• State
  • Locked Locked
  • Replies 3 replies
  • Subscribers 47 subscribers
  • Views 160 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.

INA226EVM: I2C Communication Issue with INA226 on S32K31EVB Board

santhosh kumar
Prodigy 20 points
Part Number: INA226EVM
Other Parts Discussed in Thread: INA226

Tool/software:

Ticket Title: INA226 EVK Board - Incorrect Current Measurement After Power Cycling

Description:

We are using the INA226 EVM board for current measurement. We encountered the following issue:

  1. When the board is powered on and a current of 10A is applied to the shunt resistor, the measurement is correct and shows approximately 10A.

  2. However, when we frequently turn the power off and on, the current measurement becomes struck at one value. Specifically:

    • The shunt resistor value becomes stuck at 4096.

    • The current measurement displays 62A.

This behavior occurs intermittently after multiple power cycles.

Request:

We would like assistance in understanding and resolving this issue:

  • Is this behavior related to the INA226 configuration or initialization process during power cycling?

  • Are there specific registers or settings we need to check or adjust?

  • Could this be a hardware or firmware limitation of the INA226 EVM?

Environment:

  • INA226 EVM board

  • Current applied: 10A

  • Observed incorrect measurement: 62A after power 

Please provide guidance on how to address this issue.

  • 0
    TI__Mastermind 26525 points

    Hello Santhosh,

    I have a few questions to help debug this:

    1. Are you using default settings on the INA226, or are you programming them with each power up?

    2. Are you getting the current value from the shunt voltage register or the current register?

    3. When powering down, does the supply go all the way to 0V?

    4. Could you send me a readout of all register values at the time of the unexpected measurement? Please also let me know your shunt resistor size and the maximum expected current you used to calculate your Calibration register value.

    Regards,

    Mitch

  • 0 in reply to Mitch M
    Prodigy 20 points

    Hello Mitch M,

    1. No, we have configured the configuration register with the value 0x4427.
    2. We are obtaining the current value from the current register only.
    3. Yes, during power-down, the supply goes completely low to 0V.
    4. We are using a 50 micro-ohm shunt resistor. The maximum current is 500A. The current register value is 4096, and with one LSB equivalent to 15mA, the actual current calculation is as follows

               Actual Current=15mA×Current Register Value=62A. 

    Kindly support to resolve these issues.

    Thanks,

    Santhosh

  • 0 in reply to santhosh kumar
    TI__Mastermind 26525 points

    Hello Santhosh,

    Can you confirm the value you are programming to the CALIBRATION register? Also, during the time of the unusual read, can you confirm the voltage measurement across the IN+ and IN- pins of the device (right at the pins, not at the shunt), and also give me the value in the shunt voltage register?

    Regards,

    Mitch