Crystals

Suntsu Quartz Crystals are available in through-hole or surface-mount packaging with many sizes to choose from. Pick out a standard part number from the data sheets below or contact our sales team to request any custom parameters that you desire and we will design to your specific needs.

Quartz crystals have piezoelectric properties; they develop an electric potential upon the application of mechanical stress. They are the most common type of piezoelectric resonator used today.

SeriesImagePackageStability ToFrequencyReelKey FeatureDatasheet
SXT1041.2X1.0 CERAMIC SMD (4 PAD)±10ppm/±10ppm36.000MHz - 80.000MHz3KUltra-Miniature Package
SXT1141.6X1.2 CERAMIC SMD (4 PAD)±10ppm/±10ppm26.000MHz - 54.000MHz3KUltra-Miniature Package
SXT2142.0X1.6 CERAMIC SMD (4 PAD)±10ppm/±10ppm16.000MHz - 60.000MHz3KUltra-Miniature Package
SXT2242.5X2.0 CERAMIC SMD (4 PAD)±10ppm/±10ppm12.000MHz - 66.000MHz3KUltra-Miniature Package
SXT3243.2X2.5 CERAMIC SMD (4 PAD)±10ppm/±10ppm12.000MHz - 60.000MHz3KUltra-Miniature Package
SXT3G43.2x2.5 CERAMIC SMD (4 PAD GLASS)±10ppm/±10ppm10.000MHz - 60.000MHz3KMinature size, Glass seal, low height
SXT4244.0X2.5 CERAMIC SMD (4 PAD)±10ppm/±10ppm12.000MHz - 50.000MHz1KMiniature Package
SXT5345.0X3.2 CERAMIC SMD (4 PAD)±10ppm/±10ppm7.992MHz - 125.000MHz1KSmall Size
SXT5325.0X3.2 CERAMIC SMD (2 PAD)±10ppm/±10ppm8.000MHz - 100.000MHz1KSmall Size
SXT5G25.0X3.2 CERAMIC SMD (2 PAD GLASS)±10ppm/±10ppm8.000MHz - 54.000MHz1KSmall Size
SXT6346.0X3.5 CERAMIC SMD (4 PAD)±10ppm/±10ppm8.000MHz - 80.000MHz1KSmall Size
SXT6326.0X3.5 CERAMIC SMD (2 PAD)±10ppm/±10ppm7.000MHz - 100.000MHz1KSmall Size
SXT6G26.0X3.5 CERAMIC SMD (2 PAD GLASS)±10ppm/±10ppm8.000MHz - 80.000MHz1KLow Cost, Small Size
SXT7547.0X5.0 CERAMIC SMD (4 PAD)±10ppm/±10ppm6.000MHz - 125.000MHz1KWide Frequency Range
SXT8G28.0X4.5 CERAMIC SMD (2 PAD GLASS)±10ppm/±10ppm6.000MHz - 80.000MHz1KSmall Size
SXTHM2HC-49/US SMD (2 PAD)±10ppm/±10ppm3.000MHz - 90.000MHz1KLow Cost, Standard Package
SXTHM4HC-49/US SMD (4 PAD)±10ppm/±10ppm3.000MHz - 90.000MHz1KLow Cost, Plastic Alternative
SXTHS2HC-49/US±10ppm/±10ppm3.000MHz - 90.000MHzN/ALow Cost, Standard Package
SXTHU2HC-49/U±10ppm/±10ppm1.500MHz - 125.000MHzN/ALow Cost, Standard Package
SXTUM2UM-1±10ppm/±10ppm8.000MHz - 200.000MHzN/AWide Frequency Range
SCM13210.5X3.2 CYLINDER±20ppm/±30ppm3.579MHz - 90.000MHzN/AMiniature Package
SCM8328.3X3.2 CYLINDER±20ppm/±30ppm3.579MHz - 90.000MHzN/AMiniature Package
STF8328.3X3.2 CYLINDER±20ppm25.000kHz - 200.000kHzN/ALow Frequency
STF6226.2X2.1 CYLINDER±20ppm25.000kHz - 200.000kHzN/ALow Frequency
SWT6226.2X2.1 TUNING FORK±10ppm32.768kHzN/ALow Cost, Standard Package
SWT8328.3X3.2 TUNING FORK±20ppm32.768kHzN/ALow Cost, Standard Package
SWG6226.3X2.5 TUNING FORK GULLWING±20ppm32.768kHz2KLow Cost
SWG6J26.3X2.5 TUNING FORK GULLWING±20ppm32.768kHz2KMiniature Package.
SWS8348.0X3.8 PLASTIC SMD (4 PAD)±10ppm32.768kHz3KLow Cost, Standard Package
SWS6146.9X1.4 PLASTIC SMD (4 PAD)±20ppm32.768kHz3KMiniature Package.
SWS5124.9X1.8 CERAMIC SMD (2 PAD)±20ppm32.768kHz3KMiniature Package.
SWS4124.1X1.5 CERAMIC SMD (2 PAD)±20ppm32.768kHz3KMiniature Package.
SWS3123.2X1.5 CERAMIC SMD (2 PAD)±20ppm32.768kHz3KUltra-Miniature Package
SWS2122.0X1.2 CERAMIC SMD (2 PAD)±20ppm32.768kHz3KUltra-Miniature Package
SWS1121.6X1.0 CERAMIC SMD (2 PAD)±20ppm32.768kHz3KUltra-Miniature Package
SWS8328.0X3.7 CERAMIC SMD (2PAD)±20ppm30.000kHz - 2000.0kHz4KHigh shock and vibration resistant
SWS14410.4X4.06 PLASTIC SMD (4PAD)±10ppm/±20ppm32.7682KPlastic SMD 4 Pad Package
SXT14412.5X4.6 PLASTIC SMD (4PAD)±15ppm3.579MHz - 27MHz1KPlastic SMD 4 Pad Package

