Selecting Components For Critical Industries May Require a Complete Drop-In Solution
When you start designing a project that requires clocking for key functionalities, a question arises about component selection: should you choose a crystal or a crystal oscillator for this particular application?
The answer depends on several factors specific to your project. In certain cases, crystal blanks are the preferred choice. Many engineers select crystals over oscillators in scenarios where performance specifications aren’t particularly strict, or when designing an oscillator is not prohibitive, either due to the simplicity of the project or the end-user’s expectations.
However, in cases requiring extremely tight stability over a wide temperature range, and it is critical that a clock delivers a high-quality, clean signal (e.g., quartz oscillators for medical technology), seek out a quartz crystal oscillator.
Comparing the Stability Of Crystals and Quartz Oscillators
Crystals experience performance degradation due to temperature shifts. When these temperature changes occur, the frequency of the crystal will start to drift. Enhancing the tolerance and stability of a crystal requires additional design optimizations, including the use of a chip with control functionality that improves the crystal’s signal.
However, oscillators aren’t characterized by tolerance and stability, but by stability alone. The stability specification for a quartz crystal oscillator expresses that within a given temperature range (e.g., -40 °C ~ 85 °C) frequency stability will be no worse than a certain number of parts per million (e.g., ±20ppm).
When ordering quartz oscillators for medical technology, automotive, Internet of Things, transportation, industrial or any other relevant industry, you get a drop-in solution with a clear understanding of its performance specifications.
Choosing a Crystal Instead Of a Quartz Oscillator
It is true that some applications that don’t require tight stability over temperature can use crystals as opposed to crystal oscillators. However, there are limitations to this approach:
- Conversion of an analog signal to digital: A crystal creates a sinusoidal wave when it emits its intended frequency. It requires additional design work to move it to the digital realm to meet the demands of today’s high-tech products. For industries that depend on digitization, including networking and communications, IoT and medical devices, quartz oscillators are already converted to a square wave signal and communicate by binary digits.
- Frequency range: Crystals limit frequency, which prevents their use in certain projects that require certain high frequency specifications.
- Introducing risk: In cases where an engineer chooses to design a discrete oscillator, risk is introduced, including cold solder joints, board capacitance issues affecting signal noise and accuracy, the need for tolerance stacking and more.
Crystal oscillators are the superior choice for many applications, when specifications and requirements demand a highly effective component. Additional benefits include:
- Lower current draw.
- Reassurance that it will function as intended every time.
- A pre-packaged solution, ready for a board.
Use Case: What Oscillators Achieve For MedTech Applications
The medtech industry is a strong example of an industry where quartz crystal oscillators are the ideal drop-in solution for projects that require frequency control.
Quartz oscillators used in medical devices provide several key functions, such as equipment control, monitoring patients, automating certain actions to free up medical personnel and communication between equipment.
Devices such as CAT scanners, MRI machines and other imaging technology cannot afford anything less than clean, stable, low-jitter, low-phase noise clocks. These are essential for acquiring a perfect, clear image that can be stored in a computer’s memory and recreated for a radiologist’s assessment.
An engineer in the design community will likely require quartz oscillators for medical technology that provide quality during each use in the field.
Choose Quartz Oscillators For Strong Performance Specifications
Although crystals have an exceptional role to play for frequency solutions across the industries that require them, crystal oscillators provide a convenient and high-quality solution for certain designs.
To determine the best clock for a project, work with a quartz oscillator manufacturer. These manufacturers can serve as an engineering resource throughout your project’s development, providing guidance, prototyping, tests, board placement suggestions, optimizations, recommendations and more.
Get started on an effective design now with these articles:
- Printed Circuit Board Design Considerations
- Introduction to Frequency Control
- Strong Engineering Principles For Crystal Oscillator Design
The following resources will help with component selections and key parameter determinations:
Crystals Versus Oscillators: Why Quartz Oscillators Are Preferred For High Performance was last modified: September 25th, 2024 by