TMP112: test error

Lillian Liu(SH)

Part Number: TMP112

Tool/software:

Hi team，

When testing the function of this temperature sensor, I found that there was an error of about three degrees between the data read by the software and the actual viscometric temperature line.

TMP112 is a local sensor and can only accurately measure the temperature under the IC. However, the customer's temperature measurement line is stuck in the middle of the sensor top surface. We cannot measure the temperature line directly under the IC. Is there any fixture that can measure it? Or can the two temperatures be converted?

Additionally, what else needs to be checked to confirm where the error comes from?

Thanks

Lillian

11 months ago

0 Ren Schackmann 11 months ago

TI__Mastermind 43875 points

Your application requires thermal coupling of the sensor to the object being measured. If the PCB provides a lot of metal around the sensor, it will conduct heat away from the sensor, creating a thermal gradient. Close attention to mechanical design is needed to ensure accuracy.

Minimize distance and maximize conductivity of materials between the sensor and the object you wish to measure.
Minimize mass of the sensor assembly. To achieve this, use flex PCB or PCB cut-outs around the sensor and limit copper traces/planes.

You may be able to characterize the gradient in your system to "calibrate" it. You should consider the full range of temperatures the end equipment is expected to operate in, as the gradient could change.

thanks,

ren

0 Lillian Liu(SH) 11 months ago in reply to Ren Schackmann

TI__Expert 4620 points

Hi Ren，

Regarding the thermal gradient you mentioned, could you tell me the formula?

Thanks

Lillian

0 Ren Schackmann 11 months ago in reply to Lillian Liu(SH)

TI__Mastermind 43875 points

If you want to model the gradient in your system, you need to use a thermal modeling tool like ANSYS or Cadence Celsius.

If you want to "calibrate" your system, you need to collect the data for expected input/output and use curve fitting techniques.

thanks,

ren

0 Lillian Liu(SH) 11 months ago in reply to Ren Schackmann

TI__Expert 4620 points

Hi Ren,

OK, I understand. So how did TI verify the functionality of this material in actual application? Is there a test report?

Thanks

Lillian

0 Ren Schackmann 11 months ago in reply to Lillian Liu(SH)

TI__Mastermind 43875 points

Which material are you referring to? I don't think there is a report for what you're looking for.

thanks,

ren

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TMP112: test error