Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten.

Generation of frequency output for instrumentation applications using digital hardware

: Zamora, M.; Henry, M.; Peter, C.


Sensor review 23 (2003), No.2, pp.143-149
ISSN: 0260-2288
Journal Article
Fraunhofer IGD ()
automation; communication technology; process control system; digital frequency generation

The use of frequency output for measurement transmission remains common in the design of smart transmitters. Conventional methods of frequency generation, based on counting clock cycles, have a precision which is inversely proportional to the frequency to be generated. Consequently, frequency output precision could be much lower than the measurement precision. This paper describes a simple frequency generation technique which, when implemented in low-cost hardware, provides a precision of 10-6 per cent for all frequencies. The method represents an intermediate non-available frequency by dithering between two exact frequencies. Averaging over some reasonably short timescale provides the desired frequency to high precision.