The Working Principle of OCXO | Xtalong

OCXO 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 minimizes the change in the output frequency of the oscillator caused by changes in the ambient temperature. The OCXO is composed of a constant temperature bath control circuit and an oscillator circuit. Temperature control is usually achieved using a differential series amplifier formed by a thermistor "bridge".


The Advantages


Due to the constant temperature bath technology, the frequency temperature characteristic is the best among all types of crystal oscillators. Due to the precise circuit design, its short-term stability and phase noise are good.


The Disadvantages


Large power consumption, large volume, need about 5 minutes of heating time to work properly, etc.




1. Scientific research and measurement:

Atomic clocks, measuring equipment, telemetry, remote sensing, remote control;


2. Automotive field:

Engine control, stereo clock, sensors, driving computer, GPS application;


3. Military and aerospace fields:

Communication and navigation, IFF, radar, sensor, guidance system, fuze, electronic warfare, sonar;


4. Industrial fields:

Communications, telecommunications, mobile/cellular/portable terminals, aviation, navigation, navigation, instrumentation, computers, digital devices, displays, disk drives, modems, identification/authentication systems, sensors;


5. Consumption field:

Watches and clocks, cellular and cordless telephones, ordinary telephones, pagers, audio equipment, cable television systems and televisions, PCs, camcorders, amateur radio equipment, toys, medical devices and equipment.




1. The amplitude, tolerance, and polarity of the power supply voltage applied to the crystal oscillator are correct, and pay attention to the power supply ripple;


2. The power supply voltage should not exceed 10% of the working voltage to avoid burning components;


3. Please install the product in an anti-static environment;


4. Protect the constant temperature crystal oscillator during installation and transportation, and handle it with care to avoid product failure caused by high drop or collision;


5. The output load should match;


6. It is recommended to use manual welding, the welding temperature does not exceed 285 ° C, and the time does not exceed 5 seconds;


7. OCXO should be stored at -10℃+40℃, relative humidity not more than 80%, dry and ventilated, and the surrounding environment is free of acidic, alkaline and other harmful gases.