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Crystal concept

Quartz crystal oscillator, quartz resonator is referred to as crystal oscillator, which is made of quartz crystal sheet with piezoelectric effect.

When the quartz crystal sheet is subjected to an external alternating electric field, it will produce mechanical vibration. When the frequency of the alternating electric field is the same as the natural frequency of the quartz crystal, the vibration will become very strong, which is the response of the crystal resonance characteristics.

Using this characteristic, it is possible to replace LC (coil and capacitor) resonant circuits, filters, etc. with quartz resonators. Because quartz resonators have the advantages of small size, light weight, high reliability, and high frequency stability, they are used in household appliances and communication equipment.

Crystal classification

1. According to the production material, it is divided into quartz crystal oscillator and ceramic crystal oscillator.

Quartz Crystal Oscillator Definition

It is a resonant device made by the piezoelectric effect of quartz crystal (crystal of silicon dioxide). Rectangular or circular, etc.), coat silver layers on its two corresponding surfaces as electrodes, solder a lead on each electrode and connect it to the pin, plus the package shell to form a quartz crystal resonator , referred to as quartz crystal or crystal, crystal oscillator. Its products are generally packaged in metal shells, but also in glass shells, ceramics or plastics.

Classification of quartz crystal oscillators

(1) Non-temperature compensated crystal oscillator.

(2) Temperature Compensated Crystal Oscillator (TCXO).

(3) Voltage Controlled Crystal Oscillator (VCXO).

(4) Oven Controlled Crystal Oscillator (OCXO).

(5) Digital/μp compensated crystal oscillator (DCXO/MCXO).

(6)......

Among them, the non-temperature-compensated crystal oscillator is the simplest one. In the Japanese Industrial Standard (JIS), it is called a standard packaged crystal oscillator (SPXO).

Applications of Quartz Crystal Oscillators

(1) Quartz clocks are the biggest advantages of accurate running time, low power consumption and durability. Whether it is an old-fashioned quartz clock or a new multi-functional quartz clock, the quartz crystal oscillator is the core circuit, and its frequency accuracy determines the travel time accuracy of the electronic clock.

(2) With the development of TV technology, 500kHz or 503kHz crystal oscillators are used in color TVs as the oscillation source of the line and field circuits. The line frequency of 15625Hz is obtained by dividing the frequency by 1/3, which has great stability and reliability. to improve. The crystal oscillator is cheap and easy to replace.

(3) In communication system products, the value of quartz crystal oscillators has been more widely reflected, and it has also been developed faster. Many high-performance quartz crystal oscillators are mainly used in communication networks, wireless data transmission, high-speed digital data transmission, etc.

Ceramic crystal oscillator definition

It refers to a crystal oscillator packaged in a ceramic shell, which is less accurate than a quartz crystal oscillator, but has a lower cost, and is mainly used in electronic products that do not require high frequency accuracy.

2. According to the shape, it is divided into rectangular crystal oscillator, cylindrical crystal oscillator and oval crystal oscillator.

3. According to the package form, it is divided into glass vacuum sealed crystal oscillator, metal shell packaged crystal oscillator, ceramic packaged crystal oscillator, and plastic shell packaged crystal oscillator.

4. According to the package form, it can also be divided into patch and in-line.

5. According to the resonant frequency accuracy, it is divided into high-precision, medium-precision and ordinary crystal oscillators.

6. According to the application characteristics, it is divided into series resonance type crystal oscillator and parallel resonance type crystal oscillator.

Series resonant crystal oscillator

①The load capacitance of the series resonant crystal oscillator is small, and it belongs to the low load capacitance crystal oscillator;

②The series resonant crystal oscillator can only be used under the condition of low load capacitance, or can only be used in the series oscillator circuit;

③ Since the crystal oscillator is connected in series with the load capacitance to form resonance, the oscillation frequency can be adjusted to the standard value accurately by fine-tuning the load capacitance.

Parallel resonant crystal oscillator

①The load capacitance of the parallel resonant crystal oscillator is very large, and it belongs to the high load capacitance type crystal oscillator;

②The parallel resonant crystal oscillator can only be used under the condition of high load capacitance, or can only be used in the parallel oscillator circuit;

③ The oscillation frequency of the parallel oscillator circuit is not adjustable, which requires the parallel resonant crystal oscillator to have higher precision, more stable performance and more precise resonance frequency.

7. According to the function and realization technology of crystal oscillator, it is divided into temperature compensated crystal oscillator (TCXO), voltage controlled crystal oscillator (VCXO), ordinary crystal oscillator (SPXO), and constant temperature crystal oscillator (OCXO).

