avlsi wrote on Sep 20th, 2006, 5:02am:Hi guys,
I would like to enlighten you about the flicker noise co-efficient.
There are two formulas for flicker noise
1. simple using Kf and Af
2. using q,noia,noib,noic,ef .. etc
Generally for noimd= 1, simple formula is used. This is not accurate.
So for noimod flag = 2,3 , we use the complicated expression.
This u can refer in BSIM3 manual.
Can anyone tell me a circuit, to simulate this noise and extract the Kf. Because not all foundries give Kf and Af. they give noia,noib,noic,Em,Ef.
Thanks in advance.
There is no need to enlighten me. I know, and in fact mentioned it in several of my previous posts to look up the kf and Af noia noib noibc Em Ef etc in the model file and look up the equations in the model guide.
IF YOU LOOK AT YOUR MODEL FILE AND THE VALUES FOR KF, AF, MOIA, NOIBM, EM, EF ARE NOT SET THEN IT IS
POINTLESS TO SIMULATE BECAUSE YOU NOT GET ANYTHING!! HOWEVER THEY ARE SET IS WHAT
ANY SIMULATION WILL GIVE YOU!
If noimod is set to 2 or 3 it will still use the parameters given in the model file. Again if they are not set, then you will get nothing.
Also as i said in my previous post you can simulate a common source fet driven by a voltage source on the gate and do a noise analysis. You will get the noise plot which, HOWEVER THE MODELS HAVE THE FLICKER NOISE PARAMETERS SETUP, will give you a noise you want. You can then correlate the slope and intercpet of the graph using simple maths to correlate back to the PARAMETERS IN THE MODEL FILE.
rgds,
aw