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TMP275: Isolated (from GND) Temperature Sensor Recommendation

Part Number: TMP275

I need a temperature sensor recommendation with the following key specification:

3.3V Powered

I2C Interface with at least four addresses

-10 to 85°C range (min)

Isolated from ground sensing.

The last requirement is important and I originally picked the TMP275.  It meets all of my requirements but it says to mount it on a PCB and use the copper pad connect to the end pin of the TMP275 as the main contact for sensing temperature.  The problem is that I want to sense temperature on a metal object that I don't want to connect to GND.  Does anyone have a better part suggestion for this application?  Thanks.

  • Hi Rick,

    Thanks for posting to the Sensors forum.

    I believe you are referring to the ground plane shown in section 10.2 of the TMP275 datasheet:

    The ground plane for thermal coupling to the heat source is suggested to ensure that the measured temperature from the sensor is as close as possible to the actual temperature of the heat source, but the ground plane to the heat source isn't strictly necessary.

    You can still use the TMP275 to measure the temperature of the metal object without the ground plane to it, you'll just have slightly more thermal resistance than you would with the plane. Make sure the TMP275 is placed as close as possible to the heat source.

    Best regards,