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TPS61021 not available in Webench

Rick Adolf
Intellectual 335 points

I need to select the appropriate inductor and other parts for a high efficiency design. This part doesn't seem to be available in Webench. How do I get this expedited?

  • 0
    TI__Mastermind 40080 points

    Rick,

    The webbench is not available now.

    What is your input and output voltage, output current? What is your output current during the start-up? I can give the suggestion to you based on your applicaiton.

    BR,

    Helen

  • 0 in reply to Helen chen
    Intellectual 335 points
    The specs are:

    Vin: 2-3.3V
    Vout: 3V, 60-80mA
    Efficiency: as good as I can get (ideally >95%)

    I’m not sure what the start-up current will be as it depends on how much bulk capacitance there is. Do you have any rules of thumb based on other designs? This is a power and size constrained project, so I won’t be going overboard on capacitors.

    Thanks,
    Rick
  • 0 in reply to Rick Adolf
    TI__Mastermind 40080 points

    Hi Rick,

    TPS61021 is a Boost converter. It can support 2-3Vin, Vo=3V/80mA application. But when Vin > Vo, it will enter into the bypass mode, Vo=Vin, is it OK?

    BR,

    Helen

  • 0 in reply to Helen chen
    Intellectual 335 points

    YEs, that is one of the reasons i selected this part. It will be followed by an LDO set to have a Vout=2.8V. 

    Please help select the optimal inductor specs for the most efficient operation.

    Thanks,
    Rick

  • 0 in reply to Rick Adolf
    TI__Mastermind 40080 points

    What is the continuous output current, is it still 80mA? if it is then:


    The output cap can use a 22 μF/10V/X7R ceramic cap.

    The inductor has a lot of selection, here,I sugggest them to use 1uH inductor (>1A rating)in their application.

    Here's some  options: xal4020-102ME,  FDSD0420-H-1R0M  . these are 4mm*4mm inductor.

    more smaller inductor like 3mm*3mm size: XFL3010-102ME   ;2mm*2mm inductor XPL2010-102ML.


    One more question,  what is your application, could you please share it with us?
    BR,
    Helen

     

     

  • 0 in reply to Helen chen
    Intellectual 335 points
    the current range is 10-80mA with most of the time spent at 40-50mA. For highest efficiency, what DCR should I be targeting and given that size and DCR is better at lower inductance, what's the downside to reducing the inductance?

    The application is a wireless consumer product.

    Thanks,
    Rick
  • 0 in reply to Rick Adolf
    TI__Mastermind 40080 points

    As the maximum output current is small, so I'm not suggest you to use a very small inudctance inductor, because at small output current condition, the inductor loss brought from the DCR is not a key factor, the core loss maybe much higher than that of the DCR loss. And also, in most of our test, at light load, higher inductance will have higher efficiency; at heavy load, lower inductance will have higher efficiency.


    a 0.47uH-1uH inductor is suggest, but I sugggest you use 1uH inductor.


    Please click answered if you satisfied with the answer, thanks!