Who has simulated the Phase Noise of PLL by SpectreRF?

[flyinspace]

pll + spectrerf

Hello,
I have some problems about using PSS & Pnoise analysis in SpectreRF, which can simulate the Phase Noise of PLL. And my design of the PLL is used for clock generator in MCU. So the reference frequency is 1MHz and the VCO is about 30MHz. My problems are:
1, Is the periodic ac source added to the reference signal?
2, If it is, how can I obtain the every block's PN in PLL? For example, I want to get the PN of VCO IN THE LOOP. If I just observe the output of VCO?
3, What's the carrier frequency of the PN simulation result if I observe the different output in PLL, such as VCO, PFD, Filter and Divider? I am sure about the VCO(30MHz), how about the others?

BTW, who can show a PN simulation result about VCO in Artist?

 

[ET]

how to simulate for vco phase noise

Hey, Flyinspace,

I didn't do the simulation of a whole PLL, but I did some phase noise analysis a single LC-Oscillator and a ring-osicllator. Maybe I can help something.

(1) I think an ac source signal is necessary, in terms of your first question.

(2) Let me use ur example, the VCO. After you finished a PSS+Pnoise anaylsis, you will see a pnoise form appearing. Select the "pnoise option" on this form, a phase noise plot will be drawn automatically. The detailed manual can be found via
**broken link removed**

(3) The phase noise of PLL is based on the offset frequency.
Meanwhile, the following URL shows how to simulate PLL using cadence artist. And I also attached a phase noise spectrum of a LC-Oscillator.

**broken link removed**

I don't know why I can't attach my phase noise picture. Sorry about that.

 

[uncle_urfi]

cadence vco noise spectrum

After all is said and done, you should realize that the PSS (pain stakingly slow) simulation (if it ever converges) overestimates the phase noise of a stand alone VCO by about 10 dB. i say this as i have fabricated/tested several ring oscillators.

You have to model a lot of things not modeled by Spectre. For further reference.

Jacobsson, H., et al, “Low-Phase-Noise Low-Power IC VCOs for 5-8-GHz Wireless Applications”, IEEE, Trans. MTT, Vol. 48, No. 12, December 2000, pp. 2533-2539

 

[flyinspace]

how to simulate pll pfd phase noise

Hello,ET
I am very appreciate your help! However, perhaps I have not explained my problems very clearly. Because I have simulated the PN of the alone VCO, such as a simple ring VCO. But I want to know how to get the PN of VCO IN THE PLL LOOP.
What the beat frequency in PSS analysis with the whole PLL when the reference frequency is 1MHz and the VCO is about 30MHz? Is it 1MHz or 30MHz? That is to say, after the PSS analysis, I can get a 1MHz or 30MHz steady state period wave?

 

[flyinspace]

30mhz vco

After all is said and done, you should realize that the PSS (pain stakingly slow) simulation (if it ever converges) overestimates the phase noise of a stand alone VCO by about 10 dB. i say this as i have fabricated/tested several ring oscillators.

You have to model a lot of things not modeled by Spectre. For further reference.

Jacobsson, H., et al, “Low-Phase-Noise Low-Power IC VCOs for 5-8-GHz Wireless Applications”, IEEE, Trans. MTT, Vol. 48, No. 12, December 2000, pp. 2533-2539

Hello, uncle_urfi
Thank you for your information!
For a alone VCO, you mean the PN result from SpectrRF is not accurate?
If the simulation result is -80dbc/Hz @10K, then is the measurement result should be about -70dbc/Hz?
Do you analyze the reasons?

 

[amarnath]

pss analysis pll

i have done a standalone simulation of my vco phase noise.if somebody needs some help they are free to ask.in cadence u need to run pss and pnoise together,pnoise cannot be run standalone.

regards
amarnath

 

[bibhuprasadp]

Re: pss analysis pll

how to calucate the phase noise of the pll using cadence spectre......plssss reply me sir...

regards
bibhu