How to handle e-Compass thermal drift

[Central SUPPORT]

We do some initial validation of LIS3MDL and experienced a problem when we do a temperature cycle (20°C to 80°C in 20 minutes) in an oven with 7 sensors inside and no external magnetic field present.

It seems that we get an offset in the output signal. We have tried to enable the TEMP_EN bit, but the output is more or less the same. In fact, the output does not return to "normal" when the temperature returned to room temperature.

Do you have an idea how to fix this problem?

NOTE: This question and answer originated from a customer support case which was handled by us. We regularly review support cases and add any helpful ones here for all to benefit from.

[Central SUPPORT · Accepted solution]

For LIS3MDL please consider that embedded temperature compensation can be used to reduce the thermal drift of the sensitivity, while it is not able to compensate the thermal drift of the offset. About offset thermal drift, your observation is correct, it can be up to few mG/°C (linear dependence).

LIS3MDL is a TMR sensor where only set pulses mechanism is present, that's why you cannot compensate thermal offset drift. New products like LSM303AGR are AMR technology sensors where a set/reset mechanism is available which is able to remove offset thermal drift. This means that the difference is that in AMR we are able to drive current pulses in two opposite directions alternatively (which is used to cancel offset), while in TMR the current pulses can be driven just in one direction.

[Atahe.2113]

Hello, i have a LSM303AGR sensor. According to what understood from this answer, i expect that my sensor x and y and z output (separately) be constant on various temperature (-40 °C to +85 °C), because of removing offset thermal drift. But that is not so and x,y and z components

varies over temperature. How to solve this problem?