• State TI Thinks Resolved
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 33 subscribers
  • Views 66 views
  • Users 0 members are here
Support feedback
Options
Options
Related

TCA9517: Open-drain I/O(SDAA,SCLA,SDAB and SCLB) - Implementation

MithunKumar V
Prodigy 10 points
Part Number: TCA9517

Tool/software:

Hi,

Based on the following characteristics(as provided in datasheet),

"Open-Drain I2C I/O"

"High-Impedance I2C Pins When Powered-Off"

We consider that below operating conditions does not allow any backdrive/current leakage from pull-ups on SDAB and SCLB to VCCB.

TCA9517 with VCCA and VCCB =0V(Unpowered) and pull-up at B side provided with different active voltage source (Amplitude of voltage=VCCB).

In above mentioned condition, it is expected that SDAB and SCLB remains at high impedance without any backdrive to VCCB (Assumption: open-drain SDAB and SCLB has no internal pull-ups).

Query:

Kindly confirm that there are no internal pull-ups for SDAA, SCLA, SDAB and SCLB.

Also suggest if there are any abnormalities expected in the above mentioned operating condition.

Regards,

MithunKumar V

  • 0
    TI__Mastermind 47128 points

    Hi MithunKumar,

    MithunKumar V said:

    TCA9517 with VCCA and VCCB =0V(Unpowered) and pull-up at B side provided with different active voltage source (Amplitude of voltage=VCCB).

    In above mentioned condition, it is expected that SDAB and SCLB remains at high impedance without any backdrive to VCCB (Assumption: open-drain SDAB and SCLB has no internal pull-ups).

    You are correct. 

    MithunKumar V said:
    Kindly confirm that there are no internal pull-ups for SDAA, SCLA, SDAB and SCLB.

    No internal PU resistors on these lines, these need to be provided externally by the user. 

    No ESD diode from SDA/SCL to VCCA or VCCB that could be a path for back-powering the supply. 

    Regards,

    Tyler