Six Characteristics of Quartz Crystals to Consider For Optimal Timing Solution Performance
Because of its versatility, quartz has long been established as the best material to create accurate and durable timing solutions. Pieces of quartz are manipulated to meet the needs of many different systems. This versatility is a benefit for engineers, but at times adds confusion when they are looking to source specific components.
For a smoother process, focus on the following frequency control parameters to narrow options and identify the most relevant components for your system.
Frequency
Quartz naturally carries frequency, but it must be transformed from its natural state into the pieces – or crystals – that are utilized in timing solutions. Most quartz crystal frequencies fall between 32.768 kHz and 200 MHz. It is imperative that your quartz crystal oscillator matches the necessary frequency for your system. When designing circuits, remember that frequency is independent of other parameters.
Frequency Tolerance at Ambient Temperatures
Engineers look to avoid volatile and unexpected behavior from their quartz crystal oscillators, so they must be aware of the frequency tolerance of the crystals supporting their system. Frequency tolerance represents the maximum expected deviation from the rated crystal frequency during normal operation in ambient temperatures. This is a guaranteed figure from manufacturers that ensures the oscillating frequency of the quartz crystal stays within a certain range as long as the timing solution is utilized correctly. Select a timing solution with a maximum crystal frequency tolerance that safely falls within the acceptable range of your system.
Frequency Stability
Reputable manufacturers identify the quartz crystal frequency stability in two ways: Frequency deviation across the accepted operating temperature range and frequency deviation per change in temperature. These figures provide engineers with enough information to identify the timing solutions that are adequate for their systems. This allows them to anticipate the effects of temperature fluctuations on each potential timing solution and make the most informed choice.
Operating Temperature
One characteristic of quartz crystals that must always be considered is temperature dependency. All quartz crystal packages have temperature tolerances on their datasheet. Operating outside of guaranteed tolerances does not always lead to immediate problems, but it will lead to improper functioning over time. Be sure to source timing solutions that include crystals that are capable of withstanding all possible conditions.
Frequency Stability
Reputable manufacturers identify the quartz crystal frequency stability in two ways: frequency deviation across the accepted operating temperature range and frequency deviation per change in temperature. These figures provide engineers with enough information to identify the timing solutions that are adequate for their systems. Having the ability to anticipate the effects of temperature fluctuations on each potential timing solution allows engineers to make the most informed choices.
Load Capacitance
To maintain the most precise frequency within an oscillator, the correct load capacitance of the circuit must be considered. Load capacitance refers to the amount of external circuit capacitance in parallel with the quartz crystal itself. Quartz crystals are specifically manufactured to operate within a specified load capacitance range, so it is imperative to identify the needs of your system and marry them to the timing solution you are sourcing.
Package
While performance isn’t affected by the size of crystal packages, many circuit board designs fail because the size of each component was not considered. Package size is ultimately determined by frequency requirements. The lower the required frequency, the longer the crystal needs to be. Other factors that affect the size of crystal packages include:
- Hermetic Sealing: To reduce aging and achieve best performance, your quartz oscillator crystal packages will always be hermetically sealed. While hermetic sealing is necessary, it also increases package size and must be considered in the design of the circuit.
- Mounting Type: THT mounted quartz crystals are more widely used than their SMD counterparts, but are larger in size. Quartz oscillators themselves cannot be reduced in size, but a switch to an oscillator that utilizes an SMD mounted crystal package will save your design some space. Not all quartz crystals are available in every mounting form, so it is still important to account for space in the original design.
ECS Inc. Will Help You Identify What Quartz Crystal Oscillator Your System Needs
Whether you are looking to browse and compare potential components or work with a specialist to identify the needs of your system, ECS Inc. makes it easy to find the components you need.
Our Parametric Search and Search Inventory pages are perfect for narrowing down your options by the parameters identified above amongst others. The components we manufacture include real time clocks, resonators, filters and more.
For additional assistance, get in touch with an ECS Inc. sales representative to get the assistance you need or complete the contact form online to have one of our industry professionals contact you.
For purchasing, utilize the authorized distributors page on our website to locate trusted distributors near you.
Necessary Parameters to Understand When Selecting Quartz Crystal Products was last modified: February 22nd, 2023 by