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Original question:

TPSM84824: is made using which TI IC . Can I know the part number?

TPSM84824: TPSM84824,TPSM84624,TPSM84424 :integrated inductor specification

LALIT VERMA
Expert 1695 points
Part Number: TPSM84824
Other Parts Discussed in Thread: DAC38RF80, ADC12DJ3200, TPS54824

Hi TI,

We are designing power supply for three DAC38RF80 ,which will be populated on single PCB, using TPSM84824 power module series (4A,6A and 8A modules).

We want to know the following specification of the inductor used in all three modules:

  • Inductance
  • SRF
  • Rated Current
  • Saturation Current
  • DCR
  • Inductance Test Frequency

Thanks,

Lalit

  • 0
    TI__Mastermind 19891 points

    Hello Lalit, 

    Thank you for considering this module series. 

    The inductance (0.85uH) is specified in the module block diagram on page 10 of the datasheet. 

    The inductor rated current and saturation current cover the current limit of the device. I will have to reach out to the team for the other specifications.

    I am curious to know, why do you need the SRF, DCR, and inductance test frequency specs if you are using a module? One of the reasons to use a module is to not worry about the inductor. 

    Cheers, 
    Denislav

  • 0 in reply to Denislav Petkov
    Expert 1695 points

    Hi Denislav,

    Actually as far as I know, the inductor value depends on the output current from the regulator.

    We will be using this module with three DAC38RF80 and ADC12DJ3200. Now, this DAC and ADC has several operating modes and we will be evaluating all the modes.

    All these modes have different current consumption. So current drawn  from TPSM84824 module will also vary, but the inductor value will remain same.

    Also I simulated TPS54824 on webench , IC with which  TPSM84824 series made of. And in simulation inductor value changes with output current rating of module.

    Also I have read somewhere that if we keep the inductor SRF high, then it helps in keeping the output ripple low. 

    And as we are using TPSM84824 modules with ADC12DJ3200 and DAC38RF80 (RF sampling converters) , I want to keep the ripples as low as possible so that ADC and DAC performance can be enhanced.

    So that's why to estimate the ripples, I want all these parameters of inductor.

    So it will be helpful if you can provide all the specification of inductor asked in question.

    Thanks,

    Lalit

  • 0 in reply to LALIT VERMA
    TI__Mastermind 19891 points

    Hello Lalit,

    Unfortunately I don't have SRF specification but I believe you can estimate the output ripple based on the inductance value (0.85uH). The inductor saturation rating is 12A.

    The SRF spec will only affect the high frequency (e.g. 100's of MHz) switching spikes which also depend on the input capacitor placement, PCB layout, and output capacitor value, parasitic ESL, and placement on the board.

    If you application is noise sensitive to noise, I would suggest adding placeholder footprints on your board for additional output filtering in case you have to use it (e.g. high frequency bypass caps, 2nd stage LC filter, and/or LDO).

    Cheers,
    Denislav