Circuiti e sistemi discreti ed integrati per l'interfacciamento di sensori capacitivi di tipo differenziale

In a reality where integrated and highly autonomous systems are adopted in any area of everyday life, great efforts are spent in the research and industrial environments so to design systems able to harvest energy from the environment around them and, in general, to maintain a very high efficiency level across all their possible working conditions. As a matter of fact, measurement subsystems (which are ubiquitous in any application field) play a significant role in this regard since, on one hand the transducer almost inevitably needs a power source to convert the measurand, and, on the other hand, being the electronic interface necessarily analog, it does not gain benefits, in terms of power consumption, from the simple technological scaling, as instead does the processing part of the complex system, typically digital. That said, on one hand it makes sense to use transducers which, by their nature, guarantee a very low power consumption and, on the other, it is worth carrying out research aimed at designing interfacing circuits that maximize readout performances avoiding spoiling the aforementioned constraints. In light of this, capacitive sensors have established in many applications, replacing the piezoresistive counterparts, since they consume virtually zero in terms of dissipated power, while not giving up in terms of robustness to temperature variations and sensitivity. The doctoral dissertation proposed here, entitled “Discrete and integrated circuits and systems for interfacing differential type capacitive sensors”, focuses on showing the state of the art and the development of new circuit and systems for the readout of differential capacitive sensors. Being a subset of the capacitive ones, this type of sensors has their same advantages while being inherently excellent at rejecting common mode disturbances.