Hi there,

When I look at the tutorial (shown following, "Characterizing Differential Amplifier.. " by Jonathan David)

http://engr.smu.edu/orgs/ssc/slides/20001215b.pdf

I am not clear for how to measure CMFB stability on its slide 31 and 32. My questions are:
1. For which loop gain should we simulate in order to get CMFB stability?

2. Someone mentioned to me there is CMFB loop gain. Is that same with common-mode loop gain? I am total confused, what is different among loop gain and these loop gains? Can someone guide me here?

3. Even if we get CMFB stability results, say like the slide 32, how can I tell that it is stable or not?

4. another question is related to Step response. On the slide 20, there is plot for step response. I know I can calcuate the Slew rate by hand. So, for step response plot, the measured slew rates shown on that slide are just the slops of those ramps for output responses? Am I correct?

Any instruction will be really appreciated.

ethan