Quick Summary

Features Benefit Manufacturing Location(s) Monthly Capacity
• Low Cost
• Wide range of frequencies and packages
• Form factor down to 1.2 x 1.0mm
• Custom configurations available
• China
• Taiwan
• South Korea
• >20M units

What Is a Quartz Crystal?

A quartz crystal has electromechanical characteristics that allow it to operate in an electronic circuit as an oscillator with the addition of load capacitors and is an integral part of crystal electronics. It generates an electric signal with a specific frequency. It is valuable as an oscillator because the frequencies do not vary along with changes in temperature. Quartz crystal oscillators are important components in a long list of consumer devices, including smartphones, radios, medical devices, cars and communications transmitters.

Characteristics of Quartz Crystal Components

Crystal wafers are cut at specific angles that vibrate at precise frequencies when an electric field is applied. What makes components of electronic crystals so unique and popular for use in electronic devices is that they are generally very stable across a broad range of temperature changes. Their resistance to changes in environmental factors makes them reliable in terms of maintaining their precise frequencies.

Roles of Quartz Crystal Components

The most important functions of quartz crystal components are maintaining stable frequencies and generating steady reference signals. They are incorporated into electronic devices that rely on a stable frequency to be able to send and receive necessary information. The steady reference signals produced by quartz crystal components help synchronize the various parts of electronic devices, such as clocks, that rely on precise timing to function accurately.

Types of Crystals

The AT-cut quartz crystal is very popular and is typically found in electronic devices that run on a frequency range of 1MHz to approximately 200MHz. The BT-cut quartz crystal is used at slightly higher frequencies. The SC-cut quartz crystal was originally developed for use in crystal ovens as it is particularly resistant to premature aging and effective at noise minimization while operating.

