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Issue including z diode model

Message 1 of 2
435 Views, 1 Reply

Issue including z diode model

Hi. I am trying to simulate a circuit using Fusion 360. My circuit incorporates a zener diode (namely bzx84c5v1). 

I found a spice model for this zener diode online:


*src=BZX84C5V1;DI_BZX84C5V1;Diodes;Zener <=10V; 5.10V  0.350W   Diodes Inc. 
*        Terminals    A   K
D1 1 2 DF
DZ 3 1 DR
VZ 2 3 2.74
.MODEL DF D ( IS=28.3p RS=33.9 N=1.10
+ CJO=66.2p VJ=0.750 M=0.330 TT=50.1n )
.MODEL DR D ( IS=5.65f RS=44.5 N=3.00 )


I am no expert on SPICE and I don't really know how this work or even if it is correct or not. However I don't even have the opportunity to find out by myself since I can't run the simulation. I am getting this error:
missing subckt.png

I had just saved the mapping and model but still am unable to simulate. I didn't find anyone having this issue in the forum but maybe I just didn't use the right search keywords.

Also, maybe I'm just really dumb but I cannot for the life of me find an independent voltage source in the Add Part menu. I need it for the DC Sweep simulation, but it's just nowhere to be found.


Any help regarding either of these issues would be much appreciated.

Message 2 of 2
in reply to: demariano95

Hi @demariano95 

I hope you are doing well!

For your questions,  here are my answers:

1. For 'Missing SUBCKT...' warning message, can you please try to put the mdl file in the ~/Documents/Fusion 360/spice directory? Simulation will look there for additional models.

2. For fail to find the independent voltage source, you can try the following steps:

In Add Part Dialog -> Click Open Library Manager icon -> In Library Manager dialog -> Switch tab to Available -> Search with 'ngspice' key word to find the ngspice-simulation library -> Select it and Click Use -> Then you can find the independent voltage source in the ngspice-simulation library

Screen Shot 2020-09-18 at 3.23.34 PM.png

Screen Shot 2020-09-18 at 3.30.22 PM.png

I hope my answers can solve your problem. If you still have other problems, please leave your comment, thanks!



Panpan Fan

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