Digital phase and frequency control - uses oscillator in circuit with phase comparator frequency integrator and correction signals decided by counter

摘要

The circuit arrangement comprises a control oscillator (10) which regulates a counter (12), and this in turn is connected to a phase comparator (20) which receives the incoming signal. Output values in terms of phase and frequency corrections are fed back to the counter, the latter through an integrator. The pulse counter (12) has a number of AND gate elements connected in a series-parallel arrangement. A forwards-backwards counter is used by the frequency indicator. The circuit arrangement enables threshold values to be computed so that synchronisation in the counting process may be achieved with the frequency of the oscillator.