3-axis high Q MEMS accelerometer with simultaneous damping control

Lavinia Ciotîrcă (1, 2) , Olivier Bernal (1) , Hélène Tap (1) , Jérôme Enjalbert (2) , Thierry Cassagnes (2)

1 LAAS-OSE - Équipe Optoélectronique pour les Systèmes Embarqués
2 NXP Semiconductors [France]

The increasing demand of consumer market sensors involves a continuous development for the die size, cost and performances. In this context, the integration of both a 3-axis MEMS accelerometer and a gyroscope within the same low pressure cavity becomes attractive. Such a packaging results in MEMS with high quality factor Q, which reduces Brownian noise, thereby improving the achievable precision. However, contrary to gyroscopes, in such a configuration, the MEMS accelerometers need to be damped prior to measurement. Therefore, this paper presents a new damping control architecture for such high Q capacitive accelerometers. Damping is ensured by inserting electrostatic force feedback (EFF) phases between measurement phases. By simultaneously damping 3 axis of acceleration, the transducer settling time is improved. Model simulations results prove damping efficiency and figure out a tradeoff between system sampling frequency and circuit complexity.

Mots clés: Inertial; sensors; MEMS; accelerometers; electrostatic damping; multi-axis simultaneous control

Domaines: Micro et nanotechnologies/Microélectronique

Lavinia Ciotîrcă, Olivier Bernal, Hélène Tap, Jérôme Enjalbert, Thierry Cassagnes. 3-axis high Q MEMS accelerometer with simultaneous damping control. New Circuits and Systems Conference (NEWCAS), 2016 14th IEEE International, Jun 2016, Vancouver, Canada. pp.1 - 4, ⟨10.1109/NEWCAS.2016.7604787⟩. ⟨hal-01488286⟩