Cadence could provide you a periodic steady state transfer function?
I believe it was Pnoise but after a quick good, it appears I can also use the following tool:
Periodic transfer function analysis (PXF).

3.What is a PNOISE simulation? Which sources of noise could be taken into account with a PNOISE analysis?
The Pnoise computes the effect of the periodically time-varying bias point on the device that generates noise.
Which noise sources... thermal, flicker. Any noise that is periodic i am guessing?