VCXO and TCXO in application


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A VCXO (Voltage Controlled Crystal Oscillator) is a crystal oscillator whose frequency is determined by a crystal, but which can be adjusted or tuned by an external control voltage applied to the input. This type of XO (crystal oscillator) is commonly used in IC Clock generators.

Below is a diagram of a typical VCXO CLK generator.

VCXO

A TCXO (Temperature-Compensated Crystal Oscillator) is a high precision crystal oscillator with temperature-compensating circuitry built into it to maintain a more constant frequency across varying temperatures.

Frequency of TCXO

Sometimes a TCXO is used when the temperature vs. frequency stability of a traditional XO is insufficient over the temperature range expected of an application. TCXOs are widely used in cell phone or wireless applications. High-end TCXOs are also important components in telecom and other industries.