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TPS38-Q1: About PSpice Model

Part Number: TPS38-Q1
Other Parts Discussed in Thread: TPS38, PSPICE-FOR-TI

Hello Expert,

Our customer will use TPS38-Q1 which is TPS38A010122DSKRQ1.

So they tried to simulate it w/ SNVMC72.ZIP (277 KB) - PSpice Model.

But there is error issue which is undefined error like below captured image.

Do you know what's the root cause? or Could you please give us resolution and guide?

Is there a PSpice model only for TPS38A010122DSKRQ1 device?

I'm looking forward to receiving your feedback asap.

Best regards,


  • Hi MIchael,

    Thank you for your question. Is this simulated using PSpiceforTI or independent ORCAD? Also what version are they using?


  • Hi Jesse,

    Here is what you requested

    * ORCAD (Ver 17.4)

    Pls check it and let me know.

    Thanks & Best regards,


  • Hi Michael,

    I do see the issue when my ORCAD is not connected my internal TI library, I will look into this more.

    For this current customer issue, I would suggest to use PspiceforTI to run the simulation for the TPS38.


  • Hi Jesse,

    I have recommended to my customer to use PSPICE-FOR-TI.

    So they agreed.

    Here is additional questions from our customer.

    They have a plan to use TPS38A010122DSKRQ1.

    Could you please give me answer about each item after review?

    1. How do I set for Part Properties for PSPICE Model?

        I need to set the Pspice Model Property, and could you check whether the settings below are correct or not for TPS38A010122DSKRQ1?

        What does it means "1" or "0" for CH1_INPUT or CH2_INPUT?

        * Setting

          CH1_INPUT = 1, CH1_OUTPUT = 0, CH2_INPUT = 1, CH2_OUTPUT = 0, HYS1 = 0.02, HYS2 = 0.02, VTH1 = 0.8, VTH2 = 0.8

    2. Do I have to write 0.02 in HYS1, HYS2 if hysteresis is 2%?

        Is it right?

    3. When I set like below, Simulation results confirm that the RESET2 output is affected by the SENSE1 voltage level.

        In case, how does this symptom happen? could you check whether the error is caused by a missing part in the model properties.

        * Setting

          CH1_INPUT = 1, CH1_OUTPUT = 0, CH2_INPUT = 1, CH2_OUTPUT = 0, HYS1 = 0.02, HYS2 = 0.02, VTH1 = 0.8, VTH2 = 0.8

        * Test



    4. About Hysteresis Voltage Level.

    As shown in the Timing picture below, when a 3.3V constant voltage is applied to VDD, RESET#1 and RESET#2 signals are output according to the V2 voltage hysteresis level (14.5V / 13.25V).

    As shown in the Pspice for TI circuit diagram below, we want to set the hysteresis level 1.25V (14.5V-13.25V=1.25V) to suit the user definition using NMOS.

    When configuring the circuit, it was confirmed that hysteresis operation is possible, but a different hysteresis level than intended occurs.

    Therefore, we request a hysteresis circuit suitable for user definition recommended by TI and calculation data for the resistance (R1, R5 below) suitable for the corresponding hysteresis level.

    (Considering the hysteresis 2% Tol, R1 & R5 were adjusted, but a different hysteresis level than intended was confirmed, and RESET#2 intentionally delayed it.)

    Best regards,


  • Hi Michael,

    The device parameter for this model is already preset for the TPS38A010122. You should not have to change the parameters for the testing that you have described. If the customer needs to adjust the hysteresis of the device, we have a calculator and an example circuit located in the link below.


  • Hi Jesse,

    Thanks for your feedback.

    I need your reply to each question on my above thread for our customer and me.

    I don't understand about your comment that "The device parameter for this model is already preset for the TPS38A010122"

    When I checked the library parameter of TPS38-Q1 PSpice Model, this is different from TPS38A010122.

    Do I misunderstanding?

    We need more your kind explanation.

    Best regards,


  • Hi Micheal,

    Thank you for pointing this issue out, I will have to look into this one as well. 

    The parameter settings is listed below.