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TPS65917EVM: Question about I2C communication

Part Number: TPS65917EVM

Hello teams,

If I would like to do I2C communication for SMPS,

should I connect J35 for SCL and J36 for SDA with pull up resistor?

If so, is pull up resistor compulsory?

Thank you.

Sincerely,

  • Hello Jinwook,

    If you want to use an external microcontroller to do I2C communication, I suggest you use J7 and J10, these are directly connected to the PMIC. However, these are connected to J35 and J36, so you can use those J35/J36 as long as you have J7 and J10 installed.

    I2C is an open-drain interface, so you always need a pull-up resistor. You can either use the on-board pull-ups, or there may be pull-ups on the microntroller board that you are using.


    Regards,
    Karl
  • Hello Karl,

    One last question.

    I am trying to use J35 and J 36 but they are with default jumper setting.
    I am curious whether it will be okay to make changes to it. ( taking the jumper off and connect the SDA, SCL, and ground to the J35 and J36 pin)

    Thank you.

    Sincerely,
  • Hi Jinwook,

    Yes, that is ok to remove J35 and J36 jumpers. I'm assuming you are using an external microcontroller. In that case, connect the SDA and SCL pins to J35 and J36 pin 2. Just make sure that J7 and J10 are installed so that the external microcontroller is connected to the PMIC.

    Regards,
    Karl
  • Hello karl,

    Instead of j35 and j36, I am thinking about connecting my microcontroller directly to J7 and  J10.

    However, what do you mean by pin2?

    I see that there are 2 pins at both J7 and J10.

    Do I have to consider which pin is for SDA and which pin is for Ground within J7?

    Thank you.

    Sincerely

  • Hi Jinwook,

    J7 and J10 will work too. You should connect your microcontroller to pin 2 of these headers.

    On the schematic, each header has pin labels so you can tell which pin on the board represents each pin the schematic. J7 has two pins labeled 1 and 2. On the silkscreen on the EVM, there is a "1" label next to pin 1. I just mean that you should connect it to the other pin, since J7 pin 2 is the direct connection to the PMIC I2C pins.

    Regards,
    Karl