This article mainly introduces the causes and solutions for crystal oscillator stoppage. In today's electronic technology era, we cannot live without intelligent products, especially smartphones. In the fast-paced urban environment of mobile payment, the phone has become a necessity in our lives. However, we must know that a crystal oscillator that is smaller than a grain of rice determines the "life and death" of the entire circuit board. If it doesn't work, the entire system will be paralyzed. In the industry, it is compared to the heart of a circuit board.

The crystal oscillator is the "heartbeat" generator of various circuit boards. Choosing a good crystal oscillator can ensure the durability of the circuit board. However, the problem of crystal oscillator stoppage is difficult to avoid. The function of the crystal oscillator is to provide a reference frequency to various parts of components such as graphics cards, network cards, and motherboards. It is the most important component in the clock circuit. The crystal oscillator is like a ruler, and its unstable working frequency will cause the working frequency of related equipment to be unstable, which will easily cause problems. In practical applications, when encountering crystal oscillator stoppage, it is necessary to combine the actual situation and product specifications.

What are the characteristic phenomena if the crystal oscillator is damaged in the working circuit?

Crystal oscillator damage can be divided into two categories:

1. Complete stoppage: If the crystal oscillator stops, the phone may not be able to start up normally, just like the heart suddenly stops beating, and the circuits that use this crystal oscillator as the clock signal will stop working.

2. Instability: There are many reasons that cause instability, which may be due to crystal oscillator quality issues. More reasons are that the crystal oscillator parameters do not match the circuit parameters. For example, if the system requires an accuracy of 20ppm, but the crystal oscillator parameter is only 50ppm, or the matching capacitance requires 12PF, but the actual capacitance is only 9PF.

Solutions:

1. Complete damage: When completely damaged, it can be removed and compared with a normal same model integrated circuit to measure the positive and negative resistance of each pin to ground, and an abnormal resistance value can always be found in one or several pins.

2. Instability: Consult the crystal oscillator supplier, calculate the correct capacitance matching value to replace the crystal oscillator, or replace the external capacitor. Replace a crystal oscillator with appropriate accuracy. If the instability is caused by other problems, use anhydrous alcohol to cool the suspected integrated circuit. If the fault delay or no longer occurs, it can be judged. Usually, only by replacing a new integrated circuit can the problem be eliminated.

Points to note:

Because the crystal oscillator is prone to mechanical stress and thermal stress during cutting and soldering, and high soldering temperature and long action time will affect the crystal, it is easy to cause the crystal to be in a critical state and appear oscillation or stoppage. During soldering, when the solder wire penetrates through the small hole on the circuit board, causing the pin to be connected to the shell, or when the solder point of the pin on the base of the crystal is connected to the shell due to the manufacturing process, it will cause a short circuit, which will cause stoppage. When the crystal frequency drifts and exceeds the crystal frequency deviation range too much, and the center frequency of the crystal cannot be captured, it will cause the chip to fail to oscillate. Because the thickness of the chip itself is very thin, when the excitation power is too high, it will cause the internal quartz chip to break, causing stoppage. During the leak detection process, the crystal is prone to shell collision, that is, the chip is easy to collide with the shell during vibration, which will cause the crystal to oscillate or stop oscillating. During pressure sealing, the crystal requires vacuuming and nitrogen filling. If the pressure sealing is not good, that is, the sealing of the crystal is not good, it will show air leakage under the condition of alcohol pressurization, which is called double leakage, and it will also cause stoppage.

The above is the cause and solution of crystal oscillator stoppage, hoping to be helpful to everyone.