LTspice, Warning node is floating

[Vinasse]

Hello,

As my first question was answered so quickly, I can't resist to put another one.

Still trying to simulate a Flyback converter with a Viper16L from ST, when I'm running the simulation multiple warning appear in the log file, "Warning node Viper16L (D100) is floating" except that all the "pins" of the Viper16L are connected. I don't understand, maybe it is something inside of the component ?

It would be really nice if someone could help me on this.

Have a nice day !

[Harald Kapp]Atttachments deleted upon request by op.

 

[eetech00]

Hello,

As my first question was answered so quickly, I can't resist to put another one.

Still trying to simulate a Flyback converter with a Viper16L from ST, when I'm running the simulation multiple warning appear in the log file, "Warning node Viper16L (D100) is floating" except that all the "pins" of the Viper16L are connected. I don't understand, maybe it is something inside of the component ?

It would be really nice if someone could help me on this.

Have a nice day !

Post an image of the schematic and the schematic.asc file

 

[Vinasse]

Post an image of the schematic and the schematic.asc file

Here a capture of the schematic.

[Harald Kapp]Atttachments deleted upon request by op.

 

[duke37]

I cannot read the schematic properly but it looks as if there are two capacitors in series, bottom left. There is no DC connection to the junction, use a 100M resistor across one of them.

 

[Martaine2005]

@duke37
If you left click on the image and then Right click, then choose View image, it will display larger. Then Right click again and it's even bigger..
I only found that out the other day.

Martin

 

[duke37]

I found that I had to tick to put into original location before I could bodge it.
I was wrong there are no capacitors there.

There is however a floating wire connected to V108A and labeled 3.3V

 

[Martaine2005]

Blimey, eyes like a hawk now!!!
Well spotted.
Is the 12v , middle right hand side floating too?

EDIT: I just tried that with only text labels and didn't get an error.
Martin

 

[Arouse1973]

I found that I had to tick to put into original location before I could bodge it.
I was wrong there are no capacitors there.

There is however a floating wire connected to V108A and labeled 3.3V

Hi Trevor
That's just a power net label I think, how is it floating?
Adam

 

[Martaine2005]

Just found that out Adam...

Martin

 

[Arouse1973]

Can you post the .asc file and library files for the non standard parts and I'll have a look. You can zip them up and add them as a file.
Adam

 

[eetech00]

Here a capture of the schematic.

One problem is the Mosfet model. CTL+RHT-CLK on symbol, then change the "prefix" attribute to "X", without quotes. Save schematic, close, re-open.

There is an additional problem with the VIPER model.
Zip up the model files (.mod and .asy for each) and the LTspice .asc file so we can troubleshoot for you.

 

[Vinasse]

First I would like to say thank you to all of you, I never thought that so many people would want to help me and so quickly.

So now to answer to all of your questions.
Eetech00 : The value of the attribute prefixe for the MOSFET is already X. And yes I think the main problem comes from the Viper model.
Martaine2005, Arouse1973 and Duke37 : The two power labels are connected to each other right ? 3.3V with 3.3V and 12V with 12V, maybe I did something wrong.

Anyway here is the .asc and all the models I used for the diodes, the MOSFET and the Viper16L. For the diodes I added them to the standard.dio in the LTspiceIV\lib\cmp maybe I did something wrong.

Thanks a lot again to all.

[Harald Kapp] attachment deleted upon request by op.

 

[Martaine2005]

Martaine2005, Arouse1973 and Duke37 : The two power labels are connected to each other right ? 3.3V with 3.3V and 12V with 12V, maybe I did something wrong.

You did nothing wrong, they are the text net labels. I tried it out and it does indeed work correctly.
I am only just getting into LTspice, I normally get the 'error' by forgetting to label it! So I just connect them all.

Martin

 

[Arouse1973]

First I would like to say thank you to all of you, I never thought that so many people would want to help me and so quickly.

So now to answer to all of your questions.
Eetech00 : The value of the attribute prefixe for the MOSFET is already X. And yes I think the main problem comes from the Viper model.
Martaine2005, Arouse1973 and Duke37 : The two power labels are connected to each other right ? 3.3V with 3.3V and 12V with 12V, maybe I did something wrong.

Anyway here is the .asc and all the models I used for the diodes, the MOSFET and the Viper16L. For the diodes I added them to the standard.dio in the LTspiceIV\lib\cmp maybe I did something wrong.

Thanks a lot again to all.

Just woke up, got a few things to do. I will have a look later, if @Harald Kapp doesnt beat me to it
Adam

 

[Harald Kapp]

Don't worry, Adam, not today - too busy.
I triedd hortly to simulate the circuit, but I'd have to include the unknown components into the lib or add a new lib.

@Vinasse : have you had a look into the ressources section? There I posted a ressource on LTSPICE error messages and some tips how to remedy them.

 

[Vinasse]

Don't worry, Adam, not today - too busy.
I triedd hortly to simulate the circuit, but I'd have to include the unknown components into the lib or add a new lib.

@Vinasse : have you had a look into the ressources section? There I posted a ressource on LTSPICE error messages and some tips how to remedy them.

Hello Harald,

So I checked your post, and I don't think I have any of these errors.

I do have 3 GND but I don't think it is an error, they need to be connected.

 

[Vinasse]

One more question, do I need to put all the attribute prefix to X for all the diode models that I added ?

 

[eetech00]

One more question, do I need to put all the attribute prefix to X for all the diode models that I added ?

Any diode symbol that is a defined by a .subckt should have its prefix changed to X.

BTW
Diode V104 does not have a value specified...

 

[eetech00]

The VIPER16 model is encrypted. You will have to talk to the model supplier to work out why its not working, unless they will provide you an unencrypted model file. Then we might be able to help.

eT

 

[Vinasse]

Any diode symbol that is a defined by a .subckt should have its prefix changed to X.

BTW
Diode V104 does not have a value specified...

Ok thanks for the prefix, I will change them, and yes the V104 has no value, I am still waiting for a model from ST Micro. I can't find it on the web (STTH108).