BQ24075: Controlling BQ24075/079 with STM32

Ahmet Talha Güleryüz

Part Number: BQ24075
Other Parts Discussed in Thread: BQ25180

I want to control BQ24075/079 battery charger with STM32L010F4P6 MCU and active low membrane keypad button. In theory what I expect is; when i press the button, SYSOFF pin to low for normal operation. When I want to close the system, I will press the button for 2 seconds which will be deteced by STM32 and it will send a HIGH state to SYSOFF pin to close the system. I create a simple diagram for this operation. Will this system work? If not can you help me to improve it? Also I am open for any suggestions. Thank you for your time and your answer.

over 1 year ago

+1 Anthony P Pham over 1 year ago

TI__Mastermind 23220 points

Hi Ahmet,

This works in theory but the issue becomes when the BQ24075/9 is powered only by battery. There's no way for us to guarantee the SYSOFF pin behavior as we do recommend not leaving it unconnected. We'd also like to ensure that the GPIO does not get damaged as the SYSOFF pin is pulled up to BAT internally.

I recommend taking a look at this application note that goes over our recommended configuration for this application: https://www.ti.com/lit/ug/sluaa18/sluaa18.pdf .

It's mentioned in the application note but there is also the BQ25180, a WCSP I2C refresh of the BQ24075 that features shipmode that also can be controlled by a button!

Best Regards,

Anthony Pham

0 Ahmet Talha Güleryüz over 1 year ago in reply to Anthony P Pham

Prodigy 50 points

Thank you Mr. Anthony, I will look into it as soon as I can.

0 Anthony P Pham over 1 year ago in reply to Ahmet Talha Güleryüz

TI__Mastermind 23220 points

Sounds good! Let me know if you have any other questions or concerns!

Best Regards,

Anthony Pham

Power management

Power management forum

BQ24075: Controlling BQ24075/079 with STM32