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BQ24250: BQ24250M ( Thermal protection function)

tiper liu
Prodigy 250 points
Part Number: BQ24250

Hi, All:

I am using BQ24250M in a Camera, but the environment temperature is higher, so the thermal shutdown function can be triggerd sometimes.

I have a question.

In BQ24250M  spec, there are thermal regulation [ Warm  and Hot temperature range   47degree ---60 degree ) and thermal shutdown (  die: 150 degress, the enviroment maybe is  80 degree),  So if the enviroment is between 60 -80,  what status is BQ24250?   when the charging function is disalbed, can the Vsys  be held normal status ( only turn off the power path Mosfet)?

Thanks

Tiper Liu

  • 0
    TI__Mastermind 25800 points
    Hey tiper,

    The first comment I have is this: The 47-60C range you noted is not technically thermal regulation. This is actually a feature we offer to customers who wish to monitor battery temperature using an NTC thermistor near the battery. Based on the resistor network and the thermistor the customer uses at the TS pin, the part will monitor the temperature. The NTC measurement for this part monitors the temperature and regulates charge current and battery regulation voltage based on the JEITA standard profile. The 47-60C is just what JEITA specifies as compliance.

    Thermal regulation is an internal measurement of the bq24250M's die temperature. Starting at this temperature, 125C, the charger will be begin to reduce the charge current (assuming you are not using the TS feature) until the point it hits 150C, which is thermal shutdown.

    Long story short, if your TS pin voltage goes above or below certain percentages, charging will be disabled (as a battery protection feature), but you will not lose Vsys voltage. If you hit thermal regulation at 125C, you will see a decrease in charge current until you hit 150C at which point hte part detects thermal shutdown and shuts off the part completely.


    Hope this helps,

    Regards,
    Joel H
  • 0 in reply to Joel Hernandez II
    Prodigy 250 points

    Hi, Joel:

    Thanks for your detail explanation.