Hi,
First I want to know hoe does spectre compute flicker and thermal noise
1) using a current modelbetween drain and source
2) using a voltage model at the gate
I am using BSIM 4.5 models where doc says both are modled as current source.
Second,
I have simulated noise transfer function of thermal & flicker noise
of M1 from RF to IF using pss+pnoise and noise separation.
(sideband=+1). Why are they different? I believe both thermal and
flicker are modeled as current source and hence transfer function should
be same. The transistor model is BSIM 4.5 and noise model is holistic.
Is it because contribution from noise source modulation is different for
them?
I tried modeling the noise using a current source (red)
and use PXF analysis. But the gain is around 150 in contrast with 1.2K
from pnoise simulation. Why is pxf resulting in such low value? Is this
method of modeling noise not correct?