Electronic processing of transducer signals: hall effect as an example

Abstract The distribution of electronic processing power between the transducer, the interface electronics and the central processor is discussed. As an example, the case of a Hall effect magnetic transducer is presented. The Hall device takes the form of a split drain MOS transistor that is incorporated within a custom chip, together with some interface electronics to translate the magnetic field information ratio into a frequency difference. This form of coding provides robust information transmission with inherent structural compensation for common mode errors and suitability for microprocessor interfacing without the use of A–D converters. The sensor chip is mounted on a thick-film hybrid circuit together with a microprocessor and some minor components to yield a miniature component with full internal compensation that is capable of communicating with a host system by means of a protocol realized in clear ASCII format.