A novel micromachined accelerometer capacitive interface

In this paper a feasibility study of a novel interface concept is described for the design of a closed-loop accelerometer based upon a micromachined capacitive sensing element. The approach combines the advantages of the simple signal pick-off arrangement typically used for analogue accelerometers with those of accelerometers based upon an oversampling technique or sigma-delta modulation, which include direct digital output signal, an inherent self-test feature and improved system stability. The interface circuitry is low in component count, which makes it particularly suitable for prototype evaluation, yet has the potential for a high-performance device.

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