RF & Microwave, , Component Distributors Inc. (CDI) A Voltage-Controlled Crystal Oscillator (VCXO) is a crystal oscillator that has the ability to be tuned over a range of frequencies, often referred to as the "pulling range".  The VCXO is used as a building block for temperature-controlled crystal oscillators (TCXO) and also many Ovenized Crystal Oscillators (OCXO).

The oscillator frequency is changed by varying an analog voltage on the tuning pin of the device.  In most cases, the frequency changes as a linear function of voltage change.
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