• State TI Thinks Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 1 answer
  • Subscribers 50 subscribers
  • Views 3539 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

INA3221: Can three or four of these devices be used on the same I2C line?

Les Warshaw87
Prodigy 20 points
Part Number: INA3221

Per the datasheet, Table 1 (see below), it seems as if INA3221 can be used as four separate slave devices with pin A0 being tied to GND, VS, SDA, or SCL respectively.

Currently in our setup, we have three INA3221 ADCs:  the first INA3221 ADC has A0 tied to GND, and is working properly.  the second INA3221 ADC has A0 tied to VS, and is working properly.  The third INA3221 ADC A0 pin is tied to SCL where 1000011 is 0xF424B.  We have programmed this using the same methodology for ADCs 1 and 2, but are not getting any readings for ADC 3.  

Am I right in assuming that three or four INA3221 ADCs can be used on the same I2C line? Or is this most likely an issue in our code?

Thanks!

  • 0
    TI__Genius 15760 points
    Hi Les Warshaw87,

    Three INA3221 can be used on the same line. Your issue must be a programming or hardware issue. As you used the same programming method as other two INA's I am assuming your code is ok so lets start the troubleshooting by reviewing your schematic. Please attach your schematic to this post.
  • 0 in reply to Mayrim Verdejo
    Prodigy 20 points

    Thanks for your response! This has helped narrow down the solution a bit.  We were thinking it might be software. Attached is the schematics for the third INA3221.  As seen below, A0 is tied to SCL.  We have performed a continuity test on our PCB to confirm this as well. Any thoughts?

  • 0 in reply to Les Warshaw87
    TI__Genius 15760 points
    Hi Les Warshaw87,

    I do not see anything wrong with your schematic. I discuss your issue with my manager, he suspects it might be a timing issue. For that we would suggest you adjust the timing. Speed up or slow down the SCL and SDA. Typically, the speed is 400kHz, try 100kHz. If you are running at 1Mhz, try slower. Let me know if that fixes the problem.
  • 0 in reply to Mayrim Verdejo
    TI__Mastermind 26660 points
    Hey Les Warshaw87,

    We haven't heard from you in a while. Have you managed to establish communication with the third INA3221? I will assume you have solved your problem for now, but if you have any questions or concerns please post back to forum.

    Best regards,
    Peter Iliya
    Current Sensing Applications