AnsweredAssumed Answered

Weird AD7314 behaviour

Question asked by masterchief on Jun 5, 2012
Latest reply on Dec 17, 2012 by jtowey

Hi all,

 

I created a new discussion as the other one has been marked as "answered", and I don't kniow whether anyone would look into it anymore.

 

I am using an AD7314 to perform on board temperatrue measurement. I noticed this effect appearing a few times. It seldom happens, but it does come up once or twice.

 

To test whether the sensor is responding to temperature changes, I sprayed a cold spray (the spray that is used to cool down the circuits) around the sensor area for about 2 seconds. It reduced the temperature down to negative (around -20°C) for a brief period of time before settling to normal room temperature. When board temperature started to stabilise, I observed that the sensor returned sub zero temperature values (the 9th bit was'1') a few times before settling to the current board temperature. For example the readings would go like this 28,29,29,-0,29,-127,29,30,30,30.

 

Is this normal behaviour? Cause by perhaps abrupt temperature changes?

Outcomes