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BQ24450 MCU interface

Alexander Afanasjev
Prodigy 150 points
Other Parts Discussed in Thread: BQ24450

Hello guys,

I am going to implement 12V battery charger for vehicle GPS tracker based on BQ24450.

I have not found some example schematic to interface this IC to MCU like STM32.  I need to have ability to turn On/Off charging and get the charging status. I don't want to use some FET or power-path solution to turn on/off inpout voltage to the IC, but would like to use CE pin as control pin and STAT1 as status pin.

May I directly connect STAT1 pin to GPI of MCU (VDD 3,3 V)?

May I directly connect CE pin to GPIO of MCU (VDD 3,3 V) to put this pin to zero level to turn charging OFF and config pin to input-Z state to turn charging ON?

Please help me to find out proper solution.

For charging I am going to use schematic on Figure 10 page 15 of data sheet.

Thanks and Regadrs,

Alexander A.

  • 0
    TI__Genius 13700 points

    Hello Alexander,

    Looking through the datasheet the use of the CE pin to actively control whether the BQ24450 is charging can be done since it is accomplished internally with a simple voltage comparator which a switching threshold of 1V.


    The STAT1 pin will need a a pull up so that when the STAT1 is Hi-Z it will read as a high voltage and when it is low impedance it will read low. As long as you are not planning on using the boost mode the STAT1 should serve as a sufficient indicator of charging.

    You will need to make sure that you still maintain the proper resistance for the Feedback pin to ensure stability.

    Otherwise the changes that you are asking about regarding Fig. 10 should work fine.