TMAG5173-Q1: Sensitivity lifetime drift and drift estimation

Marko Ollikainen

Part Number: TMAG5173-Q1
Other Parts Discussed in Thread: TMAG5273,

Tool/software:

Hello support team,

We are considering of using TMAG5173A2 (or TMAG5273) to monitor magnetic field generated by a magnet for a time period of few years. The absolute accuracy is not as crucial as stability/repeatability of measurement.

We would like to learn more about the sensitivity specifications shown in datasheet.

A sensitivity error specification at certain temperature gives a maximum error of 3.3%. Is this sensitivity error something that remains more or less constant through the lifetime of the component or does this sensitivity error change through the years? For example, if the error of a sensor in the beginning is 2%, is it ok to assume that after 2 or 5 years this error is still 2% in this sensor, if temperature is kept constant?

Another spec is Sensitivity lifetime drift with max. value of 4.9%. This drift spec clearly suggests that sensitivity will change in time. But what is this "lifetime"? Is there a way to estimate this drift for example after 2 or 5 years? Is it a linear function of time? Also, is this lifetime sensitivity drift something that needs to be added to sensitivity error, so that the overall maximum drift could be in the order of 3.3% + 4.9 % after some period of time? Or how could we estimate the total drift of sensitivity as a function of time?

Texas also has a model TMAG5273A2. For this model the datasheet does not specify sensitivity lifetime drift. Is it ok to assume that lifetime drift for TMAG5273 is somewhat similar to TMAG5173, since these models seem to be some sort of "siblings" in many ways?

Best Regards,

Marko

27 days ago

0 Alicia Rosenberger 27 days ago

TI__Genius 14290 points

Hi Marko,

Thank you for posting to the Sensors forum!

Marko Ollikainen said:
Is this sensitivity error something that remains more or less constant through the lifetime of the component or does this sensitivity error change through the years?

The sensitivity error should remain fairly constant throughout the lifetime of the component.

Marko Ollikainen said:
what is this "lifetime"? Is there a way to estimate this drift for example after 2 or 5 years?

The "lifetime" number is based on the before and after testing during the qualification process of the device. The actual standards that any TI device are qualified under can be looked up here:

Qualification summary

For the TMAG5173A2QDBVRQ1, the accelerated lifetime testing was done at 125°C for 1000hrs per JESD22-A108. The actual equivalent expected lifetime depends on the user's application, but these tools are intended to help estimate that:
MTBF/FIT estimator

Temperature change FIT

Marko Ollikainen said:
Also, is this lifetime sensitivity drift something that needs to be added to sensitivity error, so that the overall maximum drift could be in the order of 3.3% + 4.9 % after some period of time?

Sensitivity lifetime drift refers to how the overall slope of the sensitivity linearity error may change over the operating life of the device. So over time, the sensitivity lifetime drift should be added to the sensitivity linearity error.

Marko Ollikainen said:
Texas also has a model TMAG5273A2. For this model the datasheet does not specify sensitivity lifetime drift. Is it ok to assume that lifetime drift for TMAG5273 is somewhat similar to TMAG5173, since these models seem to be some sort of "siblings" in many ways?

The TMAG5273 device is fairly similar to the TMAG5173-Q1, so it would be fair to assume that the lifetime drift for the TMAG5273 would be somewhat similar to the TMAG5173-Q1.

Best,

~Alicia