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Measurements >> RF Measurements >> Pnoise analysis, initial point?
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Message started by reactgary on Mar 21^st, 2006, 1:56am

Title: Pnoise analysis, initial point?
Post by reactgary on Mar 21^st, 2006, 1:56am

Hi,
This is my first time to write sth here, I am trying to do noise analysis for my
sc voltage amplifier. To understand the useage of pnoise analysis, I tried some
simple S/H circuit. However, I got some problem with noisetype=timedomain
parameter. In this parameter, we can specifc the point which noise is being
measured. e.g. if we have 10us clock cycle, we can measure any point
between 0 to 10us. But what is the meaning of the specified point (e.g 4us)?
is that 0us is the rising edge of my clock signal? How about a multiple clock
circuit with different delay but same freq?
Maybe a silly question, thank you !
Gary

Title: Re: Pnoise analysis, initial point?
Post by Andrew Beckett on Mar 29^th, 2006, 1:03pm

The time is relative to the start of the single period of the PSS fundamental. If you plot the time domain waveforms from the PSS, you'll see what is time zero - it's also clear from the output log where the PSS shooting interval starts.

The shooting interval in PSS starts after t_onset+t_stab+1 cycle - t_onset is the onset of periodicity (after any non-periodic sources, or delays on sources have completed), and t_stab is the additional stabilization time (if any) that the user supplied.

Regards,

Andrew.