G-sensitivity is defined as a change in frequency resulting from an acceleration force applied to an oscillator. It is often expressed in terms of ppb/g. How does this affect performance? When an oscillator is used in an environment conducive to vibration, the frequency of the vibration will modulate the carrier frequency degrading the phase noise performance of the oscillator. This phenomenon is similar for both random and sine vibration and is also very deterministic meaning the magnitude of the induced phase noise degradation can be calculated if the g-sensitivity of the oscillator is known. John Vig has written an excellent tutorial on quartz crystals and resonator stabilities [1]. Please follow the link to an excerpt from John's tutorial which will provide a more detailed description of g-sensitivity and the equations for calculating the resulting phase noise in random and sine vibration environments.
John Vig Tutorial
[1] J.R. Vig, "Quartz Crystal Resonators and Oscillators – For Frequency Control and Timing Applications - A Tutorial", January 2004
Product | Package Size (mm) | Frequency Range | Temp Stability –40 to 85°C |
g-sensitivity | Shock | Vibration | |
MEMS | HT-MM900A |
7.0 x 5.0 x 0.90 5.0 x 3.2 x 0.75 3.2 x 2.5 x 0.75 2.5 x 2.0 x 0.75 2.0 x 1.6 x 0.75 |
1 to 137 MHz | 25ppm | 0.1ppb/g | ||
XO | PX-990 | 48.27 x 58.25 x 27 | 60 to 120 MHz | 25ppm | 0.5ppb/g | ||
PX-504 | 9.5 x 14.5 x 2.8 | 30 to 180 MHz | 25ppm | 0.3ppb/g | |||
VCXO | VX-504 | 9.5 x 14.5 x 2.8 | 30 to 160 MHz | 30ppm | 0.3ppb/g | ||
VX-990 | 48.27 x 58.25 x 27 | 60 to 120 MHz | 25ppm | 0.5ppb/g | |||
VCSO | VS-508 | 9 x 14 x 4.9 | 800 to 2900 MHz | 20ppm | 0.6ppb/g | ||
TCXO | TX-707 | 5 x 7 x 2.8 | 8 to 52 MHz | 1.0ppm | 0.1ppb/g | ||
TX-705 | 7.0 x 5.0 x 1.1 | 16 to 50 MHz | 1.0ppm | 0.1ppb/g | |||
TX-550 | 11 x 9 x 3.7 | 8 to 150 MHz | 1.0ppm | 0.2ppb/g | |||
TX-321 | 23 x 18 | 5 to 50 MHz | 1.0ppm | 0.2ppb/g | |||
OCXO | OX-080 | 37 x 37 x 13 | 8 to 15 MHz | 30ppb | 0.02ppb/g | ||
OX-043 | 52.07 x 52.07 x 26.67 | 8 to 15 MHz | 30ppb | 0.02ppb/g | |||
OX-046 | 52 x 52 x 20 | 50 to 250 MHz | 200ppb | 0.05ppb/g | |||
OX-407 | 14 x 20 x 11 | 10 to 50 MHz | 100ppb | 0.07ppb/g | |||
OX-405 | 13.21 x 20.83 x 10.16 | 80 to 120 MHz | 700ppb | 0.5ppb/g | |||
OX-990 | 48.27 x 58.25 | 60 to 120 MHz | 200ppb | 0.5 ppb/g | |||