Introduction: The advent of integrated circuits, which became possible because of the tremendous progress in
semiconductor technology, resulted in the low cost microprocessor. Thus if it is possible to design a low
cost sensor which is silicon based then the overall cost of the control system can be reduced .We can have
integrated sensors which has electronics and the transduction element together on one silicon chip.

This complete system can be called as system-on-chip .The main aim of integrating the electronics and the
sensor is to make an intelligent sensor, which can be called as smart sensor. Smart sensors then have the
ability to make some decision. Physically a smart sensor consists of transduction element, signal
conditioning electronic and controller/processor that support some intelligence in a single package. In
this report the usefulness of silicon technology as a smart sensor, physical phenomena of conversion to
electrical output using silicon sensors, characteristics of smart sensors. A general architecture of smart
sensor is presented.