[SOLVED] automatic AD and AS in mosfet model

[ahmadagha23]

Hi
I want to use mosfet models in my circuit as following:
I define the lenght and width of mosfets when I define mosfets and HSPICE automatically define their AS an AD as AD=5*lambda+W and AS=10*lambda+W.

for example:
I write:
M1 D G 0 0 nhp L=1u W=1u
and HSPICE automatically use this definition:
M1 D G 0 0 nhp L=1u W=1u AD='.09u*5*1u' AS='.09u*5*1u'
+ PD='.09u*10+1u'
+ PS='.09u*10+1u'

Could you help me to use this feture of HSPICE?

 

[keith1200rs]

What version of Hspice are you using? Automatic calculation of the parameters you describe is normally done by the schematic capture program. Cadence does it and also Tanner using the 'callback' functions, I use SIMetrix and do it through templates.

Keith

 

[rfsystem]

You can avoid the calculation by either

1. The schematic entry system
or
2. The netlister calculating from schematic W&L


The bsim3v3 allows similar "prelayout" calculation by simply setting the HDIF&LDIF parameter.


HDIF, LDIF - In HSPICE this is the "length of heavily doped diffusion" and "length of lightly doped diffusion". They are used with the HSPICE ACM=2 MOS diode models, and there are no PSpice equivalents. HDIF and LDIF are not needed if AS, AD, PS, and PD are specified explicitly.

copied from here:

https://www.aboutspice.com/details-779[/url]

 

[ahmadagha23]

I use HSPICE A_2008.3.
Could I use a parameter or function or any other method in my .sp context to do that for me?
Could you please explain me how can I do it by Orcad CAPTURE from cadence?
Regards

 

[rfsystem]

I am not familar with Orcad but if you set the HDIF/LDIF in the model file you only need W and L in the netlist. The AS/AD/PS/PD are calculated for each instance at the simulation time.