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Measurements >> Phase Noise and Jitter Measurements >> VCO and frequency divider
https://designers-guide.org/forum/YaBB.pl?num=1170666464

Message started by paulcktang on Feb 5^th, 2007, 1:07am

Title: VCO and frequency divider
Post by paulcktang on Feb 5^th, 2007, 1:07am

I am new to phase noise simulation. I now simulate a combined vco and frequency divider. VCO frequency is 200 MHz and divider is in 8 divide ratio.

I followed the ways described here to find the phase noise of VCO as I can choose the oscillator node as VCO output.

However, I can't find the phase noise of frequency divider because the phase noise at the output of divider is the total phase noise of VCO and divider. Am I right?

Besides, if I know both the phase noise of VCO and frequency divider, how can I calculate the contribution of these phase noise to PLL system?

THANKS A LOT