What are the main types of crystal oscillators?

Crystal oscillator is the abbreviation of quartz crystal oscillator, which is a kind of precision electronic component made of special physical properties of quartz crystal. It is mainly used to generate oscillating signals with stable frequency, and is an important part of various electronic devices. According to different ways of classification, crystal oscillator can be divided into a variety of types.

Crystal oscillator has piezoelectric effect, that is, the crystal will be deformed after applying a voltage to both poles of the wafer, and in turn, if the wafer is deformed by an external force, a voltage will be generated by the metal sheet on both poles. If the wafer with the appropriate alternating voltage, the wafer will produce resonance (resonant frequency and quartz inclination angle, etc. have a relationship, and the frequency is certain). A crystal oscillator utilizes a crystal that converts electrical and mechanical energy into each other, and works in a state of resonance to provide stable, precise single-frequency oscillation. Under normal operating conditions, an ordinary crystal oscillator frequency absolute accuracy of up to 50 parts per million. Using this characteristic, crystal oscillator can provide more stable pulse, widely used in microchip clock circuit. The chip is mostly made of quartz semiconductor material, and the case is encapsulated with metal.

Classification by Frequency

• According to the different frequencies of the crystal oscillator, the crystal oscillator can be divided into low-frequency crystal oscillator, high-frequency crystal oscillator, microwave crystal oscillator and so on.

Low-frequency crystals: Crystals with frequencies below 1MHz are called low-frequency crystals. They are mainly used in clock signals, timers, sensors and other fields.

High-frequency crystals: Crystals with a frequency above 1MHz are called high-frequency crystals. They are mainly used in wireless communication, RF, Bluetooth, Wi-Fi and other fields.

Microwave crystals: Crystals with a frequency above 100MHz are called microwave crystals. They are mainly used in satellite communications, radar, radio and other fields

Classification by package form

• According to the different package forms of crystal oscillator, crystal oscillator can be divided into plug-in crystal oscillator and SMD crystal oscillator two kinds.

Plug-in crystal oscillator: plug-in crystal oscillator is inserted into the socket on the circuit board to use the pins. This kind of crystal is mainly used for old equipment or the need for frequent replacement.

SMD crystal oscillator: SMD crystal oscillator is to paste the crystal oscillator in the circuit board on the printed line for use. This kind of crystal oscillator has the advantages of small size, light weight, strong shock resistance, etc., is widely used in modern electronic equipment.

Classification by use

• According to the different uses of crystals, crystals can be divided into general-purpose crystals and special-purpose crystals.

General-purpose crystals: General-purpose crystals are general-purpose crystals that are applicable to various electronic devices. They are mainly used in computers, communication equipment, household appliances and other fields.

Special-purpose crystal: special-purpose crystals are special-purpose crystals that are applicable to specific electronic equipment. For example, high precision and low noise crystals are needed in medical equipment, and high frequency and high stability crystals are needed in satellite communication.

Classification by material

• According to the different materials of crystal oscillator, crystal oscillator can be divided into quartz crystal oscillator, ceramic crystal oscillator, crystal oscillator and so on.

Quartz crystal oscillator: quartz crystal oscillator is made of quartz crystal, because of its high stability and high precision and other advantages, it is widely used in a variety of electronic equipment.

Ceramic crystal: ceramic crystal is made of piezoelectric ceramic material, which has high frequency stability and low cost, and is widely used in TV sets, radios, remote controls and other products.

Crystal oscillator: crystal oscillator is made of crystal, it has the advantages of high stability and high precision, but the cost is higher, mainly used in high-end products.

Classification by shape

• According to the different shapes of crystal oscillator, crystal oscillator can be divided into cylindrical crystal oscillator, square chip crystal oscillator, tubular crystal oscillator and so on.

Cylindrical crystal oscillator: cylindrical crystal oscillator is the most common type of crystal oscillator, which has high stability and shock resistance, is widely used in computers, communication equipment, industrial control and other fields.

Square chip crystal: square chip crystal has a small size and weight, easy to integrate in the circuit board, is widely used in portable devices, smart home and other fields.

Tubular crystal oscillator: tubular crystal oscillator has high shock resistance and waterproof, is widely used in outdoor equipment, industrial control, automotive electronics and other fields.

In summary, there are many types of crystal oscillators, which can be divided into various types according to different classifications. When choosing crystal oscillator, you need to choose according to the actual application requirements and equipment characteristics. At the same time, in the use and maintenance of crystal oscillator, need to pay attention to its special physical properties, to ensure its normal operation and service life.