S-Type Voltage Controlled Crystal Oscillator

Vectron International 267 Lowell Rd, Hudson NH 03051

Tel:1-88-VECTRON-1

e-mail: vectron@vectron.com

Qualification Conformance

The S-Type has undergone the following Mil-Std qualification.

Table 3. Environmental Compliance

Parameter

Conditions

Mechanical Shock

MIL-STD-883C 2002.3, TEST B

Mechanical Vibration

MIL-STD-883C 2007.1, TEST C

Solderability

MIL-STD-883C 2003.5

Gross and Fine Leak

MIL-STD-883C 1014.7, 100% Tested

Resistance to Solvents

MIL-STD-883C 2016

Handling Precautions

Although ESD protection circuitrry has been designed into the the S-Type, proper precautions should be

taken when handling and mounting. VI employs a human body model and a charged-device model (CDM)

for ESD susceptibility testing and design protection evaluation. ESD thresholds are dependent on the

circuit parameters used to define the model. Although no industry wide standard has been adopted for the

CDM, a standard HBM of resistance=1.5Kohms and capacitance = 100pF is widely used and Therefore

can be used for comparison purposes.

Table 4. ESD Ratings

Model

Minimum

Human Body Model

1500 V (Mil-STD-883D, Method 3015, Class 1)

Charged Device Model

1500 V

Absolute Pull Range (APR) Specification

The frequency deviation of the S-Type VCXO is specified in terms of Absolute Pull Range (APR). APR

provides the user with a guaranteed specification for minimum available frequency deviation over all

operating conditions. Operating conditions include operating temperature range, power supply variation,

differences in output loading and changes due to aging.

An S-Type VCXO with an APR of +/-50 ppm will track a +/-50 ppm reference source over all

operating conditions. The same device will typically demonstrate a Total Pull capability of 150 to

350 ppm. Absolute Pull Range (APR) is specified by the fourth character of the product code in Table 6.

Please see Vectron’s web site, www.vectron.com, for the APR Application Note.

Oscillator Aging

Quartz stabilized oscillators typically exhibit a small shift in output frequency during aging. The major

factors which lead to this shift are changes in the mechanical stress on the crystal and mass-loading of

foreign material on the crystal.

As the oscillator ages, relaxation of the crystal mounting stress or transfer of environmental stress

through the package to the crystal mounting arrangement can lead to frequency variations. VI has

minimized these two effects through the use of a miniature AT-Cut strip resonator crystal which allows a

superior mounting arrangement and results in minimal relaxation and almost negligible environmental

stress transfer.