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Guest

Dear All:

I'm working on a mos mismatch investigation for a circuit at cadence.
But I can't get how to do mismatch set for chennel length or width. In
statistics file, there's only place for parameters in model. If I have
size mismatch, how can I put they in statistics file? By the way, is
there anyone know how to deal with correlate factor between W and L at
same device?

Thank you very much.

Huang

Andrew Beckett · Guest

On 17 Sep 2005 03:49:59 -0700, hb_huang@hotmail.com wrote:

Guest

Hi Andrew:

Thanks for reply. I've gone through with Don's paper from
designers-guide and get some ideas. For some parameters from BSIM model
or other model (sub cuicuit), Don's method worked great, like: Vth0,
tox, or rshsp. However, one of my main questions is still exist. It's
main regarding to geometrical mismatch issue. I don't know if there
is/are parameters at BSIM MOS model for width and length scaling
factor. At Don's paper, he introduced such factors XRSPbfac and
XRSPafac by including a inline sub circuit of resistor. By this mean,
do I need to do same thing for MOS?

Also, generally I would use Vth0, tox for MOS process and mismatch
variation, if it's enough for normal purpose or not?

Regards

Huang

okguy · Guest

Take care of the parameter : m
You cannot acces it in the models.
Your mismatch varies with the square root of W.
But W varies with m.
Let's try a transistor 9/1 and another 3*3/1.

OkGuy

Guest

Very interesting, OkyGuy. Would you mind make it more clearly? If I
can't access to m, how can I use it as a parameter in statistics.scs
file? As a mater of fact, MC simulator at Cadence could not recognize
my m at statistics.scs file. Thanks.

Regards

Vincent

okguy · Guest

You can find more info from that post :
http://www.talkaboutcad.com/group/comp.cad.cadence/messages/17475.html

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