• State TI Thinks Resolved
  • Locked Locked
  • Replies 5 replies
  • Answers 2 answers
  • Subscribers 63 subscribers
  • Views 309 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

BQ25890: output current limit

liping pan
Intellectual 650 points
Part Number: BQ25890

Hello,

In the below link topic, you mentioned the max current limit is about 9A/100us.

But I found it documented 1s in your datasheet. Can you clarify which one is the right value?

BQ25890: why sys voltage drops - Power management forum - Power management - TI E2E support forums

  • 0
    TI__Mastermind 31100 points

    Hi Liping, 

    The 1 sec timing mentioned in the datasheet is the maximum recommended amount of time for discharge current through BATFET to be above 6A. The 100 usec timing mentioned in the alternate thread you linked refers to the deglitch time for the overcurrent protection to trigger and turn off the BATFET. 

    The recommended operating conditions section of the datasheet states Ibat discharge current can be up to 6A continuously. TI then recommends if Ibat discharge current rises to between 6A and 9A to not draw said current for more than 1 sec duration. If current draw rises above recommended max of 9A there is 100 usec deglitch time for the overcurrent limit protection. 

    Best Regards,

    Garrett 

  • 0 in reply to Garrett Kreger
    Intellectual 650 points

    Hi,

    How do you judge below picture? It's an issue or not.

    It's caused by big capacitor during power up.

    5A/Div.

  • 0 in reply to liping pan
    TI__Mastermind 31100 points

    Hi Liping, 

    Where is the current being measured? Is it the battery discharge current from BAT to SYS after battery is plugged in? Also can you share what the time/div in the waveform is as well? It is hard to tell from image. 

    Best Regards,

    Garrett 

  • 0 in reply to Garrett Kreger
    Intellectual 650 points

    It's from BAT to SYS (no power adapter connected).

    Timebase: 2.5ms/div

  • 0 in reply to liping pan
    TI__Mastermind 31100 points

    Hi Liping, 

    Based on our recommended operating conditions ideally you want to reduce the magnitude of the current spike below the recommended maximum discharge current of 9A. 

    In reality since the BATFET_OCP protection is not turning off the BATFET as a result of this behavior at power up from battery it should not be an issue. 

    Regards,

    Garrett