Digital frequency synthesiser - controls denominator of frequency divider and converts manual analog control signal into digital value for storing in memory

摘要

The synthesiser has a programmable frequency divider. A manual analog control signal is converted into a digital control signal and stored. The stored digital control signal is passed as an integer to the frequency divider. The magnitude of the difference between the analog control signal and the analog equivalent of the stored digital signal is formed. The memory is updated using the digital control signal depending on whether the difference determined previously exceeds a given magnitude. The advantage lies in the programming signal being kept constant regardless of slight or insignificant changes in the analog control signal. The synthesiser may be used in broadcast receivers or for controlling motors.