• Ordinary Crystal Resonator (SPXO):

This is the most basic type of crystal resonator, with a simple structure and low cost. It is usually composed of a crystal and a peripheral circuit, and directly outputs a fixed frequency signal. Its frequency stability is relatively low, and it is generally suitable for occasions where the frequency accuracy is not too high, such as some simple consumer electronic products.

• Temperature Compensated Crystal Oscillator (TCXO):

Considering that temperature changes will affect the resonant frequency of the crystal, in order to improve the frequency stability, the temperature compensated crystal oscillator automatically adjusts the load capacitance of the crystal according to the change of ambient temperature through the built-in temperature compensation circuit, thereby compensating for the effect of temperature on the frequency. Its frequency stability is higher than that of SPXO, and it is often used in communication equipment, automotive electronics and other fields with high frequency accuracy requirements.

• Voltage Controlled Crystal Oscillator (VCXO):

The output frequency of this crystal oscillator can be adjusted by the input control voltage. By changing the size of the control voltage, the load capacitance or other related parameters of the crystal can be changed, thereby achieving fine-tuning of the output frequency. VCXO is often used in applications that require adjustable frequency, such as phase-locked loop (PLL) circuits, frequency synthesizers, etc.

• Oven-Controlled Crystal Oscillator (OCXO):

In order to obtain higher frequency stability, the oven-controlled crystal oscillator places the crystal in a constant temperature tank and uses a heating or cooling device to keep the crystal working at a constant temperature, thereby greatly reducing the impact of temperature on frequency. OCXO has extremely high frequency stability and is usually used in occasions with strict frequency accuracy requirements, such as aerospace, communication base stations, high-end test and measurement equipment, etc.