About ADP2389 Accuracy and minus current

Hi, 

I would like to use ADP2389.

So, I have two questions.

#1  When RILIM = 59 kΩ, the peak current is stated as 15 ~ 18.6 A. (From data sheet)
    Is this variation in output peak current equivalent (about ± 10.7%) even if the resistance value is changed?
       Are there any indicators?

#2   Is there any problem if a negative current flows in the FET of ADP 2389?

Best Regards,

Yuya

  • Hi Yuya,

    The RILIM sets the peak current limit threshold of the inductor peak current and not of the output peak current.  You'll get about ± 10.7% variation if the resistor value is close to 59kΩ. May I know what RILIM are you planning to use so that we could check if how much will the variation be?

    There won't be any problem if negative current flows in the FET as long as it is less than 4A.

    Best Regards,

    Alex

  • Hi, Alex

    Thank you for your answer.

    I understand setting the inductor current peak current limit threshold.
    If it is close to 59 kΩ, it is about ± 10.7% fluctuation, but as long as the value of resistance goes away from 59 kΩ it is said that unless I experiment, I do not know the degree of variation?
    Currently, I specifically have no plans to check variations.

    I realized that if the negative current is up to 4 A, it does not matter if it flows in.

    Best Regards,

    Yuya

  • Hi Yuya,

    You can compute for the typical value, but yes for the maximum and minimum limit, you cannot determine the variation unless you experiment. What we usually do to determine the max and min limit is by full characterization.

    Best Regards,
    Alex

  • Hi, Alex

    I'm sorry for the reply late.
    thank you for your answer.
    I acknowledged it.

    Best Regards,

    Yuya