Hi carlgrace,
thanks for the reply. Yes its a differential VCO...
Quote:BTW The easiest way to increase the phase margin is to increase the dropout voltage (so you can shrink the pass device).
I think that would be true if my output was the dominant pole, but it seems that the design I inherited has an internal dominant pole. There is no additional capacitance at the output (I believe now that this is the main issue), so now I'm worried that the design will have trouble when the load current has sudden changes. The problem is, if I want to have the output as the dominant pole, it will need a lot of additional capacitance. Maybe I should add a reasonable amount of output capacitance, but keep the internal dominant pole and just shift it lower.
thanks,
Aaron