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TPS61088: About variation of current limit value

Tsukui Yusuke
Guru 21930 points
Part Number: TPS61088

Hi,

Could you tell me about variation of current limit value?
The data sheet describes the current limit variation information of the specific condition.





However, customers want variation information other than 100kΩ.
Please tell me how to estimate the current value MIN and MAX obtained by the following calculation.



Regards,
Yusuke

  • 0
    TI__Mastermind 40080 points

    Dear Sir,

    Under PFM mode, they can calculate the current according to the formula:

    Ilim=1190000/Rlim, when R=119000 ohm, then Ilim=10A typ, and 8.7A minimal;

    Under the PWM mode,they can calculate the current according to the formula:

    Ilim=1190000/Rlim -1.6A, when R=119000 ohm, then Ilim=10A-1.6A=8.4A, and 7.1A minimal;

  • 0 in reply to Helen chen
    Guru 21930 points

    Hi Helen,

    Thank you for your support.
    Does the calculation method correspond to various Ilim values?

    For example,

    Under PFM mode,
    Ilim=1190000/Rlim, when R=xxx ohm, then Ilim=yA typ, and y-1.3A = minimal;

    Under the PWM mode,
    Ilim=1190000/Rlim -1.6A, when R=xxx ohm, then Ilim=yA-1.6A= and y-1.6A-1.3A minimal;

    Is this understanding right?
    Customers want to know what percentage of the following calculation results vary.
    □ ILIM=119000/RILIM=xxxA±xx％

    Also, are there maximum and minimum values for 1190000?


    Regards,
    Yusuke

  • 0 in reply to Tsukui Yusuke
    TI__Mastermind 40080 points

    Dear Yusuke-San,

    Yes, your understanding is right. It is

    Under PFM mode,
    Ilim=1190000/Rlim, when R=xxx ohm, then Ilim=yA typ, and y-1.3A = minimal;

    Under the PWM mode,
    Ilim=1190000/Rlim -1.6A, when R=xxx ohm, then Ilim=yA-1.6A= and y-1.6A-1.3A minimal;

    For the maximum value, it is

    Under PFM mode,
    Ilim=1190000/Rlim+1.1A maximum

    Under the PWM mode,
    Ilim=1190000/Rlim -1.6A+1.1A maximum

  • 0 in reply to Helen chen
    Guru 21930 points

    Hi Helen-san,

    Thank you for your kind support.

    How should "Ilim min max" be considered for settings smaller than 2.9A or 1.6A?



    Best Regards,
    Yusuke

  • 0 in reply to Tsukui Yusuke
    TI__Mastermind 40080 points

    Dear Yusuke-San,

    If we set the typ. current limit at 2.9A, then the real output current will be very low(near 0A) under PWM mode.