Hello,
When using XTR117 in an application that outputs a 4-20mA signal (under region of concern), but rails at ambient conditions (going to the XTR117 current limit), I observed some of the current transmitters appear to latch.
I modified a transducer circuit (disabling the sensor input and replacing it with a DC supply). The transmitter behaves nominally when in the 4-20 mA range (.2-1V). However, when the signal voltage reaches ~1.40-1.45 V (which happens when the sensor goes to ambient conditions) the transmitter will no longer follow input voltage (staying near ~32-35mA, even if the input voltage goes back down).
I'm not concerned with the response of the transmitter outside of the 4-20mA range, so long as it returns once the signal drops to 1V. After the output latches and the input signal is reduced below the ~1.4V, cycling the power will cause the transmitter to respond again (until going above ~1.40-1.45V).
This happened with a few of the transmitters that I've used for this application. I'm curious why this happened to only a couple of the transmitters and if there is any suggested way to prevent it from happening.
Thanks,
Brian