:: LTspice ... inserting unknown SPICE models (NMOS example)

This is just a very quick 7 step run thru of how to find, grab spice files, insert and test it (in the case of NMOS)

first we identify our component, and find the SPICE file in the manufacturer website

in this case, our example NMOS is Infineon Technologies "irl40sc209"

the SPICE file can be found under the "simulation" tab

download and open the file using notepad or any text editor.

next open/create a test "platform" in LTspice in order to use/insert the NMOS SPICE file.

(this is my version of a NMOS test platform, copy this into a text editor, save as LTspice tester.asc or any filename. 

Version 4
SHEET 1 1696 2648
WIRE 304 -64 0 -64
WIRE 304 -32 304 -64
WIRE 304 64 304 48
WIRE 0 128 0 -64
WIRE 256 144 144 144
WIRE 144 160 144 144
WIRE 304 192 304 160
WIRE 0 288 0 208
WIRE 32 288 32 256
WIRE 32 288 0 288
WIRE 144 288 144 240
WIRE 144 288 32 288
WIRE 304 288 304 272
WIRE 304 288 144 288
FLAG 32 256 0
FLAG 144 144 VGS
SYMBOL voltage 0 112 R0
WINDOW 123 0 0 Left 2
WINDOW 39 24 114 Left 2
SYMATTR InstName V1
SYMATTR Value 10
SYMBOL voltage 144 144 R0
WINDOW 3 -75 102 Left 2
SYMATTR InstName V2
SYMATTR Value PWL(0 0 2 5 4 5 6 10 8 10 12 0)
SYMBOL res 288 176 R0
SYMATTR InstName R3
SYMATTR Value 1f
SYMBOL res 320 64 R180
WINDOW 0 36 76 Left 2
WINDOW 3 36 40 Left 2
SYMATTR InstName R5
SYMATTR Value 1f
SYMBOL nmos 256 64 R0
SYMATTR InstName M1
TEXT -24 32 VRight 2 !.tran 0 12 0 startup

 

)

my test platform should look roughly like this



 
open a SPICE .op panel and copy in the irl40sc209 NMOS SPICE data (note use smallest font size, the text chunk is huge). by default, the pins are matched DGS and no other modification to the irl40sc209 text is required.

 
now, modify the LTspice NMOS component by "CTRL R-click", to open the "component attribute editor". change the "Prefix" from MN to X, and change the Value from NMOS to irl40sc209.

when you run the simulation and view the Vgs and I(R5), you should be able to determine that the SPICE data have executed correctly.

fun tip : it is possible to view the RDSon condition by using R= V/I. which is the Vds/I(R5). by shrinking the run time, the simulation will show that the minimum RDSon is about 0.8 milli-ohm.

good luck n have fun!

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