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VCXO (Voltage-Controlled Crystal Oscillator) Product Introduction

Sep 09, 2026 Leave a message

Kavin Liu
Kavin Liu
Kavin Liu is a Senior Application Engineer at HCI. With nearly 30 years in the frequency control industry, he specializes in filters, resonators, and discriminators. His deep focus on these critical components helps engineers solve real-world signal.

VCXO (Voltage-Controlled Crystal Oscillator) Product Introduction

  • Product Overview

 The Voltage-Controlled Crystal Oscillator (VCXO) is a type of crystal oscillator that adjusts its output frequency by varying an external control voltage. Combining the high stability of a crystal oscillator with frequency adjustability , VCXOs are widely used in applications requiring precise frequency control.

VCXOs utilize a quartz crystal as the resonant element, offering a high Q-factor for stable frequency output. By introducing a control voltage, the VCXO can fine-tune its frequency within a small range, making it ideal for clock synchronization and signal adjustment.

  • Working Principle

 The core components of a VCXO include a quartz crystal and an oscillator circuit. When the control voltage changes, the capacitance of a varactor diode changes accordingly, altering the total capacitance of the oscillator circuit. This variation in capacitance causes a slight shift in the oscillation frequency. A higher control voltage results in greater frequency deviation. Although the tuning range is relatively narrow, it is sufficient for high-precision applications.

  • Key Features:

1.High Frequency Stability: VCXOs adopt quartz crystals to deliver outstanding frequency stability, ideal for precision clock and synchronization systems.

2.Frequency Adjustability: The output frequency can be fine-tuned within a specified range (typically a few ppm to tens of ppm) via control voltage adjustment.

3.Low Phase Noise: VCXOs feature low phase noise for high-frequency applications, providing high-quality signal output.

4,Excellent Temperature Stability: VCXOs retain high accuracy and stability over a wide temperature range (-40°C ~ +85°C), suitable for harsh operating environments.

  • Applications

1.Communication Systems: Widely deployed in wireless base stations, switches and fiber-optic communication gear to support clock synchronization and precise signal control.

2.Networking Equipment: Routers, switches and other network equipment use VCXOs to produce high-precision clock signals for reliable data transmission and synchronization.

3.Audio/Video Equipment: In high-end audio and video processing systems, VCXOs provide low-jitter clock signals to maintain synchronization and enhance playback quality.

4.Test & Measurement Instruments: Critical for frequency counters, signal generators and precision test instruments, enabling accurate frequency generation and tuning.

5.Satellite & Navigation Systems: High-precision tuning makes VCXOs ideal for GPS and satellite communication systems to achieve tight frequency control.

  • Product Specifications

Frequency Range: 1.25 MHz to 1500 MHz (model-dependent)

Frequency Tuning Range: ±50 ppm to ±100 ppm

Control Voltage Range: 0V to 5V (varies by design)

Operating Temperature Range: -40°C to +85°C

Phase Noise: -135 dBc/Hz @ 1kHz offset @ 50MHz

Supply Voltage: 1.8V / 2.5V / 3.3V / 5.0V

  • Conclusion

 With outstanding frequency stability and tunability, VCXOs play a vital role in modern communication, networking, audio/video, and test & measurement applications. Their flexible voltage tuning offers an effective solution for systems requiring frequency adjustment. Whether under extreme temperature conditions or high-precision synchronization scenarios, VCXOs deliver superior performance.

Hangjing offers VCXO products in various packages, with low phase noise and multiple output types (CMOS, LVDS, LVPECL).