Types of transistor models and differences between them

[extraord]

Re: Transistor Model

models are trade offs, they depend on your design goals. the deeper, the more accurate, but cost more time.

 

[Frank_H]

Re: Transistor Model

A lot of transistor models:
Physical models.
Empirical Models.
Black box models.
Neuronal model.

 

[mady79]

Re: Transistor Model

Inshort every foundry has its own models ,as a designer you just need to worry about the models supporting in subthreshold ,linear and saturation regions for Mos and models for other passive and active components .
Ask the modeling guys to check if the special things like montecarlo ,process corners,leakage,tolerance are included in the models or not befrore running various analysys .

Hope this answers ...

 

[vlsi_whiz]

Re: Transistor Model

Well, as mentioned above, there are a lot of models and each of them serve a different purpose.

The SPICE Level1 model is the IDEAL model. It closely resembles the IDEAL device behavior and is used for simulations and IDEAL modelling. This model cannot be used for commercial device/IC design. This is also true for the LEVEL2 and LEVEL3 models. The difference in these models is that each model will include more parameters for the transistor.

The commercial grade models are the BSIM3,BSIM4,MOS9,etc, from the standard foundaries. These models include a lot of information about the process paramaters, parasitics and other effects that are present in the IC fabrication process and very closely resemble the real world transistor.

If you open the model files that come with a simulator, you will find that each model will contain different information and the parameters also vary. For ideal device simulations, one should use the LEVEL1,LEVEL2 and LEVEL3 SPICE models, whereas, for IC design purposes you should always go for the BSIM3,BSIM4 , LEVEL49 SPICE model as these are more accurate.

 

[icfarmer]

Re: Transistor Model

which model is capable of predicting the intermodulation performance?

 

[leohart]

Transistor Model

Does bsim3 inculde Vgs<0(for nmos) situation?Why the Ids reaches about fractions of pA when the Vgs<0??!!It is a dpdm mixed signal process.
I fixed the Vds and sweep the Vgs from Vth to 0,the output is linear rather than exponential...What is going on...