raja.cedt wrote on Aug 28th, 2009, 3:08am:hi,
i have a system with some phase margin and i am getting some ringing in the step response, now if i increase system PM, then i know that no of rings will decrease..but how about frequency of ringing?
thanks,
Rajasekhar.
1.) Why do you expect no decrease in ringing ? Normally, ringing becomes smaller with increased PM.
2.) Frequency of ringing is app. identical to the unity gain frequency of the loop gain. Thus, it depends on the method of PM increase which you are going to apply.