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TPS549B22: Bode plot analysis

Ken Kwack
Prodigy 320 points
Part Number: TPS549B22

Hello Team,

My customer request bode plot analysis of TPS549B22 with 13Vin and 0.8Vout.

1. Could I get bode plot result (GM, PM, Cross over frequency) of TPS549B22?

2. Is there any way to get Bode plot analysis by myself? I have some challanges to get bode plot from PSPICE and Webench.

Thank you! 

  • 0
    TI__Guru 51985 points

     

    pSPICE and WeBench, which uses pSPICE are not able to to generate a frequency domain Gain and Phase transfer function (Bode Plot) from a switching model, and the non-linear control loop (D-CAP3) of the TPS549B22 does not easily support an averaged pSPICE model which accurately represents its loop performance.  That is why you are not able to get a BODE plot from pSPICE or WeBench.

    I will check to see if this is something we can run for you internally, or provide you with the resources to generate.

    However, since the Vout sense to Vout loop transfer function of the TPS549B22 depends heavily on the external components, including the inductor, output capacitors, their ESRs, the feedback divider and any additional capacitive components in the loop, generating a BODE plot requires more than just VIN and VOUT, we would need the full circuit design to model.  In addition, since Switching frequency and ramp are programmed through PMBus, any programming changes made to the Fsw or Ramp would be required as well.

  • 0 in reply to Peter James Miller
    TI__Prodigy 320 points

    I totally understood, I will send SCH by email. thank you!