Combined electronics and algorithm development for offset drift characterization in MEMS accelerometers

Abstract

The work discusses methods for the characterization of the sensor-related offset drift component in MEMS capacitive accelerometers. It is shown how, even with discrete electronics, it is not trivial to isolate this contribution from electronic-related components, due to unavoidable electronics tolerances and drift. A method that involves the use of multiple (at least two), nominally identical boards, pre-characterized in terms of temperature drift, is shown to be effective in identifying sensor-related drift components with an accuracy as low as sub-50 μg/K. At the same time, the developed board reaches high-resolution performance, in order to clearly highlight the Brownian noise limit (40 μg/√Hz) in the tested consumer-grade accelerometers.