SNAA390 july   2023 LMK6C , LMK6D , LMK6H , LMK6P

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Test Standards and Test Setup
    1. 2.1 Test Standards
    2. 2.2 Test Setup in Vibration Lab
  6. 3Sinusoidal Vibration, Random Vibration, and Mechanical Shock Tests
    1. 3.1 Sinusoidal Vibration Test
      1. 3.1.1 Procedure for Sinusoidal Vibration Test
      2. 3.1.2 Results From Sinusoidal Vibration Test
    2. 3.2 Random Vibration Test
      1. 3.2.1 Procedure for Random Vibration Test
      2. 3.2.2 Results From Random Vibration Test
    3. 3.3 Mechanical Shock Test
      1. 3.3.1 Procedure for Mechanical Shock Test
      2. 3.3.2 Results From Mechanical Shock Test
  7. 4Comparison of BAW Oscillator Vibration Performance With Crystal Oscillator
    1. 4.1 Comparison Test Setup
    2. 4.2 Comparison Test Results
  8. 5Summary
  9. 6References

4.1 Comparison Test Setup

The MIL-STD-883H method 2026.B is selected for conducting a vibration comparison test. This test profile subjects the DUTs to an acceleration of 7.3-g rms. Figure 4-1 shows the vibration test setup created in the lab. The fixture is mounted on a vibration table, which is then subjected to an acceleration of a specific magnitude along the vertical axis. Three tests were performed on BAW oscillators and crystal oscillator devices. BAW oscillator shows better vibration immunity than its quartz counterparts.

GUID-20230628-SS0I-LB9D-KLN2-MJSPM0KDX5HX-low.svg Figure 4-1 Vibration Test Lab Setup Diagram

Random vibrations also increase oscillator phase noise. The test hardware generates random vibration over the specified frequency range, based on the power spectral density level in the MIL-STD-883H. Since the random vibration is spread over a range of frequencies, there is an overall increase in the phase noise of the output clock from the DUT rather than just spurs at specific frequency offsets which is generally observed in sinusoidal vibration tests. The integrated RMS phase jitter values are measured over an integration band from 12-kHz to 20-MHz range. Measurements are taken with and without the vibrations present and the RMS jitter difference between the two cases are calculated to determine the jitter induced by the vibration for each DUT.