The Many Applications of Quartz Crystal Units

Quartz crystal units are so prevalent in electronics because of their role in producing stable frequencies and steady reference signals. Quartz crystal oscillators operate as part of an integrated circuit. They are frequently used in radio transmitters and receivers as well as any electronic device that depends on a clock signal.

Quartz Crystals vs. Ceramic Resonators

Quartz crystals and ceramic resonators operate in similar ways because they both vibrate when exposed to AC signals, but they have different characteristics. Quartz crystals maintain accurate frequency stability without requiring significant power. On the other hand, ceramic resonators are more frequently found in microprocessor components where slight fluctuations in frequency are acceptable. Essentially, quartz crystals are preferred over ceramic resonators for use in electronic devices that are subject to temperature variations and environmental changes and require maintaining an extremely accurate frequency.

Quartz Crystal Resonance Modes

A quartz crystal can operate in both series and parallel resonance. The parallel resonance is higher by just several kilohertz than the series resonance. A quartz crystal under 30 MHz operates as an inductive reactance as it is between series and parallel resonance. A quartz crystal above 30 MHz and up to higher than 200 MHz is more likely to operate at series resonance.

Spurious Frequencies With Quartz Crystals

Spurious frequencies are also referred to as “unwanted responses” and may be generated when a quartz crystal is vibrated, which can modulate the resonant frequency slightly. An SC-cut crystal will likely be less vulnerable to spurious frequencies from external vibrations. In addition, spurious frequencies may also be found in quartz crystals that are operating at series resonance or being pulled away from the primary mode. This typically involves the work of a series inductor or capacitor. Also, significant temperature changes in conjunction with the series resonance of the quartz crystal can result in spurious frequencies.

Commonly Used Quartz Crystal Frequencies

The range of frequencies available for quartz crystals that are made for oscillation is quite broad. They range from just several kilohertz to up to hundreds of megahertz. Generally, the most commonly used crystal resonance frequency is from 20MHz to 40MHz especially for wireless communication.

Quartz Crystal Structures and Materials

Quartz Crystal

When it comes to oscillator for crystal electronics, quartz crystal is the most commonly found material. Quartz Crystal is manufactured to maintain precise frequencies when used in operating an electronic device.

Production

Quartz Crystal is grown and manufactured for specific purposes in electronic devices. For example, the AT-cut crystals are made specifically for oscillator devices. High-quality crystal quartz is used in premium electronic devices and contains minimal levels of defects or impurities. They are manufactured artificially in strictly controlled environments by starting with a seed crystal at a temperature of about 350°C. At a pressure of approximately 1,000 atmospheres, it generally takes between 45 to 90 days for a synthetic quartz crystal to form in a growing furnace.

Types

There are left-handed and right-handed quartz crystals. While their optical rotations are certainly different, they share many of the same characteristics. Depending on the cut edge of the crystal, both left-handed and right-handed quartz crystals can be used in crystal oscillators. However, right-handed quartz crystals are generally more common in manufacturing.

How Is Frequency Stability Determined?

The frequency stability of a quartz crystal is essentially set in stone upon its physical shape and the precise angle of the final cut of the quartz crystal. Along those lines, the stability of the crystal frequency is based on the crystal’s Q factor.

Temperature

The angle of the cut of the quartz crystal establishes the crystal’s sensitivity to changes in temperature. Changes in temperature exposure for the crystal can alter the crystal’s operating frequency. Some crystals feature temperature-dependent cuts in order to reduce the crystal’s temperature or frequency dependence.

Mechanical Stress

A quartz crystal’s frequency is subject to variations as a result of mechanical stress. They can disrupt the crystal during the manufacture and operating processes, including pressure within the crystal enclosure and movement of electrodes. An SC-cut quartz crystal is typically less reactive to mechanical stresses.

What Happens When Quartz Crystals Age?

