Simulation setup of a simple circuit not working

Simulation setup of a simple circuit not working

waltercFKW73
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Message 1 of 5

Simulation setup of a simple circuit not working

waltercFKW73
Contributor
Contributor

I have a very simple current loop to voltage converter circuit (schematic attached) and I want to run a simulation on it before I order the board.  I thought this would be a circuit to learn on but I can't figure out what is wrong with this.  Any help would be appreciated.

 

The op amp V+ is 1.8V. V- is ground.   The current source should vary from 4ma to 20 ma and the V1 DC source is 24V (24 v 4-20ma current loop).  I don't use the second section of the op amp.  I really don't know what I am doing wrong.  

 

When I click Simulate, I get this output

 

Too few parameters for subcircuit type "tlv9052_dual" (instance: xx_ic1)

Simulation interrupted due to error!

 

Note: No ".plot", ".print", or ".fourier" lines; no simulations run

 

Note: Compatibility modes selected: ps a

 

 

Circuit: * spicenetlist

 

I've also attached the node list.

 

 

Thanks in advance.

 

waltercFKW73_0-1750456169591.png

 

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Message 2 of 5

jorge_garcia
Autodesk
Autodesk

Hello @waltercFKW73 ,

 

I hope you're doing well. The first thing you need to do is make sure that all pins are connected to something. The simulator in Fusion does not allow for any pins to be unconnected. For things you intend to have floating you can just connect them to really high value resistors.

 

Additionally feel free to use suffixes like k,u,Meg, etc. so that you don't have to put so many zeroes.

 

Let me know if there's anything else I can do for you.

 

Best Regards,



Jorge Garcia
​Product Support Specialist for Fusion 360 and EAGLE

Kudos are much appreciated if the information I have shared is helpful to you and/or others.

Did this resolve your issue? Please accept it "As a Solution" so others may benefit from it.
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waltercFKW73
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Contributor

Thanks @jorge_garcia!  Once I get back to this I'll double check.

 

I have tried to enter different suffixes but it wouldn't accept them.  I may not have done it right so share how to do that pleas.

 

Also, does having nets in the schematic using the default N$# (as in N$3) nomenclature and the simulation netlist showing N_# cause any issues?

 

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Message 4 of 5

jorge_garcia
Autodesk
Autodesk

Hi @waltercFKW73 ,

 

I hope you're doing well. When you enter values just add it in, so for example 10k, 1Meg, 1u all work.

Default net names(N$#) do not create any problems, you don't have to explicitly name every single net. They just need to exist.

 

Let me know if there's anything else I can do for you.

 

Best Regards,



Jorge Garcia
​Product Support Specialist for Fusion 360 and EAGLE

Kudos are much appreciated if the information I have shared is helpful to you and/or others.

Did this resolve your issue? Please accept it "As a Solution" so others may benefit from it.
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Message 5 of 5

waltercFKW73
Contributor
Contributor

@jorge_garcia  I finally had a minute to work on this.  The problem was that pin 7 (OUT2) of the IC was not connected to anything  because we don't use that second op amp in this circuit.  I rigged it by connecting to a 10K resistor and the resistor to ground.   I cleaned up a couple of straggler lines that would normally go to an off board connector too.   The simulation ran!!!  Woohoo!  Thank you so much! Of course, I took a chance that the circuit and board works as designed and ordered the PCB before running the simulation but all worked out ok. it's not an expensive board.

 

Thank you.  You are the best!

 

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