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Original question:

CSD95490Q5MC: Equivalent Series Resistance/Inductance

CSD95490Q5MC: Series R/L model

GRACE HU
Prodigy 30 points
Part Number: CSD95490Q5MC

Hi,

I'm trying to simulate the PDN impedance with a TI buck CSD95490Q5MC.   The load is an Altera/Intel FPGA and they have provided a calculator for the Power Distribution Network (PDN).    In order to calculate the source impedance of the VRM, we need to provide an ideal model with equivalent resistance and inductance. Could you please help me with this? I saw similar post on this question, but did not see the answers.

Thanks!

Grace

  • 0
    TI__Intellectual 800 points

    Dear Grace,

    The drawing you attached above is not related in any way with CSD95490Q5MC device.

    Let me help you with the model :

    -you show in your model 4 Decoupling Caps, each one of them includes parasitic RLC. Please consult with your specific Cap vendor.It all depends what type of Caps you're using, package, value , dielectric material etc

    -you also show in your model Planar Rp and Cp and Spreading R and L. Those are PCB related and depend on your Layout, number of Layers, stacking etc

    These are not parts made by TI and if you want specific information on Caps, PCB and their parasitic models, please inquire with your vendors.

    Best Regards.

  • 0 in reply to Lucian Hriscu
    Prodigy 30 points
    Lucian,

    If you look at the red circle in the drawing, it is the R/L model of the VRM (TI CSD9549). This is a similar question as one posted on this forum before, and I think someone from TI already solved it. I could not find the answers on the forum, so repeated the same question.

    Thanks,
    Grace
  • 0 in reply to GRACE HU
    TI__Intellectual 800 points

    Grace,

    The red circle in the drawing points out to the VR output stage impedance, not the CSD95490 device itself. The previous post was locked, that's why you can't find the answer here.Please take it offline and contact Brett Barr for more detailed information.

    Best regards,

    Lucian