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XTR111: In my new project, i need to generate a current loop from main control board. I am using xtr111 for this purpose. Can anybody verify the circuit for 4-20mA Current loop. We have issues on error flag, Error flag is always set.

Part Number: XTR111

  • Hi Karthikeyan,

    I don't see anything immediately wrong with your schematic. What are the conditions under which you observe this behavior? What is the input signal? Do you have the load connected? If there is no path for current to flow then the error flag will be active.
  • Hai Kaye,
    Thank you very much for your quick response, The input signals are 3.3V & 5V, We does not received any voltage across the load.
    yeah we have connect the external load resistance of 220 OHM.
  • I see that you have two different grounds in your system. Can you verify that the ground your load is connected to and the ground the input is referenced to are the same as the XTR supply ground?
  • Hi Kaye,
    Yeah, We are verified the ground connection across our load as well as input signal.
  • Hi Karthikeyan,

    Unfortunately from what you have shared there is not enough information to ascertain what the root of the issue is. If you could please share your input circuitry and output connections then this may shed some light on the issue.

    Have you tried swapping the part on the board to see if the behavior persists?
  • Hi Kaye,

             I have attached the over all schematic diagram for current loop, We have to use the two different GND singal, Kindly refer the schematic 

            We have to verified that the load ground is connected to the input ground and also refereed the same ground as the XTR supply ground.

    Input conditions:

    The input signals are 3.3V & 5V.


    We have to connect the external load resistance of 220 OHM, but there is no response across the load. 

  • Karthikeyan,

    In your second XTR111 circuit it looks like there are 3 different grounds. There needs to be some path from F ground to 0 ground for the XTR to function as intended.

    Other than this, I do not see anything wrong from a schematic standpoint and I would suggest investigating the board layout and whether the parts you have are damaged. You may want to verify that the output transistors are connected properly as the XTR will not function properly if these connections are reversed.