Because of the Thanksgiving holiday in the U.S., TI E2E™ design support forum responses may be delayed from November 25 through December 2. Thank you for your patience.

  • State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 47 subscribers
  • Views 262 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Original question:

LM224A: The simulation does not converge

LM2902: Convergence Issue when simulating with single supply

Derek Belsky
Prodigy 20 points
Part Number: LM2902

The following convergence error message comes up when I tried to model the LMX24_LM2902 as a single supply op amp.

INFO(ORPSIM-16594): To improve Pseudotransient Convergence and Performance, set following options to relax stabilization criteria for capacitor currents and inductor voltages: PTRANABSTOL=1e-5, PTRANVNTOL=1e-4

This issue was seen in a similar thread about three years ago but looks like the model still has the issue. 

Here is a snippet of my circuit that I ran a bias point simulation for:



As mentioned in the other thread, the model works with dual supply where both voltages are the same. I was wondering if there was a version that had the fix. I can use TINA simulation tool but I just wanted to bring attention to this as it still seems to be a problem. 

  • +1
    TI__Mastermind 28476 points

    Hey Derek,

    Could you right-click the model and click "view PSpice Model" then share a screenshot of the header? It should look similar to the below.

    A while ago we updated a lot of our models to converge better in single supply, but it seems that this one may have slipped through the cracks (your screenshot will confirm this). Thanks for bringing it to our attention!

    There are some other things in the model that don't simulate well in PSpice for TI but are a necessary inclusion for this model. One of them is the Sinking current claw curve. Unfortunately there isn't much we can do about this function.

    There is a new one coming soon where we will fix the single supply convergence issue. If you want to edit the netlist, C1 in the schematic is listed as 1 farad. If you change this value from 1 to 10n this should help your circuit converge in single supply.

    Best,
    Jerry

  • 0
    Prodigy 20 points

    Yes my header matches the header you sent. 




    I was able to change the netlist file and I also relaxed the auto convergence parameters to the following:



    After that I was able to simulate for several different configurations successfully. 

    Thanks!