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BQ24715: What conditions will make BQ24715 to discharge the battery to supplement system power?

Part Number: BQ24715

Tool/software:

dears,

according to the datasheet of BQ24715 "If system power demand is temporarily exceeds adapter rating, the bq24715 supports NVDC architecture to allow battery discharge energy to supplement system power",  but there is no  description about the detailed condition that lead BQ24715 to start supplement discharge mode. would you please help to clarify this? does it requires the system voltage to drop below the MinSystemVoltage that we set?

by the way, how fast will BQ24715 response to enter into supplement discharge mode?

thanks!

  • dears,

    as well, in the case that the adapter is being inserted, but the system load increases to be higher than the adapter current capacity (or the input current limit) ,the system voltage should start to drop, upon the system voltage dropped to be lower than the battery voltage -FET forward voltage of the body diode, the battery should be able to supply power to the system via the body diode of the FET,  even though the BATDRV still not turn on the FET in time,  am i right?  what is the condition that makes BQ24715 to turn on the discharging FET? how fast may it response?

    thanks a lot!

  • Hello Andrew,

    does it requires the system voltage to drop below the MinSystemVoltage that we set?

    Yes, This is correct, the system voltage has to drop below the MIn_SyS value to enter supplement mode. 

    how fast may it response?

    We don't have the data to provide an accurate answer.

    Best Regards,

    Christian

  • Dear Christian,

    thanks a lot for the confirmation. 

    please also help to share me the detailed condition that makes BQ24715 to turn on the discharging FET in suplement mode and when turn to discharging mode.

    thanks!

  • Hello Andrew,

    The BQ24715 is a legacy device so I can only go off the limited information that we have. The bq24715 features Dynamic Power Management (DPM) to limit the input power and avoid AC adapter overloading. During battery charging, as the system power increases, the charging current will reduce to maintain total input current below adapter rating. If system power demand is temporarily exceeds adapter rating, the bq24715 supports NVDC architecture to allow battery discharge energy to supplement system power. We do not have the data to provide an estimate on when the device turns on supplement mod.

    Best Regards,

    Christian

  • dear Christian,

    ok. thank you!