Voltage-mode analog interfaces for differential capacitance position transducers

A fully-analog integrated electronic interface for the detection and measurement of differential capacitive position sensors is shown. The read-out circuit, performing a differential capacitive to voltage conversion, has been developed in a standard 0.35 μm CMOS technology with low-voltage/low-power characteristics. The interface has shown a good accuracy, in particular the relative percentage error is lower than 0.8% for the simulations of the integrated solution. When compared to other solutions in the literature, sensitivity (S) and resolution (res) data on a practical case-study of position sensor are satisfactory so validating the architecture to be a good candidate as first stage in analog front-ends for differential capacitive sensor data measurements.