Temperature Compensated Crystal Oscillator (TCXO)

It is a quartz crystal oscillator that reduces the amount of oscillation frequency variation due to ambient temperature changes by adding a temperature compensation circuit. There are mainly two types of compensation methods for the frequency temperature drift of quartz crystal oscillators: direct compensation and indirect compensation. Application: Test equipment. Frequency range: 1MHz-160MHz.

Voltage Controlled Crystal Oscillator (VCXO)

It is a quartz crystal oscillator whose oscillation frequency is variable or modulated by applying an external control voltage. In a typical VCXO, the frequency of the crystal oscillator is "pulled" by changing the capacitance of the varactor diode, usually by tuning the voltage. Main application: frequency shift repeater, test equipment, cellular base station. Frequency range: 1MHz-200MHz.

Oven Controlled Crystal Oscillator (OCXO)

It is a crystal oscillator that minimizes the change in the output frequency of the oscillator caused by changes in ambient temperature by keeping the temperature of the crystal oscillator or quartz crystal resonator constant by using an oven controlled chamber. OCXO is mainly used in equipment and instruments such as mobile communication base stations, national defense, navigation, frequency counters, spectrum and network analyzers. Frequency range: 1MHz-160 MHz.

8. According to the composition of the crystal oscillator circuit, it is divided into active crystal oscillator and passive crystal oscillator.

Passive crystal oscillator is crystal

Passive crystal oscillators need the help of a clock circuit to generate an oscillating signal, and cannot oscillate by themselves, so the term "passive crystal oscillator" is not accurate; passive crystal oscillators have only two pins, and there is no so-called positive and negative poles.

Active crystal oscillator is called oscillator (oscillator)

The active crystal oscillator is a complete resonant oscillator. The active crystal oscillator needs to be connected to the power supply to work. Generally, there are four pins, including two power input pins, which are divided into positive and negative poles.

9. Crystal oscillators in electronic clocks are divided into low-frequency tuning fork type and high-frequency circular sheet type according to the shape of the quartz wafer.

Processing flow chart

Summarized into 10 major steps: 1. Orientation. 2. Coating. 3. Dispensing. 4, fine-tuning. 5. Appearance printing. 6. Test. 7. Aging. 8. Sealing and welding. 9. Packaging. 10. Warehousing.

10 Steps Explained

related terms

1. Nominal frequency

A crystal oscillator is a frequency component, and each crystal oscillator has its own frequency. The frequency is usually marked on the product shell, and the imported crystal oscillator brand will be replaced by the brand's logo or letters.

2. Temperature frequency difference

Under specified conditions, the allowable deviation of the operating frequency relative to the reference temperature (25±2℃) within the operating temperature range.

3. Working frequency

The frequency produced by the crystal together with the working circuit.

4. Adjust the frequency difference

Under specified conditions, the allowable deviation of the operating frequency relative to the nominal frequency at the reference temperature (25±2℃).

5. Load resonance frequency (fL)

Under specified conditions, the crystal is connected in series or in parallel with a load capacitor, and its combined impedance appears resistive at one of two frequencies. With a load capacitor in series, the load resonant frequency is the lower of the two frequencies One, when the load capacitance is in parallel, is the higher of the two frequencies.

6. Dynamic resistance

Equivalent resistance at series resonant frequency. It is represented by R1.

7. Load resonance resistance

Equivalent resistance presented at the load resonant frequency. Represented by RL. RL=R1(1+C0/CL)2

8. Excitation level

Characteristic value of the power consumed by the crystal during operation. The optional values of excitation level are: 2mW, 1mW, 0.5mW, 0.2mW, 0.1mW, 50μW, 20μW, 10μW, 1μW, 0.1μW, etc.

9. Fundamental frequency

The vibration frequency at the lowest order of the vibration mode.

10. Aging rate

The relative change in crystal operating frequency allowed over time under specified conditions. When measured in years, it is called the annual aging rate.

11. Electrostatic capacitance

The capacitor connected in parallel with the series arm in the equivalent circuit, also called the parallel capacitor, is usually represented by C0.

12. Load capacitance

Together with the crystal, it determines the effective external capacitance of the load resonant frequency fL, usually expressed by CL. The load capacitance series are: 8PF, 12PF, 15PF, 20PF, 30PF, 50PF, 100P. Recommended values should be selected whenever possible: 10PF, 20PF, 30PF, 50PF, 100PF. The commonly used load capacitors for 32.768K crystal oscillators are 12.5PF, 6PF, 9PF, etc.

13. Overtones: Mechanical Harmonics of Crystal Vibration

The ratio of overtone frequency to fundamental frequency is close to integer multiples but not integer multiples, which is its main difference from electrical harmonics. Overtone vibration has 3 overtones, 5 overtones, 7 overtones, 9 overtones and so on.

