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TMP61: The Vtemp has offset issue

Part Number: TMP61

Hi team

Our customer is testing TMP6131DYAR, but we found there is offset on the output result. Temp=26degree, Rbias=10k(1%,9.97kohm actual). The test results are as below:

Vbias/V Ideal Vtemp/V Test Vtemp/V Offset/V
2.5 1.25 1.32 0.07
3 1.5 1.58 0.08
3.5 1.75 1.83 0.08
4 2 2.09 0.09
4.5 2.25 2.35 0.1
5 2.5 2.6 0.1

Do you have any insights about this issue?

  • Hi,

    Thanks for posting to the Sensors forum!

    • Can you provide more details about the customer's test setup? Are they testing the device in a stable temperature environment like a temperature chamber or oil bath? What are they using as a temperature reference? How are they measuring Vtemp?

    • Can you share a schematic and/or layout? Are there any devices near the TMP6131DYAR that could be affecting the temperature or adding noise to the measurements?

    • Is your customer using the 4th order polynomial TMP vs Vdc from the Thermistor Design Tool to evaluate the TMP6131DYAR? If not, they can download the tool and open the Voltage Bias version.

      On the "Main" tab, select the device and enter the Vbias voltage (shown below).



      Then, go to the "4th Order Polynomial TMP vs. Vdc" tab to see the 4th order polynomial equation and coefficients that is used to convert Vtemp to temperature. There is also an area to enter a Vtemp and see the expected calculated temperature that may be helpful to get the most accurate "Ideal Vtemp" in their evaluation.

    Best regards,

    Jesse