As the frequency of a crystal oscillator increases it becomes increasingly difficult to produce
high stability resonators. Over a period of about 20 years, the frequency of the state-of-the-art
high performance crystal oscillators has increased from 100 k Hz to I MHz, then to 5 MHz.
Currently 10 MHz is the most common frequency available in the highest performance crystal
oscillators. Although 10 MHz has become accepted as the standard crystal oscillator
frequency, there are still many applications in communications, navigation, and
instrumentation which require 5 MHz, I MHz or other frequencies. Many times the system
designer would like to have a local oscillator or timebase which is not a standard frequency.
The choices are either to purchase a special frequency oscillator, often at a significant cost
increase, or to design special interface circuitry to take advantage of the standard frequency
oscillator. The purpose of this a|