Dierential read-out circuit for capacitive sensors

Capacitive sensors have the capability to fit with a wide variety of detection and measurements problems. These devices detect mechanical quantities by means of displacement measurements. They are present in various consumer goods, such as mobile phones, laptops, and so on. However, their main limitation is represented by the design complexity of the sensor interface. In fact, being passive sensors, they need an active circuit to generate an output signal. Focus of this thesis is to study and design such a circuit with differential read-out with good performances in terms of noise, linearity and power consumption. The chosen interface makes the sensor work between two nodes with a fixed voltage. In this condition, the input signal for the active circuit is a current