This paper discusses the state-of-the-art and current trends in the de
sign of intelligent low-cost high-performance sensor systems. In these
systems the functions of the sensors, actuators, analog interfacing c
ircuits and microcontrollers are merged in overall designs which have
been implemented, where technology allows, on common substrates. Impor
tant properties which can act as focus points for an intelligent desig
n are: adaptability, accuracy, dynamic range, speed, power consumption
, reliability and costs. The functions of A/D converters are re-evalua
ted and novel conversion methods presented. Some important aspects of
data processing and data communication are discussed. Examples of inte
lligent sensor systems are given in two areas: smart temperature senso
rs which can detect the presence of micro-organisms in food products b
y sensing the temperature rise of the products with a resolution of 5
mK, and capacitive displacement transducers which can accurately sense
position, speed and acceleration by measuring the (trans)capacitances
in multi-electrode structures.