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Measurements >> Phase Noise and Jitter Measurements >> long term jitter measurment.
https://designers-guide.org/forum/YaBB.pl?num=1106551797

Message started by bhaijiamit on Jan 23^rd, 2005, 11:29pm

Title: long term jitter measurment.
Post by bhaijiamit on Jan 23^rd, 2005, 11:29pm

I was trying a verilog-A model to calculate jitter and phase noise. I have following issue regarding the measurement of long term jitter. How exactly can i calculate the same. In my present verilog-A model for the VCO I am dumping the $realtime. To calculate the N-period long term jitter I am using following matlab commands

Code:

for I=1:1:100000,
x(I)=time_long(I+nperiod)-time_long(I);
end
std(x)

(here nperiod is period for which I need to calculate the jitter and time_long is simulation dump file.)

Now my question is: since the division ratio in my design is 10, do I need to divide this standard deviation by sqrt(ratio) as I would do if I were calculating the period jitter (I feel that I do not need to)? Can anyone suggest a better method to measure the long term jitter?
Regards
Amit