TMP117: Human contact temperature detection

Hi Jimmy,

Both the LMT70 and TMP117 can be used for measurements of body temperature and ambient temperature. 

The differences between use for body temperature measurement and ambient temperature measurement for a contact temperature sensor will only be reflected in your design/layout. For reference, you can look at Layout Considerations for Wearable Temperature Sensing, or at Layout Considerations for Accurately Measuring Ambient Temperature.

For the TMP117, you can also look at this design for multi-paramter patient monitoring systems,  or this flex patch design. 

For the LMT70 you can look at this NFC patch design, and this wearable (wrist mounted) design.

Please let me know if you have any more questions.

Best Regards,
Brandon Fisher

Hi Jimmy,

We do not have a specification for this, as it will be heavily dependent on the layout surrounding the TMP117 or LMT70. I did take some data with the TMP117EVM to give you an idea. The image below is the response from the TMP117EVM when the breakaway board is pressed against a wrist (skin sensing). The 1 time constant value is around 4.3 seconds.

Also, here is a response from the TMP117EVM going from room temperature into a 100C oven (Environment sensing). The time constant is around 14.6 seconds.

Keep in mind that these response tests are just for one set of conditions, and are n=1 sample sizes, so they wont be a complete representation. Making layout changes (such as using a thinner, or flexible PCB) will have noticeable effects on the thermal response times.

Best Regards,
Brandon Fisher