Influence of magnetic fields in MEMS accelerometers

[Guille]

Good morning,

I would like to know if measurements of MEMS accelerometers/inclinomteres are influenced by near static magnetic fields.

The question is generic but regards particularly the model IIS2ICLX.

Thanks for the attention.

[Eleon BORLINI]

Hi @Guille​ ,

no, ST inertial sensor such as accelerometers are not influenced in their parameters by the exposure to a magnetic field (if it is not very huge, but this is not a practical use case), since the mechanical structure is capacitive and the physical principle is linked to electrical charge variation on the capacitor digits.

-Eleon

[Guille]

Hello Eleon,

The MEMS could be positioned very close to a strong magnet, and I was wandering if that could somehow influence the MEMS accuracy.

Can you quantify what is the meaning of "very high"? Did you make some practical experiments bringing a magnet close to the MEMS and observing possible effects on measurements?

As far as I remember from my studies on physics, moving electrical charges do interact with statics magnetic fields, but I am not able to evaluate if it is negligible or not in this particular case.

Thanks for your support.

G

[Eleon BORLINI]

Hi @Guille​ ,

ST produces magnetometers embedded in accelerometers, such as the LSM303AGR, and the limit for the magnetometer only in that case is 1T (for permanent magnetization). The disturbing field should be very high, for example Neodymium magnets don't influence the accelerometer.

-Eleon