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Help working with a Spice model in MultiSim?

I have a spice model (txt) of an NMOS I'm trying to bring into MultiSim (file is attached).  I have never worked with spice models before, so this is a first for me.

I followed the instructions I found here:
http://digital.ni.com/public.nsf/allkb/85281067A82F9DE186257AEF00654728


However, I have a few questions:


1.  I only need the NMOS.  So I copied everything from the top of the file until:

****************not used +CBD    =0.000e+00 CBS    =0.000e+00 IS     =0.000e+00
+MJ     =3.400e-01 N      =1.000e+00 MJSW   =2.300e-01
+PB     =6.900e-01 TT     =0.000e+00
+PBSW   =6.900e-01
* ---------------------------------------------------------------------


I did NOT copy this part:

.subckt PM D G S B
+params: W=10u L=1u
M1 D G S B PM L={L} W={W} AS={2u*W} PS={2*(2u+W)} AD={2u*W} PD={2*(2u+W)}
.ends


Was that correct?  Or does that section still belong to the NMOS device?



2.  As part of the import process, I was supposed to verify the pin order.  But I had no way of knowing for certain whether the pin order was correct or not.  I used the virtual model, and it had a line of text rather than the table my imported component had.  How can I tell what the correct pin order is?  And what's the best way to correct it now?  Should I just delete the component from the User DB and start over?


3.  Once I place an instance of this component on the schematic, how do I edit the gate length and width?  Specifically for just that instance, because I will place several of these, and they won't all have the same length and width.



Thanks!

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Hi Doven,

 

1.  You are correct, the "PBSW" is the last parameter defined in this NMOS model.

+PBSW   =6.900e-01
* --------------------------------------------------

 

2.  You can look up the NMOS in a SPICE manual it will tell you the pin out.  If you look at the PMOS model in the text file, you can tell the pin order from the sub-circuit statement.  Pin order starts from left to right, so D is pin 1.

.subckt PM D G S B 

 


3.  If you want to add length and width to the model, create a sub-ciruit similar to the PMOS model in the text file. You need to add these lines:   

 

.subckt NM D G S B

M1 D G S B NM L=0.001 W=0.001

* Paste the NMOS model betwen these lines.

.ends NM

 

 

Tien P.

National Instruments
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Hi how do i correct this.

i copy the same schmatic file that the spice file is attached

 

 

SEE ATTACHED

 

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