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" Floating point computation failed during matrix solution" reported from TI pSpice

Peng Liu50174
Expert 1480 points
Other Parts Discussed in Thread: LM358, TPS40210, LM358LV, LM318, INA169

Hi, TI Expert,

Here is one problem needs your help.

I inserted LM358 into one transient simulation project using TI pSpice, however simulation failed with error "Floating point computation failed during matrix solution"

When changed the GMIN to 1.0E-10, this error disappeared, but "RON or ROFF greater than 1/GMIN for VSWITCH model" was reported.

I noticed <Number> with LM358 symbol, but I could not change its value. Not sure if the error is related to this?

The project was attached. 

Thanks,

TPS40210_PSPICE_TRANS.zip

  • 0
    TI__Mastermind 22941 points

    Hey Peng,

    Could you confirm that you were able to get the simulation running without the op amp because I'm currently unable to get the simulation to run without the op amp.

    Additionally the library you are using is out of date, if you could update your library to the most recent version, that may help with convergence, as we have updated many of our models to aide with convergence.

    It doesn't look like the issue is with the LM358LV.

    Best,
    Jerry

  • 0 in reply to Jerry Madalvanos
    Expert 1480 points

    Hi, Jerry,

    When I replace LM358LV with another OP such as LM318, then simulation can run.

    Peng,

  • 0 in reply to Peng Liu50174
    TI__Genius 17787 points

    Hey Peng, 

    Looks like the op amp you are using is from an out of date library. When I place the LM358LV from my (more up to date) library it shows up without <Number>
    Here is a side by side: Left is the one in the project originally and right is the one I placed. 

    Under Help > TI Models, Products, Application Support, you will be able to see which library version the program is running: 

    I recommend allowing PSpice to automatically update libraries when the program prompts as you first start up. Here is a FAQ. 

    "TI releases updates in the library database and these updates are prompted to the user in PSpice for TI. PSpice for TI automatically checks for library updates on every invocation and if updates are available, it processes the same. Once successfully processed, on next launch of PSpice for TI you are notified about the updates through the following message. You will need to launch PSpice for TI from time to time to check for updates. Orcad will see the library updates that are added by PSpice for TI.
    "

    When this dialog box comes up, I would select "Always apply library updates." and Yes. 

    All the best,
    Carolina

  • 0 in reply to Caro Walter
    TI__Mastermind 22941 points

    Hey Peng,

    I tried to run the simulation with LM318 and got convergence issues with INA169. I agree with Caro that the library is out of date and you need to update it like I also suggested above. However, I do not believe the issue is solely in the op amp.

    Best,
    Jerry