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TPS53316 Tina-TI Simulation Problem

Siyu He
Expert 1040 points
Other Parts Discussed in Thread: TPS53316, TINA-TI

Hi all,

I was trying to simulate the TPS53316 in Tina-TI and it turns the circuit did not work. The following pictures are the schematic and the waveform. It seems like the TPS53316 did nor operate in simulation.

The attachment contains the spice model and simulation files. Please help me diagnose the problem.

He, SiyuTPS53316 Simulation.zip

  • 0
    TI__Mastermind 41310 points

    Siyu,

    The simulation should begin to work if you change the input from a fixed voltage source to a voltage waveform and use a rise time of 100n. I am not convinced that the design will function, but the simulation does begin to switch at about 200us. Did you use WEBENCH® to design this circuit?

    Please see your modified circuit below:

    TPS53316EVM Simple_up.TSC

  • 0 in reply to Britt Brooks - Online Design Tools
    Expert 1040 points
    Hi Britt,

    Thanks for your reply. The schematic was copied from the datasheet and the EVM application note. The purpose of simulation was to compare with the measurement on EVM. Besides, I tried to short the FB pin to ground, the SW only show switching of several cycles.
    I will try the modified circuit as soon as I get back to my laptop.

    He, Siyu
  • 0 in reply to Britt Brooks - Online Design Tools
    Expert 1040 points

    Hi Britt,

    I tried the modified circuit, the TPS53316 still operated for just a short time. From the following waveform, I am wondering is it due to the oscillating inductor current triggered the OCP? As the cursor b indicates, the peak current is over 12A, the OCP is about 5A.

    He, Siyu

  • 0 in reply to Britt Brooks - Online Design Tools
    Expert 1040 points

    Hi Britt,

    It seems like the main reason is the feedback loop. I changed the compensator values from that on datasheet to the values on EVM application note, the simulation works now. I am wondering why the input voltage has to be an step source?

  • 0 in reply to Siyu He
    TI__Mastermind 41310 points

    Siyu,

    I noticed that the schematic did not seem to match the EVM guide or the datasheet example either. The datasheet design may not be correct, in that the schematic shows a Vout=1.2V, but the description states a 3.3V design. This was a little concerning to me. I did not originally check the datasheet, only the EVM guide and its circuitry as this is the same circuit that we used when we released the TINA-TI simulation.

    BTW, the input does not always have to be a pulsed source. Many of the applications use the voltage supply or battery and have no issues. My experiences have shown that TINA-TI seems to prefer using the pulsed source (probably due to the way it internally handles pulsed sources vs. how it handles batteries or voltage sources). I, also, prefer to use the pulsed source so that I can control the rise and fall times of my applied signals and can tailor the source to my needs for the best solution. In this case, it appeared to me that TINA-TI performed better with the pulsed source.

    Please remember that a simulator is a linear equation solver and really has no idea what you are trying to do. It is simply following a set of rules to come to a solution of the linear problem given by the circuit you have provided. If the rules change, the solution may change as well. That is why we have convergence parameters to allow the simulator to come to a "reasonable" solution. The same holds true if the elements provided have different characteristics.

    With the changes made to the circuit, the fixed voltage supply or battery may work fine now.