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TMP117: Calibrating to 0.05C (50mK) accuracy

Greg Maki
Prodigy 70 points
Part Number: TMP117

Given the characteristics of the TMP117 temperature sensor, would it be realistic to expect 0.05C accuracy over the range of -5.00 C to 40.00 C if the sensor has been calibrated by a lab? If so, would you recommend a 1, 2 or 3 point calibration?

Thank you.

  • 0
    TI__Guru* 91206 points

    Dear Greg - 

    Welcome to the E2E Forum!  -  thanks for the post

    you can expect typically +/-0.05C accuracy output from the TMP117 from -40C to 70C, with no calibration. 

    This is in the device datasheet in section 6.5, on page 5 https://www.ti.com/lit/ds/symlink/tmp117.pdf

  • 0 in reply to Josh Wyatt
    Prodigy 70 points

    Hi Josh,

    Yes, they typically have that accuracy; however, we need guaranteed accuracy. I am hoping that between the linearity of the sensor and the calibration by a lab we would get there. Also, these are to be soldered onto a PCB which, according to page 36 of the datasheet, may introduce mechanical stress that will affect the measurement error. We are minimizing the mechanical stress by NOT soldering the thermal pad.

    Best,

    Greg

  • 0 in reply to Greg Maki
    TI__Mastermind 43815 points

    Hi Greg,

    It's quite difficult to improve upon the calibration in production. Most of our customers will not accept the time/cost involved with implementing such a test. If you're serious about doing this, it should be possible with 1 point calibration for the range you're interested in. The TMP117 also provides an offset register with EEPROM behind it for your use. Having said that, we can't make any guarantees beyond the datasheet specifications.

    thanks,

    ren

  • 0 in reply to Ren Schackmann
    Prodigy 70 points

    Hi Ren,

    I am in awe of what the TI engineers have been able to do with this sensor at this price point. I do not expect TI to guarantee anything beyond what is in the data sheet. I was wanting to know if the engineers thought it would be possible to calibrate the sensor to 0.05C accuracy, given the characteristics (linearity) of the sensor and you have answered that question.

    Thank you,

    Greg