Crystal Oscillator Terminology | Xsis Electronics, Inc.

CRYSTAL OSCILLATOR TERMINOLOGY

Nominal Frequency	Customer specified frequency
Frequency Accuracy @ +25 °C ( Calibration Tolerance )	Difference between the actual output frequency at +25 °C and the specified Nominal Frequency.
Frequency Stability Vs. Temperature	Maximum frequency deviation over a specified temperature range with respect to the frequency measured at +25 °C + 1 °C. This can be expressed as a percentage, PPM, or in scientific notation, e.g. + 0.005%, or + 50PPM, or + 50(10)^-6.
Operating Temperature Range	Operating temperature range over which the frequency stability and other electrical parameters must remain within their specified limits.
Aging	Long term frequency changes which are due primarily to variations in the crystal and other oscillator components.
Input Current	Current drawn by the device from the power source at a specified supply voltage.
Rise Time (TTL)	Time required for the output voltage to rise from 0.6 VDC to 2.2 VDC.
Rise Time (CMOS & ECL)	Time required for the output voltage to rise from 10% to 90% of the peak to peak output.
Fall Time (TTL)	Time required for the output voltage to drop from 2.2 VDC to 0.6 VDC.
Fall Time (CMOS & ECL)	Ttime required for the output voltage to drop from 90% to 10% of the peak to peak output amplitude.
Symmetry (TTL)	Percentage of time the output voltage is above the TTL threshold (1.4VDC Level).
Symmetry (CMOS & ECL)	Percentage of time the output voltage is above the 50% of the peak to peak output amplitude
Startup Time	Time interval for the oscillator output to reach continuos waveform to within 90 percent of the final amplitude following application of power.
Phase Jitter	Undesired deviation of a signal timing or phase from its true position. Phase Jitter can be expressed as rms or peak to peak displacement.