Texas Instruments Incorporated
Differential sensor using thin-film piezoelectric capacitors

Abstract:

An improved differential sensor and corresponding apparatus implementing same. The differential sensor includes a substrate, an amplifier coupled to the substrate, and a plurality of highly-matched piezoelectric capacitors formed onto the substrate. A first set of the highly-matched piezoelectric capacitors are electrically coupled to a non-inverting input of the amplifier, and a second set of the highly-matched piezoelectric capacitors are electrically coupled to an inverting input of the amplifier to form an open loop differential amplifier.