This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TMAG5170: TMAG5170A2 wrong max range (as in TMAG5170A1)

Part Number: TMAG5170

Hi.
I worked with 5170A1 for some time (max range + -100 mT).
Everything was functioning normally.
Immediately after the release of version A2 (max range + - 300 mT), I ordered and received new chips in early October.
The marking is valid A2, defined as A2.
But !!!
when measuring magnetic fields, the maximum range still does not exceed + - 100 mT.
Here are the images of the chip and the state of the registers.
What can be wrong?

Regards,

Alexander

  • Alexander,

    From your register readout it looks like the output is nearly at the FS code for all three axes.  Can you provide more details on your magnetic field input?  If the field you are testing with saturates both device variants then you would see similar behavior on the output.  Are you measuring against a known reference? 

    Thanks,

    Scott 

  • Hello Scott.


    If I understood correctly, the A2 version differs from the A1 by a 3 times reduced gain (326 LSB/mT to 108).
    That is, if I just replace the A1 chip with A2, I have to check the TEST_CONFIG register myself, and if the A2 version is found, multiply the result of the magnetic field measurement by 3. Is that so?

    Regards,

    Alexander

  • Alexander,

    Yes.  The output result will be converted at differing gain between the three ranges of the device and each device variant by a factor of 3.  So the output code on the A1 device should be 3x larger than the code from A2 with an identical field. However, if both devices experience a field >300 mT, then both devices would saturate and then the result would be an identical output code.

    If you have the ability to test A1 at the same time as A2, you should be able to test the difference between the devices by placing a magnet far enough away from the sensors so that they both observe an input below 100 mT and then compare the output result.  You should then be able to move the magnet closer and see A1 saturate while A2 still has headroom to accept larger field inputs at the same range.

    Thanks,

    Scott