[SOLVED] BSIM4 small-signal model

Hello
I need the BSIM4 small-signal equivalent circuit , I am looking for it but can't find it , does somebody have it ??

thank you in advance

The Berkley BSIM4 manual is here: www.eigroup.org/cmc/cmos/b4manual.pdf does that help?

Keith.

Thank you for the reply Keith
Actually the manual I have it and I am reading it , what will help me is a schematic that represents the equivalent small-signal circuit of the transistor.

I have this document as well - does that help? I cannot find out where I got it from, but it is open source.

Keith.

thank you Keith,
yes it helped me a little bit
if you can see in slide 10 in the powepoint you posted there is a transistor , and this transistor is a black box.
actually to give you an idea, I have simulated a single transistor
here is my schematic(single.jpg)



and I want to make a circuit with passive components, vccs , etc that gives me the same frequency response as the transitor , that's why I am looking for a schematic of the BSIM4 equivalent smal;l-signal circuit .

I just found a schematic on the net , I will simualte it and see what it gives (model.jpg)

I hope it makes sense

I have had another search and cannot find a diagram for the internal model anywhere. I guess it is implied in the BSIM4 manual but it is a long manual to read to try to extract a few useful bits, I am afraid.

Keith.

Yes indeed Keith, no way one needs to read the manual
thank you for the help

The BSIM4 model is essentially a range of increments, corrections, and adjustments to previous SPICE models; the closest such model (unsurprisingly) is BSIM3. Many of the adjustments apply only to the equations, so they don't effect the schematic*. Others, such as leaks, series resistances, stray capacitances, etc. can vary between regions and model implementations, so a single schematic that includes all versions of these would become unbelievably cluttered.
I agree that it would be really lovely to have a manual that included a simple schematic showing how each individual addition impacted the basic model, but I do not know of anything like that.
The best I have seen is the sequence of schematics in William Liu's book "MOSFET models for SPICE simulation..."
I hope this (late contribution) will help somebody

*To my mind the largest BSIM improvement is the change to charge-based models - imperfect as the implementations may have been in some cases.