The Designer's Guide Community Forum

The Designer's Guide Community Forum
https://designers-guide.org/forum/YaBB.pl
Modeling >> Behavioral Models >> Mathcad model fractional pll
https://designers-guide.org/forum/YaBB.pl?num=1170245229

Message started by dhirajv12 on Jan 31^st, 2007, 4:07am

Title: Mathcad model fractional pll
Post by dhirajv12 on Jan 31^st, 2007, 4:07am

Hello,
How can I model the second order sigma delta for the fractional pll.
How I can I show the bit sequence which is fed to the divider has LSB's changing from 1 to 0 which provides the average value of the division factor required.And how to print the average value.
Is there any specific equation set for this.
Can you give the source where I can get a matchcad model for this purpose.I have a model of sigma delta converter which plots the quantization noise plot with respect to frequency.How is this applicable to fractional pll

regards
dhiraj

Title: Re: Mathcad model fractional pll
Post by imtired on Jun 5^th, 2007, 2:13pm

Hi dhiraj,

I'm having a hard time understanding your question.
Are you trying to simulate the frac-N PLL in the time domain?
Or are you trying to model the phase noise / stability of the frac-N PLL?

Regards,
Robert