We are currently using an AD8495 with a K type thermocouple in our portable medical device. The circuit works great...simple to use and easy to configure. However, the recommended break detection configuration drives the output of the amplifier to the positive rail. This works in many applications but unfortunately not in ours. We want the output of the amplifier to go to GND when the thermocouple breaks or is open. Any suggestions?
+Vs = 3.3vdc
-Vs = GND
Vref = GND
Sense is tied to the output
There is a 1M ohm resistor to GND at the thermocouple connector
Our circuit is exactly like figure 33 in the datasheet.
Thanks in advance!!