When quartz crystals age, their resonant frequency moves slightly. Even though the resulting variations in frequency levels may seem relatively minor, they can have major consequences for the proper functioning of the electronic device in which they are used. The quartz crystals used in Suntsu’s high-quality products reflect strictly controlled manufacturing environments and the chemical etching process that minimizes the entrance of contaminants. Similarly, the circuit design of the device in which the quartz crystal will be used is made specifically to keep low drive levels and slow the crystal aging process in turn.

Mechanical Damage

Shock-induced changes to the quartz crystal’s environment can result in significant and lasting mechanical damage to the crystal itself, which will ultimately accelerate the aging process. It may first present as an immediate change to the frequency of the crystal oscillator. If the surface of the crystal is smooth and free from imperfections, then it is more likely to resist external shocks. The process of chemically polishing the surface of the quartz crystal can increase its resistance to external shocks and other mechanical damage.

Frequency Fluctuations

There are a variety of reasons why a quartz crystal may experience changes in its frequency, which are also known as frequency fluctuations. Temperature changes, vibrations, mechanical shocks, orientation changes and thermal noise are some of the common causes of frequency variations in quartz crystals. Changes in the acceleration and vibrations tend to overpower the impact of any other variations in noise levels that could induce frequency changes in a quartz crystal.

Quartz Crystal Cuts: AT-Cut vs. SC-Cut

AT-cut and SC-cut quartz crystals feature distinct temperature stability curves. Primarily, the AT-cut quartz crystal is the superior choice for a broad range of temperatures. This helps the AT-cut crystal maintain its status as one of the most commonly used types of crystals in electronic devices that rely on crystal oscillators beginning at 1MHz. The upper limit of 200 MHz for many commercial quartz crystal oscillators continues to expand with cutting-edge innovations in the manufacturing and processing of the quartz crystals. On the other hand, the SC-cut quartz crystal, also known as the “stress compensated” quartz crystal, was manufactured mainly for use in crystal ovens due to its reduced sensitivity to changes in thermal or mechanical stress. In addition, the phase noise and relatively slower aging profile of SC-cut crystals make them ideal for use in crystal ovens.

Quartz Crystal Oscillators

Quartz crystal oscillators are a widely used type of electronic oscillator circuit that relies on the mechanical resonance from the vibrations of a quartz crystal. The specific frequencies that are produced from a quartz crystal oscillator are used in all types of devices that run on clock time as well as for radio transmitters and receivers. Voltage is applied to an electrode to generate an electric field to distort the quartz crystal. The specific frequency produced by the quartz crystal determines how it will ultimately be used in an electronic device. When a quartz crystal is manufactured for an oscillator, the specific frequency can vary from only a few kilohertz to several hundreds of megahertz.

Quartz Crystal Impedance Against Frequency

The impedance of a crystal is generally measured in terms of its reactance against frequency or resistance against frequency. The slope of the quartz crystal impedance changes according to changes in the frequency of the crystal.

Quartz Crystal Reactance Against Frequency

The reactance of the quartz crystal will vary along with changes in the quartz crystal’s frequency. An increase in the frequency of the quartz crystal results in a similar increase in inductive reactance. However, an increase in the frequency of the quartz crystal also means a reduction in the capacitive reactance. Reactance is generally like resistance as smaller currents from the same level of voltage applied to the quartz crystal result from larger reactance.

Series Resonant Frequency

When there is low impedance to the flow at a particular frequency, then series resonance can occur. Series resonance is achieved when the inductive reactance within a circuit is at the same level as the circuit’s capacitive reactance. Series resonant is useful for magnifying the signal voltage from a signal transmitter as well as the current for a specific frequency.

Parallel Resonant Frequency

When there is high impedance to the flow at a particular frequency, then parallel resonance can occur. A parallel resonant circuit is more frequently used in electronic devices than a series resonant circuit. In the parallel resonance condition, a circuit uses the minimum current because the reactive part of the current has been suppressed.

