Introduction

As devices such as car navigation systems and smartphones continue to become more sophisticated and compact, oscillators used as clock sources are required to deliver multifaceted performance, including high accuracy, high stability, and low power consumption.

In recent years, BAW (Bulk Acoustic Wave) oscillators, which utilize bulk vibrations of piezoelectric materials, have attracted attention due to their compact size, support for high-frequency operation, and stability in high-temperature environments.

However, in actual end-product design, there are still many applications in which crystal oscillators remain the optimal solution.
This article explains, using comparative data, the areas in which crystal oscillators offer advantages over BAW oscillators.

1. Reliability

Crystal oscillators adopt a hermetically sealed structure, enabling stable operation over long periods of time.

Thanks to this hermetic structure, they are highly resistant to changes in external environmental conditions such as temperature and humidity.
With an extremely long MTBF (Mean Time Between Failures), crystal oscillators are ideal not only for industrial and telecommunications equipment such as 5G base stations, but also for automotive applications that demand high reliability.

2. Startup Characteristics

Crystal oscillators are characterized by their ability to start oscillation quickly and stably after power is applied, with minimal startup delay even under varying temperature conditions. This makes them well suited for systems requiring immediate operation, such as automotive control systems and medical devices.

3. Current Consumption

Crystal oscillators operate with extremely low power consumption compared with other oscillation methods.
Under conditions of 3.3V supply voltage and frequency of 25MHz, BAW oscillators typically consume 35mA or more, whereas crystal oscillators can operate at approximately 2mA. This makes them ideal for IoT devices and battery-powered equipment, such as smartwatches, where low-power design is essential.

4. Phase Noise

Crystal oscillators feature exceptionally low phase noise, resulting in high signal purity and minimizing malfunctions or signal degradation caused by noise.
As a result, they help ensure stable communication quality and high measurement accuracy in applications such as optical transceivers and precision measurement equipment.

5. Shock Resistance（G-Sensitivity）

Crystal oscillators offer excellent vibration resistance, with G-sensitivity of 1 ppb/g or less. They can therefore be used reliably even in high-vibration environments such as automotive applications.

6. Low Failure Rate

With decades of experience in crystal device manufacturing, the company has achieved an extremely low failure rate of 0.3 FIT through advanced production processes and rigorous quality control.
Even during long-term use, performance degradation is minimal, contributing to reduced maintenance costs and improved overall system reliability.

Conclusion

While BAW oscillators offer advantages such as high-frequency operation and stability at elevated temperatures, crystal oscillators demonstrate superior overall balance for clock applications in end products. By correctly understanding and selecting the characteristics of crystal oscillators and BAW oscillators according to the application and required specifications, it is possible to enhance product performance and competitiveness.