• State TI Thinks Resolved
  • Locked Locked
  • Replies 2 replies
  • Answers 1 answer
  • Subscribers 47 subscribers
  • Views 324 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.

XTR115: Short IRET and supply ground temporary

Van-Ngoc Nong
Prodigy 150 points
Part Number: XTR115


Hi,

is it possible to short IRET and Io (supply ground) temporary? Would the XTR be broken?

Background is, the XTR supplies a MCU and in production I want to communicate with the MCU over UART (USB to Serial FTDI).

Between IRET and Io is a 25Ohm resistor, in the worst case a potential of ~0.5 V is present. I'm afraid it is not good for the MCU.

Best regards

Ngoc

  • 0
    TI__Guru 55466 points

    HI Van-Ngoc,

    You may get a transient of current flowing through the external BJT transistor into the device, the XTR115 can only withstand 32mA current continuous.

    Edit: 7-6-23: Although the device has an internal current limit function to limit the loop current to 32mA, I am not certain that the current limit will work properly when shorting Io and IRET. 

    Shorting IRET and IO will likely create a current transient on the circuit. The loop current flows through internal resistors; therefore, damage is possible with excessive current, or currents greater than 45 mA can cause permanent damage.

    Do you have an schematic?  What is the loop voltage supply, and is there an external loop supply current limit?

    Thank you and Regards,

    Luis

  • 0 in reply to Luis Chioye
    TI__Guru 55466 points

    HI Van-Ngoc,

    I have not heard back.  I assume the issue was resolved, however, please let us know if you still require assistance.

    Thank you,

    Kind Regards,

    Luis