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TCA9548A: TCA9548A with variable I2C interface level & RESET using I2C

Jade Goo
Intellectual 1940 points
Part Number: TCA9548A

Hi Team,

TCA9548A VCC effect to master side SCL and SDA, not effect to slave channel I2C interface level, right?
For example, Master <=> 1.8V I2C <=> TCA9548 <=> (Ch. A) 2.5V, (Ch. B) 3.3V with 1.8V VCC.
Please confirm example is no issue.

Also, TCA9548A support I2C reset instead of /RESET pin control?
Thank you.

Best Regards,
Jade

  • 0
    TI__Mastermind 21575 points

    Hello Jade,

    Each channel is indepedant and requires pull ups to their respective slave Vcc voltage.    This is a pass fet architecture thus it only propagates the "LOW"s across channels and the "HIGH"s are generated via the pull up resistors on each respective channel.

    Take care in selecting Vcc.  Here is are some examples, though it is covered in datasheet.

  • 0
    TI__Guru 63000 points
    Hey Jade,

    "Also, TCA9548A support I2C reset instead of /RESET pin control?"
    -It depends why the device got stuck. Sending 9+ pulses to the SCL line can reset the state machine but it would be best to power cycle the device if possible.

    Thanks,
    -Bobby
  • 0 in reply to fhoude
    TI__Intellectual 1940 points

    Hi Fhoude,

    So no issue with VCC=1.8V and transrate 1.8V <=> 2.5V or 3.3V.
    I got it.

    Two more questions in datasheet.
    1. What is meaning of "Switch output voltage" spec? in datasheet page 5.
    2. If customer use pull-up resistor for Address pin, is there any issue? Datasheet recommend direct connection.

    Thank you.

    Best Regards,
    Jade

     

  • 0 in reply to Jade Goo
    TI__Mastermind 21575 points

    Hello Jade,

    1.  Here is how "Switch output voltage" is tested.

    2)  No issue with attaching address pins with pull up resistors.  I would suggestion 50k or so.

    -Francis Houde