LMT70: If I use the ADC built-in CC2640R2F to work with LMT70 , can the precision be within 0.1℃？

zehua hu

Part Number: LMT70
Other Parts Discussed in Thread: CC2640R2F, LMT01, TMP116, TMP112,

For cost，my customer doesn't want to use a seperate ADC IC. If he only uses the CC2640R2F, can the precision of temperature be within 0.1℃？ Can TI provide a total solution?

Thanks!

over 6 years ago

0 Kelvin Le THS over 6 years ago

TI__Expert 6475 points

Hi Zehua,

What is the operating temperature range you are targeting?

Our device is specified to 0.13C (max) from 20C to 42C only. This doesn't account for ADC error. So your requirement of 0.1C doesn't look promising.

I did a quick calculation of the temperature error contribution from the ADC and it's about ~1C from -40C to 85C. So your system accuracy of 0.1C doesn't look like it's practical over a wide temp range.

If you want guaranteed accuracy for a wide range I would recommend looking at digital like tmp116 or LMT01 or TMP112.

-Kelvin

0 zehua hu over 6 years ago in reply to Kelvin Le THS

Intellectual 935 points

Hi Kelvin，

The product measures the body temperature. So the temperature rang will be 35~42C.

Does TI have a good total solution ? If has, can you give me a reference solution?

Thanks!

0 Jose Arteaga4 over 6 years ago in reply to zehua hu

TI__Expert 5695 points

Please check the Wearable TI design that uses the LMT70 temp sensor.
www.ti.com/.../TIDA-00824

However is not that effective since it has to use an external ADC in addition to the MCU. As kelvin mentioned please consider TMP116 for this type of application.

Regards,
Jose

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LMT70: If I use the ADC built-in CC2640R2F to work with LMT70 , can the precision be within 0.1℃？