What is the PLL's noise?

[wjlzhx]

Hi friends!!

what is the pll's noise ??
only the phase noise??
my pll is type2 ord2

could you help ?
and tell me what is the phase noise??how to calculate it??
how to simulate it??

thank you a lot!!

 

[lijianheng]

Re: PLL noise

PLL noise include reference osc noise, charge pump noise, VCO noise and divider noise.

Their noise transfer function in close loop are different, you can read the book about analog circuit including PLL.

Phase noise is the output noise of VCO, you can read this book: Thomas Lee, The Design of CMOS Radio-Frequency Integrated Circuit.

simulate phase noise you can use spectre, read the manual of spectreRF.

 

[khouly]

Re: PLL noise

PLL noise , is mainly the phase noise
the closed loop PLL has many transfer functions of noise , everyone depend on the source of the noise
1) reffernce PLL act as a low pass filter
2) filter PLL act as a low pass filter
3) VCO PLL act as high pass filter

to simulate the PLL phase noise , u can use any system level simulator , if ur PLL in circuit level u will used SpecrtreRF PSS analysis to get the phase noise

khouly

 

[shaikhsarfraz]

Re: PLL noise

Hi,

Phase noise is the PLL noise.

Perform PNOISE analysis along with PSS analysis in Spectre and you can simulate the phase noise.

thanks
sarfraz

 

[Joestar]

Re: PLL noise

the pll noise is phase noise
named phase noise because the noise effect the phase of the output signal
the sub blocks of the pll has its own noise

Hi friends!!

what is the pll's noise ??
only the phase noise??
my pll is type2 ord2

could you help ?
and tell me what is the phase noise??how to calculate it??
how to simulate it??

thank you a lot!!

 

[selina_wch]

PLL noise

Find the noise source of different part of PLL, then add noise on it . After transit simulation, you will find the clock jitter.

 

[wjlzhx]

PLL noise

I have not use the PSS.
so how to use it????
could somebody can tell me??

 

[ranjan123]

Re: PLL noise

Go through the sections on phase noise in couple books on PLL - Roland Best has a good book on PLL, there are several others that you can find on Amazon. Also, I would recommend reading an App Note by Motorola on PLL design.

For pss, Cadence has good design notes and explains how pss works and how to use in the Analog Artist environment.