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BQ76952: BQ76952 How to set the temperature threshold

Star Xu
Genius 9645 points
Part Number: BQ76952


Hi

The customer use BQ76952, they find  bq76952 will stop work at 75˚ C, how to set the over temperature protection to 85˚ C?

They try to set the SHUTDOWN TEMPERATURE 0x9244U,  BQ769x2_SetRegister(SHUTDOWNTEMPERATURE, 120, 1U); will went to  protection at 85˚ C.

How to set the over temperature protection threshold?

Waiting for your reply.

Thanks

Star

  • +1
    TI__Mastermind 27321 points

    Hello Star,

    The BQ76952 has several over temperature protections. Please see below



    Which OVT protection is customer trying to use?

    As for the Shutdown Temperature, the device will enter shutdown mode if (Internal Temperature > Power:Shutdown:Shutdown Temperature) for Power:Shutdown:Shutdown Temperature Delay seconds. By default the is  Power:Shutdown:Shutdown Temperature 85˚ C. Maybe the threshold did not get properly changed. I suggest reading back from address 0x9244 to see if it is set to 120˚ C.

    Maybe also set the Internal Overtemperature Protection in Protections:OTINT:Threshold to 120˚ C or disable the Settings:Protection:Enabled Protections B:[OTINT] configuration bit.

    Regards,
    Jose Couso

  • 0 in reply to Jose Couso
    TI__Genius 9645 points

    Hi Jose

    Thanks for your help.

    The register set as below.

    BQ769x2_SetRegister(SHUTDOWNTEMPERATURE,120,1);
    BQ769x2_SetRegister(OTINTTHRESHOLD,115,1);
    BQ769x2_SetRegister(OTINTRECOVERY,113,1);
    BQ769x2_SetRegister(SOTTHRESHOLD,113,1);
    BQ769x2_SetRegister(SOTFTHRESHOLD,113,1);

    It does work, but when the temperature reaches around 85°C, the measured AFE will enter SHUTDOWN and needs to be woken up.

    After waking up, the AFE can continue to work at the high temperatures(temperature is higher than 85 degrees) and it will not SHUTDOWN.

    May I ask what is the reason for this? where else needs to be set?

    Waiting for your reply.

    Thanks

    Star

  • 0 in reply to Star Xu
    TI__Mastermind 27321 points

    Hello Star,

    We recommend to operate the BQ76952 in between -40C and 85C for max conditions. An external thermistor can be used to measure the voltage on the cells, but max operating temp for internal purpose is 85C.



    Why is the customer going so high on temperatures? Can you explain the use case?

    Regards,
    Jose Couso