Generating clock frequency - involves generating clock frequency depending on reference frequency in form of mains power supply network frequency, e.g. by deriving from mains hum frequency

摘要

The method involves generating the clock frequency (fT) depending on a reference frequency (fref). The reference frequency is the mains frequency of a power supply network. The reference frequency can be derived directly from the mains a.c. voltage or from the hum voltage produced by the mains supply.