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LM5176-Q1: Is there a way to charge 3A CC-mode? -LM5176-Q1

BAKE KI
Prodigy 80 points
Part Number: LM5176-Q1
Other Parts Discussed in Thread: LM5176, BQ24616

I will design a battery charging circuit with the LM5176.

I want to charge 3A CC-mode, is it possible?

If Hiccup or Average Current Limit is off, the current will flow over 3A without limitation.
And if I turn on the two functions, I think that the current will rise and the charging will end at 3A.
In general, the battery will be charged by CC-CV, so the cut-off time will be very short.

I cannot use Chager IC because I have to use AEC-Q100 certified product.
As far as I know, BQ24616 etc. do not have AEC-Q100.

Is there a way to charge 3A CC-mode?

Vin: 10 ~ 16V, Vout: 14.6V / 3A, and there is an immutable fuse in the Vin line, so you must limit the current.

  • 0
    TI__Mastermind 21720 points

    Hi BAKE KI,

    Thank you for reaching out with your question and for considering the LM5176 in your design.

    The LM5176 can be configured to output a constant current using the average current limiting feature. Placing a resistor between the ISNS+ and ISNS- pin will limit the current when the voltage drop across the resistor is 50mV.

    Please let me know if you have any other questions.

    Thanks,

    Garrett

  • 0 in reply to Garrett Roecker
    Prodigy 80 points

    Thank you so much for answering.

    The battery capacity is 7.2 Ah.
    What resistance should I use for 3A CC charging?

    If you use 0.015 ohm for the sensing resistance between ISNS + and ISNS -...
    Is 45mV when charging at 3A, and 51mV at 3.4A to cut off the current?

    If it is correct ... I think that as soon as the charging starts, the current will flow more than 3.4A, and the charging will end within a few seconds.

  • 0 in reply to BAKE KI
    TI__Mastermind 21720 points

    Hi BAKE KI,

    It is possible to add multiple resistors in parallel to set a static current limit for the average output current. 17mOhm will set the typical output current to 3A

    Please let me know if you have any questions.

    Thanks,

    Garrett

  • 0 in reply to Garrett Roecker
    Prodigy 80 points

    3.3A CC-Mode operation was confirmed by applying a 15mΩ resistor.
    All thanks to you.

    Can the input current be maintained at 3A by changing the 15mΩ resistor position to Input?

  • 0 in reply to BAKE KI
    TI__Mastermind 21720 points

    BAKE KI,

    Yes moving the resistor to the input voltage rail will be used to limit the input current.

    Thanks,

    Garrett