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TPS50601A-SP: Issues running TPS50601A-SP in SPICE

Part Number: TPS50601A-SP

I'd like to design PoL converters for spaceflight applications and am particularly interested in designing with the TPS50601A-SP. I've downloaded the available PSPICE model file from the Texas Instruments website and I have imported them directly into SIMetrix for analysis. SIMetrix was unable to assign pins to the package, so I manually configured each pin to match the pin order in accordance to the package information displayed in the datasheet.

When running the example simulation, I'm receiving a floating node error both in SIMetrix and LTSpice. The issue seems to be with the PWPD pin, as I'm able to get the simulation running without grounding PWPD. When PWPD isn't grounded, the output voltage is reading 3.4V, rather than the circuit configured 2.5V output voltage I should be reading. The circuit was configured using the Texas Instruments provided example used in one of the Excel calculators. Any advice in getting this simulation to properly run would be greatly appreciated.

  • Hi,

    Let me loop in our modeling expert to see if she has any ideas.



  • Hi Natan,

    Thank you for all of the detailed information and screenshots you have provided regarding the issue you're seeing. It greatly helps with troubleshooting.

    Based on your observations regarding the PWPD pin, it sounds like the issue may be due to the rearrangement of the pins. The PWPD pin is not connected to anything internally in the model so it shouldn't have any impact on simulations. Can you try setting up your schematic using an unedited version of the part symbol and see if that resolves the issue? This will tell us if the problem is being caused by something that got mixed up when you edited the part symbol or if the issue is stemming from another cause. 



  • Thanks for the response Sarah,

    A coworker at Raytheon provided me the contact information for a couple TI representatives and I was able to confirm with them yesterday that I do reach steady-state 2.5V output voltage with the unedited version. I'm awaiting to hear back from them, but I did also ask if Texas Instruments does provide assistance in configuring the pins for PSPICE schematic capturing purposes? I believe I had used the proper pin order and arranged each pin accordingly in the software. My intent is to arrange the package in a way resembling the pin layout that I have for the TPS50601A-SP in Xpedition AMS Design. 

    Thanks again,


  • Hi Nate,

    Great, I'm glad it's working!

    You're asking whether there is any information about how to edit the symbol in PSpice so that you can arrange the pins to resemble the image above, correct? If that's the case, you can utilize this model User Guide starting from Step 11 on page 7. This document is for a different model than the one you're using, but contains information about setting up schematics and simulations in PSpice that would be generally applicable to other models.