Hi, Yawei,
Looks to me that you are using BSIM3 models, as the
noise flags in BSIM4 are TNOIMOD and FNOIMODE.
There are 2 types of mosfet noise models in BSIM3:
1.Hspice mosfet noise model ~ NLEV, AF, KF and GDSNOI
2.Berkeley mosfet noise model ~ NOIMOD, NOIA, NOIB, NOIC, EM, AF, EF, KF and GDSNOI.
For NOIMOD 1, spice2 noise model is used for flicker noise,
which is a function of Ids, Leff and f. For NLEV3, the
flicker noise is a function of gm, Leff, Weff, and f. So, even
for the same process from the same fountry, and the same
design, the flicker noise should not be the same.
>Does the flicker noise of MOS transistor vary so much >(about 2 order of magnitude) from one generation to >next generation?
It should not be that different. Please check the KF value
in your spice models.
>I will check them again and try to figure out the equation >of both noise model.
You can refer to the following for details:
For Hspice noise model:
Hspice MOSFET models manual -> Chapter 2 Technical
Summary of MOSFET Models -> Noise models
For Berkely noise mode:
BSIM3V3 Manual -> Chapter 8 Noise Models
The BSIM3V3 manual URL:
http://www-device.eecs.berkeley.edu/~bsim3/arch_ftp.htmlLet me know if I can provide you with further info.
Thanks.
--Charlie