TCXO & VCTCXO

A temperature-compensated crystal oscillator (TCXO) helps maintain frequency stability as the operating temperature changes. A voltage-controlled temperature-compensated crystal oscillator (VCTCXO) adds a control-voltage input, allowing the output frequency to be adjusted within the device’s specified tuning range.

IQD’s TCXO and VCTCXO portfolio includes options designed for applications that need stable frequency control across a range of operating temperatures. Depending on the selected model, features may include low power consumption and fast warm-up.

How does a TCXO work?

A TCXO uses a temperature-sensitive compensation circuit in the oscillator to reduce frequency variation as the ambient temperature changes. This can provide improved frequency stability over temperature compared with an uncompensated crystal oscillator.

Some IQD TCXO models use an analog ASIC and higher-order temperature compensation. Performance and compensation characteristics vary by model; consult the datasheet for the specifications of each device.

What is the difference between a TCXO and a VCTCXO?

Both types compensate for temperature-related frequency changes. A VCTCXO also has a voltage-control input, which can be used to adjust the output frequency within the specified range.

• Choose a TCXO when the design needs improved frequency stability over temperature.
• Consider a VCTCXO when the design also needs voltage-based frequency adjustment.

The available tuning range and required control voltage depend on the selected part.

Applications for TCXOs and VCTCXOs

TCXOs and VCTCXOs are used in designs that need stable or adjustable frequency references, including:

• Wireless communications and telecommunications
• Internet of Things (IoT) devices
• GPS equipment
• SONET systems
• Fibre Channel systems

Selecting a TCXO or VCTCXO

Compare the specifications that matter to your design, including frequency stability over temperature, operating temperature range, supply voltage, power consumption and package. For a VCTCXO, also check the control-voltage range and frequency-tuning range. App Note | Specifying TCXO

Review the relevant datasheet to confirm that the selected model meets your requirements and contact IQD for help choosing a TCXO or VCTCXO for your application.