TCXO is temperature compensated crystal oscillator. It is composed of a wide-range temperature compensation circuit and a high-precision crystal resonator to output a stable oscillation signal. High-precision TCXO, mainly used in network infrastructure.

A voltage-controlled crystal oscillator (VCXO) is usually used in the following situations: when the frequency needs to be adjusted in a small range, when the correct frequency or phase is important for the oscillator , Using different voltages as the control source of the oscillator, used to disperse the interference in a certain frequency range so that the frequency band is not too much affected. The typical frequency change of a voltage-controlled quartz oscillator is between tens of ppm. This is because a high quality factor (Quality Factor, or Q Factor) quartz oscillator will only produce a small frequency range shift.

The Oven Controlled Crystal Oscillator is a crystal oscillator that uses a constant temperature bath to keep the temperature of the quartz crystal resonator in the crystal oscillator constant, and reduces the change in the oscillator output frequency caused by the surrounding temperature change to a minimum. Applications in the military and aerospace fields: communications and navigation, identification of friend or foe, radar, guidance system, fuze, electronic warfare, sonar.