• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 261 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.

BQ2026: BQ2026 IC for battery authentication

Shashi Rai
Prodigy 120 points
Part Number: BQ2026
Other Parts Discussed in Thread: EV2400

Tool/software:

I am currently working on a project where I have implemented the BQ2026 IC for battery authentication. However, I am encountering issues when trying to read the unique ID of the BQ2026. Below are some specific concerns:

  1. Pull-up/Supply Voltage:
    Could you please confirm whether the correct pull-up or supply voltage for the BQ2026 should be 3.3V or 5V?
    (At present, we have connected it to 3.3V.)

           

 

  1. SDQ Line Voltage and Pull-up Resistor Value:
    What is the expected initial or ideal state of the SDQ line? When using a 10kΩ pull-up resistor, we measured a voltage of 0.5V on the SDQ line (at the GPIO pin of the controller). However, when the pull-up resistor value was reduced to 1kΩ, the voltage increased to 3.23V. Could you confirm the appropriate pull-up resistor value for the SDQ line?
  2. Reading the Authentication IC:
    While attempting to read the default value of the authentication IC, I am consistently receiving "0000000". For reading the value, I am using an ESP-WROOM-32 module. I have attached an image for reference.
    (Note: We are using the ESP-WROOM-32 just for proof of concept at this stage.)

            

  1. Capture the signal wave foam ESP-WROOM-32 of GPIO - D4.

       

             

 

 

 

  1. According to the EVM reference manual, programming the BQ2026 requires an additional 12V circuit along with the EV2300. However, I currently have the EV2400 module. Could you suggest an alternative method to write/program data to the BQ2026 using an ESP-WROOM-32 or any other microcontroller?

 

           Thanks & Regards,

           Shashi Kumar Rai

  • 0
    TI__Mastermind 49956 points

    Hello Shashi,

    1. VPUP can be from 2.65V to 5.5V. So 3.3V shouldn't be a problem.

    2. As indicated in the datasheet, Rpup is 5K ohm

    3. How does the device respond when you issue a reset pulse for tRST duration?

    4. Can you show the waveform for the reset pulse?

    5. BQ2026EVM is not supported by EV2400. In your microcontroller, you can use a GPIO to provide a programming pulse on the PROG pin (J1 - pin 2) in the EVM  

  • 0 in reply to Praveen Aroul
    Prodigy 120 points

    Hello Praveen Aroul,

    Thank you for your prompt response and suggestions.

    I have updated the Rpup to 5K ohms, and after removing the C6 capacitor, the SDQ line voltage has now increased to approximately 3.2V from the previous 0.5V. We are now able to successfully read the device ID. It seems that the C6 capacitor may have been causing the issue in the design.

    Thanks and regards,
    Shashi Rai

  • +1 in reply to Shashi Rai
    TI__Mastermind 49956 points

    Hello Shashi,

    Thanks for the update. For some reason, the schematics did not show up earlier in my view of the e2e post and I didnt notice the capacitance on the SDQ pin.

    Yes, any capacitive load would violate the device timing spec and as you figured out, that was the cause of the issue in your design.

    Let me know if you have any further questions.