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TPS25221: Regarding the inrush current limiting

Kyohei
Expert 1440 points
Part Number: TPS25221

Tool/software:

Hi team,

Is it possible to limit the inrush current to below 500mA with this device?

The USB Power-Distribution Requirements in section 10.2.3.1.1 state "Limit inrush current (<44 Ω and 10 µF)." Does this mean that if Rilim is less than 44Ω, it can handle the inrush current?

Additionally, are there similar devices with better (newer) supply availability? Regarding the TPS25221, is it a product that can be used long-term without any supply issues?

Best regards,

Kyohei

  • 0
    TI__Mastermind 46311 points

    Hello Kyohei,

    Yes, but if the load is more than the parallel combination of 44ohm and 10uF at power, then inrush current limiting must be implemented.

    The TPS25221 is the latest for adjustable 2A max power switches, so risk of supply issues are very low.

    Thank you and best regards,

    Seong

  • 0 in reply to Seong Kim
    Expert 1440 points

    Hi Seong,

    Thank you for your support.

    It is necessary to limit the inrush current when the load exceeds 44 Ω and 10 µF.

    Could you please provide specific methods to limit the inrush current to within 500mA?

    Best regards,

    Kyohei

  • 0 in reply to Kyohei
    TI__Mastermind 46311 points

    Hello Kyohei,

    TI recommends placing a high-value electrolytic capacitor on the output pin when large transient currents are expected on the output.

    Thank you and best regards,

    Seong

  • 0 in reply to Seong Kim
    Expert 1440 points

    Hi Seong,

    Thank you for your support.

    I understand that a high-value electrolytic capacitor will be placed on the output pin.

    Is this to be connected as an output capacitor?

    Also, is there a method for calculating the capacitance value of the electrolytic capacitor? If so, please let me know.

    Best regards,

    Kyohei

  • +1 in reply to Kyohei
    TI__Mastermind 46311 points

    Hello Kyohei,

    It depends on the specific application condition. The part does have the soft start function, so it can reduce the inrush current.

    Has the customer tried testing this on an EVM with the ILIMIT configured to 500mA? If not, please advise the customer to try testing this first with the inrush current scenario they are anticipating.

    BR,

    Seong