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LTSpice LM13700 Simulation Error

Yoa01

Jun 18, 2012
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Jun 18, 2012
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Hello all,

So I am trying to figure out how to properly simulate LM13700's without blowing up yet another chip (I've gone through 3 already - these get expensive!). I have LTSpice, so I figured I would grab an .asy of the LM13700 (this one), which I pasted into Notepad++ and saved as LM13700.asy in the lib/sym folder, and try it out.

I built the Ramp/Pulse VCO schematic from the datasheet in LTSpice, but when I tried to run it I got this error:

"Unknown subcircuit called in:
xu1 n002 nc_01 0 n007 n008 n010 n008 n004 n005 lm13700/ns"

Any ideas on how to fix this? If it helps (read: if I need to make an entirely new .asy), I have TI's SPICE model (http://www.ti.com/litv/zip/snom267) and know enough of SPICE programming to make things work.

Thanks in advance.
 

Harald Kapp

Moderator
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Nov 17, 2011
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The asy is only a grphic representation of the LM13700. You need to tell LTSPICE to use the model (subcircuit), or else it is unknown to LTSPICE.

Here is a tutorial on how to integrate a subcircuit (the .MOD file) into an LTSPCE simulation.
 

Yoa01

Jun 18, 2012
214
Joined
Jun 18, 2012
Messages
214
I thank you for that link. Though it directly did not help (call me stupid haha), it did lead me to find an alternate solution.

For the curious, if you right-click the .subckt statement and click 'Create Model', LTSpice will generate a standard DIP-style IC that you can then edit.
 
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