help!How to use hspice to do noise analysis in PLL?

[selina_wch]

HSPICE manual wrote:
.NOISE v(out) v(in) inter

For example, I'd like to simulate the MOSFET noise contribution to PLL. v(out) is the VCO's out. How to add v(in)? I am able to calculate it using Razavi's fomular
while the result is not accurate and the noise parameters in spicemodel are not uesd. Could anybody help me? I have no spectral tool by hand.

 

[DZC]

Sometimes to use SPECTRE will be more convenient.