Signal interface circuit and pressure sensor system including same

Abstract

A sensor includes groups of sense elements coupled to one another to form multiple Wheatstone bridges, each being configured to produce an output voltage across first and second output nodes. A signal interface circuit for the sensor includes switched capacitor structures, one each of the switched capacitor structures being associated with one each of the Wheatstone bridges. Each switched capacitor structure includes a capacitor having first and second terminals, a first switch for selectively interconnecting the first node of an associated Wheatstone bridge with the first terminal of the capacitor, and a second switch for selectively interconnecting the second node of the associated Wheatstone bridge with the second terminal of the capacitor. A switch state element toggles the first and second switches between a charge state and a readout state to provide a readout voltage that is equivalent to a summation of the voltage outputs of the Wheatstone bridges.