Crystal Oscillator Circuits

A crystal oscillator circuit uses the voltage supplied from the crystal quartz resonator. The crystal oscillator circuit works by amplifying that voltage and then sending it back to the crystal quartz resonator. When the quartz crystal expands and contracts repeatedly, a specific resonant frequency is generated. The particular resonant frequency is based on the size and the cut of the quartz crystal used in the crystal oscillator circuit. Oscillation within the particular device is sustained by the matching of the resonant frequencies produced to those lost by the crystal oscillator circuit.

Microprocessor Crystal Quartz Clocks

Almost every one of the microprocessors used in the production of electric devices is made with a quartz crystal oscillator. The quartz crystal oscillator works as the frequency-setting and maintaining component of the microprocessor and is highly regarded for its strong characteristics of frequency accuracy and stability compared to other microprocessor options. Microprocessor crystal quartz clocks are made up of a quartz crystal and two ceramic capacitors with values between 15 to 33pF.

Frequently Asked Questions

Quartz crystals have been an extremely popular component of circuits based on their reliability and stability in setting and maintaining proper frequencies. The failure of a device to maintain its precise frequency when operating can mean that it will not function properly at all. This is why quartz crystals are such an essential element for top-quality design and manufacture of a wide variety of popular electronic devices. Quartz crystals were first used in circuits based on their relationship and exploitation of the piezoelectric effect starting at the beginning of the 20th century. Although the piezoelectric effect was studied in the scientific community years before then, quartz crystals were not yet manufactured and processed specifically for their frequency-setting capabilities before then because the electronic devices, such as radios, for which they are used were not yet invented.

When it comes to determining a specific frequency for use in an electronic device or radio signal transmitter, the quartz crystals are absolutely essential. Quartz crystals are one of the most widely used components in electronic system clocks and for setting the primary frequency in radio signal transmitters and receivers. With the incorporation of a main quartz crystal frequency in a radio transmitter and receiver, the remaining radio channels could be developed and set using frequency synthesizers. The innovation of using quartz crystals for radio transmitters and the invention of frequency synthesizers revolutionized the process of tuning radios with precision settings and improved frequency stability.

The quartz crystal blank as well as the quartz crystal are both two of the most important components within an electronic device, which is why they are studied and manufactured to the most precise standards.

Generating specific frequencies at or below the range of the quartz crystal blank is accomplished by the usage of a divider or a phase-locked loop (PLL). If you want to create a frequency below the standard range for a quartz crystal, then either a divider can be used for the downward conversion. Alternatively, if you want to generate a frequency above the standard range for a quartz crystal blank, then a PLL can facilitate the conversion. Another more intensive option for altering the fundamental resonance of the crystal is to use a crystal filter for the many harmonic overtones that quartz crystals and their operators are designed to operate with.

As far as quartz crystal frequencies go, there is a wide variety of frequencies that can be produced by quartz crystals for use in operating an electronic device or communications signal transmitter or receiver. However, there are certainly standard quartz crystal frequencies that are commonly generated and maintained in the operation of commonly used electronic devices. Many quartz crystals are manufactured specifically for standard frequencies, such as 4, 10, 20, 25, 26, 30MHz and 32MHz. Electronic devices that run on digital clocks typically run on quartz crystals that generate a frequency of 32.768 kHz.

The quartz crystal blank is also referred to as a crystal slab and is considered the core of the electronic circuit. It functions within the quartz crystal unit as a resonating element. The proper performance of the quartz crystal blank is vital for the effective functioning of the electronic device itself, which is why its assembly requires quality materials and attention to detail. The quartz crystal blank is attached to the circuit itself by using flat electrodes on the flat faces. Once the electrodes are assembled with the quartz crystal blank, it is usually enclosed in metal to minimize the potential for electrical interference.