Five elements of selection

1. Output frequency

The most fundamental property of any oscillator is the frequency it generates. By definition, an oscillator is a device that accepts an input voltage (usually a DC voltage) and produces a repetitive AC output at a certain frequency. The required frequency is determined by the type of system and how the oscillator is used.

Some applications require low frequency crystals in the kHz range. A common example is a 32.768 kHz hand (clock) watch crystal. But most current applications require higher frequency crystals, ranging from less than 10MHz to greater than 100MHz.

2. Frequency stability and temperature range

The required frequency stability is determined by the system requirements. The stability of an oscillator can be simply expressed as the change in frequency due to some cause divided by the center frequency. (ie: stability = frequency change ÷ center frequency)

3. Input voltage and power

Crystal oscillators of any type can generally be designed to operate with the DC input supply voltage already present in the system. In digital systems, it is often desirable to drive the crystal oscillator with a voltage that matches the voltage used by the logic devices in the system that the oscillator will drive so that the logic levels are directly compatible. +3.3V or +5V are typical inputs for these digital units. Other devices with higher power outputs can use higher voltages, such as +12V or +15V. Another consideration is the amount of current required to power the device. An XO or TCXO may only require a few mA, so its power consumption can be less than 0.01W in low voltage systems. On the other hand, some OCXOs can require 5W or 6W at power up.

4. Output waveform

The output waveform is then chosen to match the load the oscillator will drive in the system. One of the most common outputs is CMOS - inputs that drive logic levels. The CMOS output will be a square wave swinging between ground and the Vdd rail of the system. For higher frequencies above about 100MHz, differential square waves are typically used. These oscillators have two outputs 180° out of phase, fast rise and fall times, and very little jitter. The most common types are LVPECL and LVDS. If an oscillator is used to drive an RF component such as a mixer or other device with a 50Ω input impedance, a sine wave output of a certain power level is usually specified. The resulting output power is typically between 0dBm and +13dBm (1mW to 20mW), although higher powers can be output if desired.

5. Package size and shape

Crystal packaging requirements will vary widely based on oscillator type and size. Simple clock oscillators and some TCXOs can be housed in packages as small as 1.2 x 2.5mm2; while some OCXOs can be as large as 50 x 50mm2, or even larger for certain designs. While some through-hole packages such as dual-in-line 4- or 14-pin types are still used for larger parts (such as OCXOs or dedicated TCXOs), most current designs use surface-mount packages. These surface mount configurations can be hermetically sealed ceramic packages, or FR-4 based components with construction for I/O.

Summarize

Generally, some margin should be left in the device selection to ensure the reliability of the product. Choosing higher-end devices can further reduce the probability of failure and bring potential benefits, which should also be considered when comparing product prices. To make the "overall performance" of the oscillator tend to be balanced and reasonable, it is necessary to weigh factors such as stability, operating temperature range, crystal aging effects, phase noise, cost, etc. The cost here does not only include the price of the device, It also includes the cost of using the product throughout its life.

Detection five skills

1. Use a multimeter (R×10k block) to measure the resistance value at both ends of the crystal oscillator.

If it is infinite, it means that the crystal oscillator has no short circuit or leakage; then insert the test pen into the mains jack, pinch any pin of the crystal oscillator with your fingers, and touch the other pin to the metal part at the top of the test pen. If the neon bulb turns red, the crystal oscillator is good; if the neon bulb does not light up, the crystal oscillator is damaged.

2. Measure its capacitance with a digital capacitance meter (or the capacitance file of a digital multimeter).

Generally, the capacity of the damaged crystal is significantly reduced (different crystals have a certain range of normal capacity)

3. Gently shake close to the ear,

If there is sound, it must be bad (the internal crystal has been broken, and the frequency has changed if it is still usable)

4. Test the output pin voltage.

Under normal circumstances, it is about half of the power supply voltage. Because the output is a sine wave (the peak-to-peak value is close to the source voltage), when tested with a multimeter, it is almost half.

5. Measure with substitution method or oscilloscope.

So how to use a multimeter to measure whether the crystal oscillator is vibrating? You can use a multimeter to measure whether the voltage of the two pins of the crystal oscillator is half of the working voltage of the chip. For example, if the working voltage is 5V, the measured value is about 2.5V. In addition, if you touch the other foot of the crystal with tweezers, the voltage will change significantly, which proves that the vibration is activated.

Summary of 10 major problems that do not vibrate

1. Wrong selection of material parameters causes the crystal oscillator to not vibrate

For example: a MCU needs to match the 6PF 32.768KHz, and the result is 12.5PF, resulting in no vibration.

