Anwendungsinformationen
Kristallresonatoren
The importance of quartz crystal resonators in electronics results from their extremely high Q, relatively small size and excellent temperature stability.
A quartz crystal resonator uses the piezoelectric properties of quartz. The direct piezoelectric effect refers to the electric polarization of certain materials brought about by the application of mechanical stress.
Zeiteinhaltung
Since its introduction the 32.768 kHz miniature watch crystal has become the most popular time keeping reference ever. This application note is intended to give some guidance as to the use of quartz crystals in time keeping applications.
In almost all circumstances designers will want to use simple logic gate oscillators for this application for the sake of convenience and cost. The criteria normally applied to this type of design are that it should be accurate, low in cost and low in power consumption. Using a watch crystal and CMOS logic all these criteria can be met.
Jitter
Measuring and specifying jitter using a phase noise plot for a crystal oscillator that contains only random jitter sources has several advantages over conventional time domain methods using high-speed digital sampling oscilloscopes (DSO’s).
The jitter performance of the oscillator is often much better than the combined jitter uncertainty of the DSO’s internal sampling oscillator, the DSO’s trigger point uncertainty and some questionable software techniques.
Erläuterung Quarze
A typical surface mount quartz crystal specification reads like this:The following notes define each element of the specification:FrequencyFrequency is normally specified in kilohertz (kHz) up to 999.999kHz and in megahertz (MHz) from 1.0MHz. All…
Erläuterung Oszillatoren
A typical surface mount Clock Oscillator specification reads like this:The following notes define each element of the specification:FrequencyFrequency is normally specified in kilohertz (kHz) up to 999.999kHz and in megahertz (MHz) from 1.0MHz. All…
Erläuterung MEMS Oszillatoren
IntroductionMicro Electro Mechanical Systems or MEMS as it is commonly known is the latest technology to be used in the Frequency Products market as an alternative to quartz based devices.MEMS devices use a “silicon-beam” rather than quartz as…
Specifying Programmables
A typical surface mount programmable oscillator specification reads like this:The following notes define each element of the specification:FrequencyFrequency is normally specified in kilohertz (kHz) up to 999.999kHz and in megahertz (MHz) from…
Specifying VCXOs
A typical VCXO specification reads like this:The following notes define each element of the specification.FrequencyFrequency is normally specified in kilohertz (kHz) up to 999.999kHz and in megahertz (MHz) from 1.0MHz. All our computer-generated…
Specifying TCXOs
A typical TCXO specification reads like this:The following notes define each element of the specification.FrequencyFrequency is normally specified in kilohertz (kHz) up to 999.999kHz and in megahertz (MHz) from 1.0MHz. All our computer-generated…
Specifying OCXOs
The following notes define each element of an OCXO specification. An OCXO is generally used when a very stable frequency is required.FrequencyFrequency is normally specified in kilohertz (kHz) up to 999.999kHz and in megahertz (MHz) from 1.0MHz. All…
Frequenzspezifische Fragen
• Was ist ein piezoelektrischer Effekt?Quarz-Kristalle sind abhängig vom piezoelektrischen Effekt um zu funktionieren. Die Basis ist ein Quarz-Resonator mit einer Elektrode auf beiden Seiten, welche in einem versiegelten und beschichteten Halter…