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INA219: current register reading max value

Anurag Singh
Intellectual 255 points
Part Number: INA219

Hi,

I am using INA219 to measure current of a 12V rail. 

Rshunt = 0.003 ohms 

Current LSB = 381.E-6

Configuration reg = 0x0447

Current register is reading = 0xFBDF ( looks like it is reading max value eventhough current drawn is around 0.4 amps )

Please let me know what correciton i should to make to read correct values. 

Regards,

Anurag

  • 0
    TI__Expert 5640 points

    Hello Anurag,

    The formula for programming the configuration register is listed below:

    Based on this formula, the configuration value you should be using for an LSB of 381µA and an Rshunt of 3mΩ is 0x8BFB. Try this value and see if it produces the expected results. 

    Also keep in mind that the current register represents it's values in two's complement form, so the value you posted above is actually a negative reading.

    If you are still having some issues after this, if you could send the VSHUNT reading (address 0x01) as well that value is also helpful in debugging device programming issues.

    Let me know if you need more assistance,

    Levi DeVries