The size of the quartz crystal blank is determined by the package size of the quartz crystal. In terms of the most commonly used quartz crystal blank, it is generally only a few millimeters squared. They are almost always extremely thin so that they can be effectively incorporated into the quartz crystal unit for the operation of an electronic device. High-quality electronic devices include a quartz crystal blank that is manufactured and cut to the precise measurements that coincide accurately with the dimensions of the complete quartz crystal unit.

The process of adjusting the quartz crystal blank to the specific resonant frequency at which it is expected to operate is similar to the way that you would polish a glass lens. This involves a finely-tuned combination of polishing and grinding. While the act of adjusting the quartz crystal blank to its precise resonant frequency was originally performed by skilled craftsmen relying on their own handiwork, it is now automated to reduce the possibility of human error and improve the accuracy of the final result. Precise measurements and cutting-edge automation technology used in the grinding and polishing of the quartz crystal blank mean that the final blank to be inserted into the complete quartz crystal unit is made entirely to the required specifications.

Both crystals and oscillators are used in a variety of electrical devices and processors. Crystals vibrate upon application of an AC signal and must be specifically calibrated for use within a particular crystal oscillator. The major difference between quartz crystal and an oscillator is that an oscillator includes quartz crystal and two additional capacitors. In other words, the crystal is one of the parts that make up the complete crystal oscillator. A crystal oscillator also includes an amplifier that generates the energy to perpetuate the oscillation.

Quartz crystal clocks are found in a long list of popular consumer electronic devices and rely on the performance-grade manufacturing and assembly of quartz crystal components to run properly over the lifetime of the device. The higher the specific frequency of the quartz crystal, the smaller in size that the quartz crystal blank must be cut and manufactured for insertion into the quartz crystal clock.

Testing for quartz crystals involves the use of a digital multimeter, which is connected to the crystal oscillator within the electronic device. The measurement probes of the crystal oscillator are connected to the digital multimeter before turning the digital multimeter on and selecting the frequency function. The reading on the digital multimeter should match the precise frequency setting established for the crystal oscillator if the oscillator is working as intended.

An RTC crystal maintains the desired frequency setting and timing function of a crystal clock by keeping track of the oscillator’s cycles. This allows the RTC crystal to sense the 50/60 Hz ripple of the device’s main power supply from the crystal power cell. In this sense, the RTC crystal functions similar to a PLL. Even when an RTC crystal loses its external reference point, it can still maintain its proper operations by relying on its internal clock reference and running with the internal oscillator.

The frequency 32.768 kHz is ideal for most personal digital watches and quartz crystal clocks. The main reason for this frequency selection is that a flip-flop chain can be conveniently used to divide down that precise frequency to exactly one pulse per second. This pulse rate is precisely the way that crystal quartz clocks measure and mark time in digital devices, such as digital watches.

A quartz crystal oscillator works in an electronic device due to the mechanical resonance of its vibrating quartz crystal based on the piezoelectric effect. The quartz crystal is the source of the piezoelectric effect based on the application of mechanical pressure to the surface of the quartz crystal, which produces a proportional voltage. In turn, this produces distortion within the quartz crystal.

Crystal devices are essential components of many common consumer electronic devices, such as smartphones and automotive infotainment systems. Quartz crystal units and quartz crystal oscillators are considered key components of electronic devices based on their desirable properties of maintaining stable frequencies and steady signals. They are particularly resistant to changes in temperature and other external environmental factors, which makes quartz crystal an important material for use in precision-grade electronic devices.

An oscillator that incorporates a crystal operates on the general principle of the piezoelectric effect. This refers to the phenomenon that occurs when a generic crystal is exposed directly to voltage from an electric field, which results in the dimensions of the crystal changing in a reversible direction. In addition, when a generic crystal is stressed, it generates a modest voltage itself. The piezoelectric effect is found in crystals beyond the specific form of quartz crystal. The quartz crystal oscillator works off of the inverse piezoelectric effect because it capitalizes on the mechanical resonance from the vibrations of the quartz crystal to produce an electrical signal at the desired frequency.

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