• State TI Thinks Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 441 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.

BQ24715: bq24715 could not loading above 1.5A on 1MHZ frequence

user4380996
Prodigy 105 points
Part Number: BQ24715

HI,

We use 2S battery project,when we test the AC Mode without battery ,the OS will shutdown.

if adjust the frequence to 600KHZ or 800KHZ, the os will normal,

after change to 1MHZ, the issue will duplicate easyly.

 

second, we use the electric load load 5A ,the 600KHZ is ok, 1MHZ is fail.

1MHZ setting only support 1.5A load only.

third, the schematic is the MP schematic without this issue.

could you please help why 1MHZ could not loading above 1.5A .

  • 0
    TI__Genius 11850 points

    Hi,

    I tried this on an EVM and don't have any issues pulling 5 A from SYS with a 1 MHz switching frequency, as shown in the waveform below. My adapter voltage is 20 V, and I have the EVM configured for 2-cell charging. I did not have a battery connected, and I was using an e-load in constant current mode to pull current from SYS.

    Can you describe your test setup? Do you only have the adapter and the e-load connected? What is your adapter's voltage and current capability, and can you send me your register values so I can try to duplicate your setup as closely as possible?

    Best regards,

    Angelo

  • 0 in reply to Angelo Zhang87
    Prodigy 105 points

    Angelo,

    Thanks!

    Test Setup,1 plug in adapter(19V/3.5A) in M/B.2.Test Vsys voltage is 8.8V.   3. Load 5A use electric loading.  4.the Vsys drop to 2V. 5.test the ACDRV Pin the voltage will drop to zero then clamp up to 25V. 6    close the electrc load, vsys voltage come back to 8.8v again. by the way, tune the loading, charge can only support 1.5A loading. any other bigger than this value,vsys will drop to 2V.

    Regesister only set 

    0X12=665E other regesister as default value.

    after write 0X12 to E144,the vsys will OK can load 5A.

  • 0 in reply to user4380996
    TI__Genius 11850 points

    Hi,

    I tried to follow your test procedure, but was unable to duplicate the issue. I still have no problem pulling >1.5 A from SYS with a 1 MHz switching frequency.

    Can you capture some waveforms to show PHASE, VSYS, and ISYS for both 800 kHz and 1 MHz switching frequencies? Also, do you have a BQ24715 EVM that you can test this with?

    Best regards,

    Angelo

  • 0 in reply to Angelo Zhang87
    TI__Genius 11850 points

    Hi,

    We haven't heard back from you. We are assuming you were able to resolve your issue. If not, just post a reply below or create a new thread if the thread has locked due to time-out.

    Best regards,

    Angelo