For reference oscillators, vibration and shock are common causes for increased phase noise and jitter, frequency shift and spikes, or even physical damages to the resonator and package. Compared to quartz crystals, the BAW resonator is more immune to vibration and shock due to the orders of magnitude smaller mass and higher frequency—that is force applied to the device from acceleration is much smaller due to smaller mass.

Figure 8-3 shows the CDC6Cx-Q1 BAW oscillator vibration performance. TI followed MIL-STD-883 Method 2026 Conditions C (10g) and Method 2007 Condition A (20g) for testing. In this test, the CDC6Cx-Q1 oscillator is mounted on an EVM and subjected to a 10g acceleration force, ranging from 50Hz to 2kHz in the x, y, and z-axis. Phase noise trace with spur due to vibration is captured using Keysight E5052B and frequency deviation is calculated from the spur power. Then the frequency deviation is converted to ppb by noting the carrier frequency and normalized to ppb/g. Finally, the RMS sum of ppb/g along all three axes is reported as the Vibration sensitivity in ppb/g. CDC6Cx-Q1 performance under vibration is approximately 2ppb/g while most quartz oscillators best case is 3ppb/g and worse can be above 10ppb/g.

Figure 8-3 Vibration Resilience vs Vibration Frequency at 25MHz, 25°C, Supply 1.8V - X-Axis

Figure 8-5 Vibration Resilience vs. Vibration Frequency at 25MHz, 25°C, Supply 1.8V - Z-Axis

Figure 8-4 Vibration Resilience vs. Vibration Frequency at 25MHz, 25°C, Supply 1.8V - Y-Axis

For the mechanical shock test, TI followed MIL-STD-883F Method 2002 Condition A (1500g) for testing. For more information on BAW technology mechanical robustness, see the Standalone BAW Oscillators Advantages Over Quartz Oscillators application note.

Figure 8-6 Pre and Post 1500g Mechanical Shock at 25MHz and 25°C, X-Axis

Figure 8-8 Pre and Post 1500g Mechanical Shock at 25MHz and 25°C, Y-Axis

Figure 8-10 Pre- and Post- 1500g Mechanical Shock at 25MHz and 25°C, Z-Axis

Figure 8-7 During 1500g Mechanical Shock at 25MHz and 25°C, X-Axis

Figure 8-9 During 1500g Mechanical Shock at 25MHz and 25°C, Y-Axis

Figure 8-11 During 1500g Mechanical Shock at 25MHz and 25°C, Z-Axis