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BQ25708: Replace BQ25700AEVM with BQ25708

Part Number: BQ25708
Other Parts Discussed in Thread: BQ25700A, , BQ25756

Hi,

A related question recommends replacing BQ25700A with BQ25708. When replacing the BQ25708, the pin arrangement is the same except for the 5 pin of the NC, so will it be possible to operate by simply replacing the board without revising the board? Also, the data sheet says BAT temp thermistor monitoring, but could you tell me which terminal can be used for monitoring?

The functions required of a charging IC are as follows.
・Battery temperature monitoring possible
・Temperature management of charging IC
・Charging voltage: 8.25V
・Battery to be charged: Lithium ion battery (2cell)

As a background for the above question, we are considering evaluating the BQ25708 on EVM, but if there is a charging IC other than the BQ25708 that is suitable for the conditions, I would like to know.

Thanks,

Conor

  • Hi Conor,

    I am not clear what you mean by 'simply replacing the board without revising the board'. Can you clarify?

    Also, I could not find the word thermistor in the datasheet for both BQ25708 and BQ25700A. These charge controller does not have battery temperature sensor pin. Can you clarify which datasheet you found BAT temp thermistor monitoring? 

    The BQ25756 can be an option if you require battery temperature monitoring with TS pin. You can also charge the battery with JEITA temperature guidelines.

    Best Regards,

    Munir

  • Hi Munir,

    I am not clear what you mean by 'simply replacing the board without revising the board'. Can you clarify?

    I would like to know if it is possible to evaluate on EVM just by replacing the IC.
    I don't think there is any need to change the circuit on the EVM since pin assignment except pin 5 is the same.

    This is the yellow marker below. The data sheet does not mention "BAT temp thermistor monitoring", so is it a mistake?

    Thanks,

    Conor

  • Hi Conor,

    Thanks for the clarification. Yes you can replace the IC on the EVM.

    The screenshot you presented is from BQ25756 that I suggested. Your original question is about BQ25708 and BQ25700A. None of the devices have any BAT temp thermistor monitoring and do not mention it in the datasheet. 

    Were you referring to the BQ25756 datasheet in your original question?

    Best Regards,

    Munir

  • Hi Munir,

    Sorry, I attached the wrong image.
    The product page for BQ25708 says "BAT temp thermistor monitoring," but the data sheet does not. Is this a typo on the product page?

    Thanks,

    Conor

  • Hi Conor,

    Thanks for pointing it out. This is a typo. We will fix it as soon as possible.

    Best Regards,

    Munir