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LIS3MDL high nonlinearity for negative magnetic fields

Question asked by sanchez_chiva.josep_ on Sep 16, 2015
Latest reply on Oct 21, 2015 by J
Hi all,

I am testing a board that uses a LIS3MDL as a magnetic reference sensor communicating with a 3-wire SPI. I am testing the sensor using a Helmholtz coil that I built (that, by the way, has been tested and generates correctly the magnetic field).

When reading the magnetic data from the LIS3MDL I see that magnetic data tracks correctly the generated magnetic field for positive fields. However, negative magnetic fields are not correctly measured and show a different slope in a Breal vs B measured plot. This error in the measurement is far higher than the +-0.12% nonlinearity expected from this device.

I have tested three prototype boards and all of them have this issue. I have studied the raw binary data coming from the sensor and I have discarded any conversion from binary to Gauss error.

So finally, my question is: Is this performance normal? Are the three sensors damaged in the same way? Has anybody had the same problem? Should I give up and work with it?