Can we "deGauss" the LIS2MDL using register commands to reset the AMR when exposed to high field to remove large hard iron offsets? The MMC5983MA allows this, does the LIS2MDL?

[KWine]

We have noticed that several LIS2MDL have come back to us with very large magnetic field offsets. While these can be corrected by the usual offset calibration, the large offsets are due to exposure to a large magnetic field source somewhere in the environment. We would like to be able to remagnetize the anisotropic MR film to recover its factory magnetization. Is this possible using the embedded current drivers for the offset cancellation in the LIS2MDL? The MMC5983MA offers this feature. We would like to use it for the LIS2MDL if available.

[Eleon BORLINI]

Hi @Kristel Wee​ , I would have suggested you the standard offset cancellation procedure as described in the AN5069 app note... but it seems you have already tried it. How strong is the residual magnetization of your samples? IS it above or as great as the magnetic field dynamic range of ±50 gauss? Regards

[KWine]

We don't precisely know. We can correct the magnetometers using our calibration methods after the new "set" is taken, it is just that some field exposure is causing the AMR to take on rather large new default field values negating the previous calibration. In the MMC5983, it is possible to run a current near the AMR to "remagnetize" the film and get back to a more or less default configuration. The LIS2MDL has similar strapping currents in order to effect the dynamic offset correction, but perhaps the currents are not large enough to reset the AMR?

I suppose our concern is non-linear or other sub-optimal performance of the LIS2MDL if the AMR takes a large deviation from the nominal (factory) magnetic field settings. Being able to periodically reset the AMR would be a useful feature. How is this done in production?