Glossary / Definition of Terms
(VCXO / TCXO)

Control Voltage - An external voltage applied to a VCXO or TCVCXO that results in a specified change in frequency.

Control Voltage Range - Specified range of the control voltage that will change the frequency.

Deviation - The frequency change caused by a change in the Control Voltage from the Nominal Control Voltage, over the specified range.

Frequency Calibration - Factory room temperature (25°C) adjusted frequency tolerance.

Frequency Tolerance - The specified worst case operating frequency relative to calibration, temperature, voltage, load and aging conditions, where the Control Voltage equals the Nominal Control Voltage.

Incremental Deviation Sensitivity - The frequency slope (ppm/V) resulting from 10 equally spaced control voltages within the specified voltage range.

Maximum Deviation - The maximum change in frequency at Control Voltage minimum and Control Voltage maximum relative to Nominal Control Voltage.

Minimum Deviation - The minimum change in frequency at Control Voltage minimum and Control Voltage maximum relative to Nominal Control Voltage.

Modulation Bandwidth - The minimum +/-3dB bandwidth frequency, relative to a 1 KHz input modulation frequency.

Negative Transfer Function - A negative change in frequency, with a corresponding positive change in Control Voltage.

Nominal Control Voltage - Specified center of the Control Voltage Range.

Nominal Frequency - User specified oscillator frequency at Control Voltage equals Nominal Control Voltage.

Operable Temperature Range - Temperature Range over which a unit will operate, but not necessarily meet all published specifications.

Operating Frequency - The actual frequency output with respect to the actual operating conditions of temperature, voltage and load.

Operating Temperature Range - Temperature Range over which a unit is guaranteed to operate and maintain published specifications.

Positive Transfer Function - A positive change in frequency, with a corresponding positive change in Control Voltage .

Tuning Limits - The minimum and maximum frequencies attained by adjusting Control Voltageover, Control Voltage Range inclusive of the specified frequency stability, Frequency Tolerance. The minimum limit is [fcmax-ftol]. Minimum Tuning Limit is also commonly referred to as "Capture Range","Absolute Pull Range", or "Usable Deviation".

General Deviation-

Measurements

(reference MIL-0-55310)- The data necessary to calculate Deviation, Incremental Deviation Sensitivity, and Deviation Linearity are output frequency readings as a function of Control Voltage f(Vc). Assuming that Vcnom is midway between minimum Control Voltage and maximum Control Voltage, then the prescribed incremental Control Voltage (Vcn) settings, where the corresponding frequency, f(Vcn) is recorder can be calculated by:

Incremental Control Voltage(Vci)=

Vci = (Vcmax-Vcmin)/ 10 (10 equally spaced increments)

Then: Vcn=Vcn-1 + Vci, where n= the increment and let Vc1=Vcmin

The chart below (Table 1)