Random vibration induces phase noise at low offsets from the carrier frequency, as shown by the difference between the blue (no vibration) and red (with vibration) curves. Although the SiTime MEMS oscillator exhibits higher close-in phase noise when tested in a quiet environment, adding random vibration does not significantly increase the phase noise. In contrast, both SAW-based devices showed a dramatic increase in phase noise under random vibration. This level of degradation can be extremely detrimental to systems sensitive to close-in phase noise and shows how devices in real-world conditions may perform differently from datasheet specifications. While system designers can account for some level of phase noise, it is virtually impossible to protect against random vibrations and the resulting induced phase noise. SiTime products protect against the unknown by offering 12 to 20 x better performance compared to quartz-based oscillators.