Precision quartz oscillators have been a mainstay of embeddable timing solutions for over half a century. Crystal oscillators are flexible and rugged making them ideal for a wide range of applications. Because of the versatility there are many types of crystal oscillators with unique attributes. This paper covers oscillator types and defines and explains many of the parameters associated with crystal oscillators. Attributes and parameters such as phase noise, jitter, short term stability, long term stability, and temperature performance are all covered.
Full PDF Version
Time bases are a staple of modern electronics. They come in a variety of forms and offer an even wider variety of performance characteristics. Everything from discrete LC oscillators to atomic clocks are available for engineers to choose from, as their application's time base. Because of their inherent stability, small size, and relatively low power consumption, quartz crystal oscillators have been the industry's main solution for embeddable time bases for over half a century.
When dealing with crystal oscillators there are a variety of parameters that need to be considered and specified to ensure that the user is receiving an oscillator that meets their needs. Temperature stability, long and short term stability, frequency, and pullability are but a few of the many parameters that need to be defined when considering which crystal oscillator is appropriate. Crystal oscillators come in a variety of types and forms with each archetype possessing its own very unique attributes. It is important to understand the differences between these archetypes and what that means in terms of performance.
The following paper will discuss several topics including:
1. Brief background on quartz as time base
2. Parameter definitions
3. Crystal oscillator archetypes and their properties
Within these sections it will be shown why crystal oscillators are so widely used. The multiple forms and varying levels of stability and accuracy makes quartz a very robust and flexible choice for designing a host of solutions for a wide range of applications. For these reasons quartz will be with us for a long time into the foreseeable future, and with constant advances the quality of the timing provided by quartz will continue to improve and footprint and power consumption will continue to decrease.
The following sections are also intended to provide information in a manner such that someone with little or limited understanding of crystal oscillators will gain enough understanding of the subject to intelligently understand basic oscillator specifications.