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BQ24250: Not using a temp sensor.

Part Number: BQ24250

Hi,

We want to use a BQ24250 in an application where the Charger/Batt Gauge are separated from the battery pack for mechanical reasons.

I do not have access to the temp sensor inside the battery pack when the battery is plugged in the charger.

The data sheet does not describe how to configure the design when not using the temp sensor.

Is there a way to use this charger without it?

If not, is there a more appropriate charger in the TI product line for this use case?

Thank you.

  • Hello Antoine, 

    Thank you for reaching out via E2E. The BQ24250 device can be used without a NTC for battery temp monitoring.  For this case the TS pin voltage needs to be maintained in the normal operation region using a resistor divider circuit. 

    I recommend you use two 20 kohm resistors in place of R2 and NTC from figure 21 on page 27 of the datasheet. That is a 20 kohm resistor from LDO to TS and a 20 kohm resistor from TS to GND. This same circuit is used to bias the TS pin on the BQ24250EVM and the schematic is shown in the EVM user guide, found on TI.com. 

    Best Regards,

    Garrett