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BQ24172: TS operation when there is no battery

PAN-M
Mastermind 8375 points
Part Number: BQ24172

Hi,

bq24172 does not work if it does not have a battery.
TS exceeded a range when I checked it. (RT1=12k, RT2=68k)
VLTF=2.426V, If no battery, TS=2.805V
(RT1 = 5.23 kΩ RT2 = 30.1 kΩ from datasheet, TS=2.811V)
Both case become out of a range.

Do you have the method to operate without a battery?

Best Regards,
PAN-M

  • 0
    TI__Mastermind 40305 points

    Dear PAN-M,

    Without a thermistor, the given resistor values produce a voltage of 2.805 V and 2.811 V on TS. These values are 85% and 85.2% of VREF and are well beyond the VLTF threshold of 73.5% of VREF to suspend charge for a cold temperature event.

    If you do not wish to use a thermistor, the voltage divider needs to be biased to permanently put the part in a valid TS range. If you wish to use a thermistor, you need to program the temperature threshold as shown in Section 9.3.18 of the datasheet.

    Thanks,

    Mike Emanuel

    Please click "This resolved my issue" button if this post answers your question.