• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 63 subscribers
  • Views 241 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

BQ25756EVM: Termination Current function not working as expected

Noel Binny Abraham
Intellectual 535 points
Part Number: BQ25756EVM
Other Parts Discussed in Thread: BQ25756

Tool/software:

Hello,

We're using the BQ25756EVM with an STM32 microcontroller to communicate with the board via I2C. Additionally, we have a digital potentiometer connected to the feedback pin, controlled by the STM32, to adjust the charging voltage.

Our goal is to charge the battery with a current of 2A and set the termination current at 1.5A. The charging process initially works without issues, but the EVM never fully terminates the charging even after the current drops below the termination threshold. When the charging current decreases to around 1A, the board begins oscillating between charging terminated and taper charging (CV) modes. During this oscillation, the Stat 1 and Stat 2 LEDs alternate, and the charging process never fully completes.

Could you help us understand why this might be happening?

Regards,
Noel 

  • +1
    TI__Mastermind 31155 points

    Hello Noel,

    Is the bit EN_PFM set to 1? When the BQ25756 has a termination current below 2A, we recommend setting EN_PFM=1. This will make the termination more accurate.

    Let me know if setting EN_PFM=1 fixes the issue. To further debug the circuit, can you send me the other registers of the BQ25756?

    Best Regards,
    Ethan Galloway