Understanding the Differences Between TCXO and OCXO: A Comprehensive Guide

Understanding the Differences Between TCXO and OCXO: A Comprehensive Guide

When designing circuit boards, two types of crystal oscillators are commonly utilized: Oven Controlled Crystal Oscillators (OCXO) and Temperature Compensated Crystal Oscillators (TCXO). Knowing when to use each type is crucial for optimizing circuit performance. In this article, we will explore the key differences between TCXO and OCXO from three perspectives: definition, working principles, and measurement accuracy.

Definition

OCXO (Oven Controlled Crystal Oscillator) is a specialized oscillator that employs a constant temperature environment to stabilize the quartz crystal resonator. This minimizes frequency changes caused by temperature fluctuations. Typically, OCXOs utilize a differential series amplifier with a thermistor bridge for precise temperature control.

TCXO (Temperature Compensated Crystal Oscillator), on the other hand, uses electronic compensation to counteract frequency-temperature offsets in the crystal. By adjusting the load reactance of the crystal with temperature fluctuations, TCXOs achieve improved frequency stability, making them suitable for various applications.

Working Principles

OCXOs maintain a constant temperature to significantly reduce output frequency variations due to temperature changes. The oscillation frequency of a crystal is sensitive to temperature, so keeping it stable enhances its phase-frequency characteristics.

In contrast, TCXOs mitigate the frequency drift caused by ambient temperature changes through an integrated temperature compensation circuit. This circuit adjusts the load capacitance in the oscillating circuit, compensating for the resonator's frequency drift due to temperature variations.

Measurement Accuracy

When it comes to frequency stability, OCXOs typically outperform TCXOs by a significant margin. For instance, the frequency stability of a TCXO is generally around -7 dB, while OCXOs can achieve stability levels of -9 dB or better. This makes OCXOs the preferred choice for applications requiring high precision and stability.

Conclusion

In summary, understanding the differences between TCXO and OCXO is essential for selecting the right crystal oscillator for your circuit design. OCXOs offer superior frequency stability and precision, while TCXOs provide more flexibility in temperature compensation. By considering the specific needs of your application, you can optimize your circuits for better performance.

End-user ground receivers for satellite communications will be popularized in vehicles, ships and all corners of the world. In the field of satellite communications, KA and KU bands require up/down converters, and their key components need oscillators with high frequency and low phase noise. Xtalong Electronics' high frequency (High Frequency), low vibration sensitivity (Low G-sensitivity) temperature compensated crystal oscillators (TCXOs) and high-precision oven-controlled crystal oscillators (OCXOs) combine excellent frequency stability with very low phase noise, plus good anti-aging characteristics, making them ideal for ground station applications.

Features of Xtalong Electronics' high-precision temperature compensated crystal oscillators (TCXOs) and oven-controlled crystal oscillators (OCXOs)

1. Low power consumption

2. Low phase jitter

3. Low vibration sensitivity

4. Wide temperature range: -40°C ~+ 85°C

5. Maintain lock with communication satellite signals and provide accurate reference frequency source and time synchronization in harsh weather and environment

We offer the following TCXO models：

We offer the following OCXO models：

If you have any questions about model selection or customization needs, please feel free to contact our sales engineers.