MICROCIRCUIT CRYSTAL OSCILLATOR TERMINOLOGY

Nominal Frequency	Customer specified frequency
Frequency Accuracy @ +25 °C (Setting and/or Calibration Tolerance)	How close to the specified frequency the output frequency is factory adjusted at +25 °C.
Frequency Stability Vs. Temperature	The 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	The operating temperatures 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	The current drawn by the device from the power source at a specified supply voltage.
Rise Time (TTL)	The time required for output voltage to rise from 0.6 VDC to 2.2 VDC.
Rise Time (CMOS & ECL)	The time required for output voltage to rise from 10% to 90% of the peak to peak output.
Fall Time (TTL)	The time required for output voltage to drop from 2.2 VDC to 0.6 VDC.
Fall Time (CMOS & ECL)	The time required for output voltage to drop from 90% to 10% of the peak to peak output amplitude.
Symmetry (TTL)	The percentage of time the output voltage is above the TTL threshold (1.4VDC @ +25 °C).
Symmetry (CMOS & ECL)	The percentage of time the output voltage is above the 50% of the peak to peak output amplitude