• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 47 subscribers
  • Views 669 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.

INA231: About Address Pins and Slave Addresses

Tsukui Yusuke
Guru 21930 points
Part Number: INA231

Hi

Could you tell me about slave addresses setting?

１. What is the recommended pull-up resistor when connecting to SDA or SCL?
２. Please tell me the difference between connecting to SDA or SCL and connecting to Vs.
　  If I2C is pulled up with the same voltage as VS,
     What is the difference between addresses?



Regards,
Yusuke

  • 0
    TI__Mastermind 22560 points

    Yusuke,

    1. Are you asking for a pull-up resistor recommendation between Vs and the I2C lines, or are you asking for the purposes of addressing? For addressing, no pull-up is needed, you simply connect A0 or A1 to the appropriate node. For the purposes of pulling up to the supply, we utilize 10k resistors on the INA231EVM. That said, pull-up resistors are often system specific, and the customer may need to tweak this value based on the totality of their system. The trade-offs of this is discussed in depth in this app note. 

    2. The device has the ability to ascertain which node it is connected to, as explained in section 8.5.5.1.1 of the datasheet. The device compares the inputs of A0 and A1 with Vs, GND, SDA, and SCL to see if they are shorted together, and then sets the I2C address internally based on the results of that comparison. 

  • 0 in reply to Carolus Andrews
    Guru 21930 points

    Hi Andrews,

    Thank you for your kind support.

    Could tell me more about the answer in 2.

    When SDA or SCL is pulled up with Vs,
    How does the device tell the difference?




    Regards,
    Yusuke

  • 0 in reply to Tsukui Yusuke
    TI__Mastermind 22560 points

    Yusuke,

    The device detects shorts between the pins. The level of voltage does not matter.