Programmable digital phase control for transceivers - has synchronised oscillator working as clock source and feeding binary counter

摘要

The programmable numeric phase control is based on a purely numeric phase loop esp. for use in numeric data receivers and transmitters. A local oscillator working at a frequency which is high compared to that of the input energises a binary counter. This has an oscillator stage working at the input signal frequency acting as the local clock source. A counting circuit is corrected each time an input pulse arrives maintaining the clock source in synchronism. The circuit memory is programmed such that phase changes are controlled providing a fast response time and immunity to inherent noise.