Freescale Semiconductor,inc.

Thomas D Ohe

Dubravka Bilic

Marco Fuhrmann

Liviu Chiaburu

Marco Fuhrman

A sensor system () includes transducers () each yielding an analog signal () representing a parameter independently sensed by each of the transducers (). The signals () are summed and the resulting transducer signal () is converted to a digital transducer signal () by a high resolution analog-to-digital converter (ADC) (). Concurrently, one of the signals () is subtracted from the other. The resulting difference signal () is converted to a digital difference signal () by a low resolution ADC (). When the digital difference signal () is within a threshold window (), a fault signal () indicates a normal condition () of the transducers (). When the signal () falls outside of the threshold window (), a fault signal () indicates a fault condition () of the transducers. The transducer and fault signals () are concurrently output from the sensor system ().

Dual sensor system having fault detection capability

A pressure sensor includes a first set of electrodes, a second set of electrodes, and a common electrode. The first and second sets of electrodes overlie an insulative surface, wherein the first set of electrodes represent sense capacitor bottom electrodes and the second set of electrodes represent reference capacitor bottom electrodes. The second set of electrodes is configured in an interleaved arrangement with the first set of electrodes, wherein the geometry of individual electrodes of the first set of electrodes substantially matches the geometry of individual electrodes of the second set of electrodes. In addition, the common electrode represents a sense and reference capacitor top electrode that is (i) overlying, (ii) spaced from, and (iii) configured in connection with the first and second sets of electrodes to form a common pressure cavity, wherein the common electrode includes first portions corresponding to sense membrane portions and second portions corresponding to reference membrane portions, further wherein an area of a sense membrane portion is greater than an area of a reference membrane portion.

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Tempe, AZ, United States of America

Thomas D Ohe