Simulating phase noise for PFD-CP

[cupric]

Hi!

I am trying to simulate the phase noise for a phase frequency
detector-charge pump. I have a couple of questions. Hope you can help
me out with this.

(a) In the pnoise tab of the analysis window, if I choose my sweep
type to be relative, what should I choose the relative harmonic to be
(what does this option mean?).
(b) Once I get the noise current plotted. How do I integrate the
waveform over the frequency of interest. When one does a strobed noise
analysis, one gets the option of plotting the integrated noise. But,
this option doesn't appear when I do the normal pnoise analysis (or am
I missing something here). Or, do I need to use the calcultor to do
the integration. Again, how do I use the calculator for this.

Thanking you in anticipation.

cupric

 

[Vikas Vijay]

hi
The relative harmonic should be 1 (which is also the default) because
you need to measure the noise across the central periodic freq of the
output (i. harmonic 1 of the pss analysis). You just need to look at
noise skirts around the central frequency, the harmonics will anyhow
be filtered out by the following LPF stage.
Regarding ur second question i am not very clear.

-vikas

cupricwhistle@yahoo.com (cupric) wrote in message news:<7d250b17.0308031937.310d98a3@posting.google.com>...

Hi!

I am trying to simulate the phase noise for a phase frequency
detector-charge pump. I have a couple of questions. Hope you can help
me out with this.

(a) In the pnoise tab of the analysis window, if I choose my sweep
type to be relative, what should I choose the relative harmonic to be
(what does this option mean?).
(b) Once I get the noise current plotted. How do I integrate the
waveform over the frequency of interest. When one does a strobed noise
analysis, one gets the option of plotting the integrated noise. But,
this option doesn't appear when I do the normal pnoise analysis (or am
I missing something here). Or, do I need to use the calcultor to do
the integration. Again, how do I use the calculator for this.

Thanking you in anticipation.

cupric