LTSPICE Darlington model problem

Thread Starter

Veracohr

Joined Jan 3, 2011
772
Has anyone used a subcircuit model of a Darlington transistor in LTSPICE? I'm trying to incorporate the MPSA14 in a simulation because I have some, but it keeps saying the definition can't be found. This is the model I found:

Code:
* MPSA14 Darlington Transistor "macromodel" subcircuit
* created using Parts release 8.1 on 01/07/98 at 09:47
* Parts is an OrCAD product.
*
* connections:    Collector
*                 |  Base
*                 |  |  Emitter
*                 |  |  |
.SUBCKT MPSA14    1  2  3
*
Q1 1 2 4 Q1model
Q2 1 4 3 Q2model 2.873
D1 3 1 Dmodel
R1 2 4 200.0E6
R2 4 3 200.0E6
.MODEL Dmodel D
+ IS=10.00E-15 RS=1.000E-3 N=1 XTI=3
+  CJO=10.00E-21 VJ=1 M=.5 FC=.5
.MODEL Q1model NPN
+  IS=53.12E-15 BF=540.5 NF=1 VAF=100
+  IKF=.3345 ISE=77.22E-15 NE=1.366 BR=.6588
+  NR=1 VAR=100 IKR=2.639 ISC=907.4E-15
+  NC=2.069 RB=1.610
+  RE=0 RC=0 EG=1.110
+  CJE=12.06E-12 VJE=.7315 MJE=.3308 TF=500.0E-12
+  XTF=10 VTF=10 ITF=1 CJC=14.32E-12
+  VJC=.35 MJC=.2845 XCJC=.9 FC=.5
+  TR=500.0E-12
.MODEL Q2model NPN
+  IS=53.12E-15 BF=540.5 NF=1 VAF=100
+  IKF=.3345 ISE=77.22E-15 NE=1.366 BR=.6588
+  NR=1 VAR=100 IKR=2.639 ISC=907.4E-15
+  NC=2.069 RB=1.610
+  RE=0 RC=0 EG=1.110
+  CJE=12.06E-12 VJE=.7315 MJE=.3308 TF=500.0E-12
+  XTF=10 VTF=10 ITF=1 CJC=0
+  VJC=.35 MJC=.2845 XCJC=.9 FC=.5
+  TR=500.0E-12
.ENDS
There was one parameter I removed, "NK" (from the NPN models), because it's not in the LTSPICE User's Guide so I thought it might not be a valid parameter for LTSPICE and that it was the problem, but it didn't help.

I've added other subcircuit models just fine, opamp models like TL071 and NE532, but for some reason this Darlington transistor isn't working. Can anyone else use it successfully?
 

ericgibbs

Joined Jan 29, 2010
18,630
hi,
It works OK for me.
Did you first open the npndarlington using the F2 pop up selection box.? then change the name to MPSA14, then add inc MPSA14.mod or sub.?
E
 

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Thread Starter

Veracohr

Joined Jan 3, 2011
772
I didn't previously have an npndarlington symbol, but I made one. I don't know what's wrong with it, but it was the problem. I acquired a different symbol file and it works now, thanks.
 
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