Looking for a PLL AC model

[holddreams]

About PLL AC model...

Can anyone give a PLL AC model?
I have searched,but found nothing.
Thanks.

 

[yaxazaa]

Re: About PLL AC model...

What do you mean AC model? Do you mean you want use this to extract stablity parameters? If it's, then just use the open loop transfer function.

 

[Miguel Gaspar]

About PLL AC model...

H(s) = Ko Kd F(s)/S/(1+Ko Kd F(s)/s)

where F(S) is the transfer function of the 1,2, 3, 4 order filter.

 

[holddreams]

Re: About PLL AC model...

Thank you.
Yes ,i want to use the ac model to extract stablity parameters.

How can i use the tranfer function in Hspice to do stablity analysis?

 

[bob_lv]

About PLL AC model...

you can simulate the transfer function in matlab or mathcad,etc...

 

[Miguel Gaspar]

About PLL AC model...

You can consult the aplication note for the 74HC4046 PLL of philips:
www.philips.com, there you can consult the stability parameters that your are looking up for.