Eliminate external pin in SPICE netlist

Question

I'm working with a SPICE model of a MOSFET that provides a fourth pin for setting the device temperature (driving the pin with a voltage in simulation sets the temperature). However, I don't plan on playing with the temperature in simulation and the extra pin means I'm not able to use a standard MOSFET symbol, which is annoying.

I'd like to eliminate the external temperature pin and set the voltage of that node internally to 25 V. What would I have to modify in the following netlist? I'm thinking I would have to add the directive:

VTEMP 50 0 25

in the section labelled *TEMP SECTION, but I'm not sure if this is correct.

*FDV301N at Temp. Electrical Model
*-------------------------------------
.SUBCKT FDV301N 20 10 30 50
*20=DRAIN 10=GATE 30=SOURCE 50=VTEMP
Rg 10 11x 1
Rdu 12x 1 1u
M1 2 1 4x 4x DMOS L=1u W=1u
.MODEL DMOS NMOS(VTO=0.82 KP=4.12E-1
+THETA=0.25 VMAX=1.5E5 LEVEL=3)
Cgs 1 5x 8.5p
Rd 20 4 0.7
Dds 5x 4 DDS
.MODEL DDS D(M=3.61E-1 VJ=8.34E-1 CJO=12.08p)
Dbody 5x 20 DBODY
.MODEL DBODY D(IS=7.78E-9 N=1.946325 RS=0.023193 TT=15.97n)
Ra 4 2 0.7
Rs 5x 5 0.5m
Ls 5 30 0.5n
M2 1 8 6 6 INTER
E2 8 6 4 1 2
.MODEL INTER NMOS(VTO=0 KP=10 LEVEL=1)
Cgdmax 7 4 75p
Rcgd 7 4 10meg
Dgd 6 4 DGD
Rdgd 6 4 10meg
.MODEL DGD D(M=0.270882 VJ=4.24E-6 CJO=75p)
M3 7 9 1 1 INTER
E3 9 1 4 1 -2
*ZX SECTION
EOUT 4x 6x poly(2) (1x,0) (3x,0) 0 0 0 0 1
FCOPY 0 3x VSENSE 1
RIN 1x 0 1G
VSENSE 6x 5x 0
RREF 3x 0 10m
*TEMP SECTION
ED 101 0 VALUE {V(50,100)}
VAMB 100 0 25
EKP 1x 0 101 0 2.2
*VTO TEMP SECTION
EVTO 102 0 101 0 .003
EVT 12x 11x 102 0 1
*DIODE THEMO BREAKDOWN SECTION
EBL VB1 VB2 101 0 .08
VBLK VB2 0 25
D 20 DB1 DBLK
.MODEL DBLK D(IS=1E-14 CJO=.1p RS=.1)
EDB DB1 0 VB1 0 1
.ENDS FDV301N
*FDV301N (Rev.B1) 5/15/02 **ST
*FDV301N (Rev.B2) 10/1/13

Answer 1

That will do, but you'll also have to take care of the pins, by deleting or commenting out 50 in:

.SUBCKT FDV301N 20 10 30 50

You could also make that a parameter, by transforming Vtemp into:

Vtemp 50 0 {temperature}

(or some other naming, but try to avoid temp, it's a keyword in SPICE) and adding:

.param temperature=25

With this, whenever you place the transistor in the schematic, you can add temperature={x} and even use a .STEP directive.