I have built and deployed many boards out into the field using the XTR116 in an isolated configuration.
This design has always worked well and is stable on the bench, but now I being told that the the 4-20 output occasionally "drifts" up to the full 20mA rail.
I cannot replicated the stated problem on the bench.
Only now am I realizing the significance of drawing 5 on page 8.
In reading the document there was no discussion on the why, when and if of this drawing.
What is un-stable operation?
Why are there two capacitors?
What are the operational differences of the two drawings?
I might be able to "hack" the board and use a 10 ohm resistor on JMPR4. This is very close to the top drawing in figure 5.
Should I increase or decrease the capacitance of a or all capacitors?
Should I remove a capacitor so that I only have two?
With a more serious "hack" I could separate the I2C rail from the MCP4725 IC and just use the VREF pin for that.
That would leave me with only one 100nF cap on the VREF pin. Would I need to add another?
If I separate the two I2C and VDD rails, and remove the capacitor, does that mean I don't need the 10 ohm resistor
Thoughts and comments are urgently needed.