HI ALL,
how can i do the pss and pnoise to PFD and cp.
because when the output of cp can not get into a steady state that i can run pss.

someone told me tie a fixed voltage source to the output of cp, and run pss and pnoise, and at last, measure its noise current.

is it a right way to get the noise?

thanks,

Ken Kundert wrote on Jun 6^th, 2007, 10:46pm:

hi ken,
the paper said:

"In this case, a representative signal would be one that produced periodic switching at the output. This
is necessary to capture the noise present during the switching process."


sorry, i don't  understand very well on above, you means, i can inject two un-matched clock signals purposely, to compensate the mismatch of the charge pump currents. in this case, the output of cp can be produced periodic switching,right?
thanks.

hi Ken,

thanks,
you mean we can tie a constant voltage source, saying 1volts to the output of cp, and inject a clock both to the two inputs of PFD, then do pss and pnoise analysis to probe the current noise of the voltage source. is it right?

thanks again.