How to test the durability and reliability of crystal oscillators

     Crystal oscillators are important key components in modern electronic devices, such as clocks, frequency synthesizers, wireless communications and various signal processors, can not be separated from it. With the continuous development of this technology and the increasing application requirements, the durability and reliability of crystal oscillators have become a special concern in the design and manufacturing process. In order to make the crystal oscillator in practical application stable, long-term reliable operation, need some detection methods and means.

     Temperature cycle test. The effect of temperature change on the performance of crystal oscillators is not small. Doing this test allows the manufacturer to know how the crystal oscillator works at different temperatures. During the test, the oscillator is repeatedly heated and cooled in a certain temperature range, generally set at -40°C to +85°C. Each temperature state must be maintained for a while in order for the device to reach a thermally stable state. The key is to pay attention to frequency drift, phase noise, and changes in output amplitude, and to keep track of performance data for each temperature range.

     Under high temperature conditions, the frequency stability of the crystal oscillator may not be possible, and the output frequency will drift. At low temperatures, the operating frequency may also be unstable as the dielectric constant of the crystal changes. Therefore, through careful temperature testing, designers can provide very useful data, so that they can choose the right material and design structure, and improve the durability and reliability of the crystal oscillator. About the humidity test. The influence of humidity environment on crystal oscillator can not be underestimated. During manufacture and use, crystal oscillators may encounter high humidity conditions, especially in some industrial applications. Therefore, humidity testing is an important step to ensure its long-term reliability.

     The humidity test is generally carried out using the humid heat cycle method. The crystal oscillator is placed in a test chamber that simulates a high humidity environment, and the humidity is controlled to 85% and the temperature is 85°C for a period of time. When testing, the output frequency, output power and phase noise of the oscillator must be measured and recorded periodically. High humidity may cause corrosion inside the crystal or outside the package, which can affect oscillator performance. Through humidity testing, designers can know how durable the oscillator is in harsh environments, and can then choose a more suitable material or package design to enhance its resistance to moisture.

     There is also vibration testing, which is essential in the durability verification of crystal oscillators. Vibration can cause the components in the oscillator to move relative to each other, which can affect the stability of the frequency and signal.

     Vibration testing generally simulates mechanical vibration and shock in practical applications, and uses professional vibration testing equipment to put the crystal oscillator in a vibration environment of different frequencies and amplituaries for a period of time. At the same time, you have to keep an eye on parameters such as frequency drift, phase noise, and PLL performance. Through the vibration test, the weakness of the oscillator in the high vibration environment can be found, which can help the designer to optimize the structural design and improve the overall durability and stability.

     Next is the burn-in test, which is an important way to evaluate the long-term reliability of crystal oscillators. Through accelerated aging test, the service life of the device can be predicted in practical applications. Burn-in tests are typically performed at high temperatures, with crystal oscillators running at 70°C or higher for hundreds of hours. Over time, the oscillator may have frequency shifts, phase noise increases, and the output amplitude changes. Regular monitoring of these parameters can help designers understand the life characteristics of the equipment. Burn-in testing can not only help identify potential failure modes, but also provide designers with the basis for optimizing product design,to ensure that the performance will be maintained in the final practical application.

     Finally, electrical performance testing. This electrical performance test is the basis for ensuring stable operation of crystal oscillators under various operating conditions. These tests include startup time, stability time, frequency stability, and phase noise. In the electrical performance test, the time required for the crystal oscillator to reach a stable frequency must be noted, as well as the frequency output under different load conditions. These data can let the designer know how the oscillator is used in practice. In addition, frequency stability and phase noise are very important performance indicators of crystal oscillators, and detection with high-precision test equipment can help manufacturers understand the short - and long-term frequency stability of oscillators. This is very important to ensure the overall performance of the electronic device.

     By combining the above methods, the durability and reliability of the crystal oscillator can be effectively guaranteed, so that it can operate stably in a variety of application environments. These tests are not only to check the quality of the product, but also to provide a basis for future product development, to improve the competitiveness of the product to lay the foundation.