Solution: replace the model that meets the requirements. If necessary, please confirm with the MCU factory.

2. The internal crystal chip is broken or damaged, resulting in no vibration

For example: damage during transportation, or drop, impact and other factors during use cause damage to the crystal element inside the crystal oscillator, resulting in the crystal oscillator not vibrating.

Solution: replace the good crystal. Usually need to pay attention to: the foam should be thicker during transportation to avoid damage in the middle; during the process, avoid falling, heavy pressure, impact, etc., once the above situations occur, it is forbidden to use it again.

3. The mismatch of the oscillator circuit causes the crystal oscillator to not vibrate

Three indicators that affect the oscillator circuit: frequency error, negative impedance, and excitation level.

(1) The frequency error is too large, causing the actual frequency to deviate from the nominal frequency and causing the crystal oscillator to not vibrate.

Solution: Choose a product with an appropriate PPM value.

(2) If the negative impedance is too large or too small, the crystal oscillator will not vibrate.

Solution: If the negative impedance is too large, you can increase the value of the external capacitors Cd and Cg of the crystal oscillator to reduce the negative impedance; if the negative impedance is too small, you can reduce the value of the external capacitors Cd and Cg of the crystal oscillator to increase the negative impedance. sexual resistance. In general, the negative impedance value should be no less than 3-5 times the nominal maximum impedance of the crystal oscillator.

(3) Excessive or too small excitation level will also cause the crystal oscillator to not vibrate

Solution: Adjust the excitation level of the oscillator circuit to the crystal oscillator output by adjusting the size of Rd in the circuit. Generally speaking, the smaller the excitation level, the better. In addition to low processing power consumption, it is also related to the stability of the oscillation circuit and the service life of the crystal oscillator.

4. Impurities or dust attached to the crystal inside the crystal will also cause the crystal to not vibrate.

For example, one of the manufacturing processes of crystal oscillators is crystal plate electrode plating, that is, a layer of gold or silver electrodes is plated on the crystal plate, which is required to be completed in a 10,000-level dust-free workshop.

If dust particles in the air are attached to the electrodes, or there are gold slag and silver slag remaining on the electrodes, it will also cause the crystal oscillator to not vibrate.

Solution: replace with a new crystal. When choosing a crystal oscillator supplier, it is necessary to consider the manufacturer's equipment, workshop environment, technology and process capabilities, which are related to product quality issues.

5. The crystal oscillator has air leakage and does not vibrate

For example: the crystal oscillator is required to be evacuated and filled with nitrogen during the manufacturing process. If the pressure seal is not good, the air tightness of the crystal oscillator is not good, resulting in air leakage. The crystal oscillator has poor air tightness; it will cause the crystal oscillator to not vibrate.

Solution: replace the good crystal. In the manufacturing process and welding process, the operation must be standardized to avoid product damage caused by misoperation.

6. The temperature is too high or the time is too long during welding, resulting in abnormal internal electrical performance indicators of the crystal oscillator and causing the crystal oscillator to not vibrate

For example: Take the 32.768KHz in-line type as an example, it is required to use solder with a melting point of 178°C, and the temperature inside the crystal oscillator exceeds 150°C, which will cause deterioration of the crystal oscillator characteristics or no vibration. When soldering pins, within 5 seconds at 280°C or within 10 seconds at 260°C.

Do not directly solder the root of the lead, which will also cause deterioration of the crystal characteristics or no vibration.

Solution: During the welding process, the operation must be standardized, and the setting of the welding time and temperature must meet the requirements of the crystal oscillator. If you have any questions, please contact us to confirm.

7. Improper storage environment leads to the deterioration of the electrical performance of the crystal oscillator and causes no vibration

For example, long-term use or storage under conditions of high temperature, low temperature or high humidity will cause the electrical performance of the crystal oscillator to deteriorate, which may lead to no vibration.

Solution: Use and store it under normal temperature and humidity conditions as much as possible to avoid damping the crystal oscillator or circuit board.

8. MCU quality problems, software problems, etc. cause the crystal oscillator to not vibrate

For example, at present, the MCU products are mixed with new products, refurbished products, dismantled products, and OEM products.

This circuit is prone to problems, resulting in the oscillator circuit not working.

In addition, even if it is a genuine MCU, if there is a problem with the programming program, the crystal oscillator may not be able to vibrate.

9. The EMC problem causes the crystal oscillator to not vibrate

For example: Generally speaking, metal packaged products are better than ceramic packaged products in anti-electromagnetic interference. If the EMC on the circuit is large, metal packaged products should be used as much as possible.

In addition, do not run signal lines under the crystal oscillator to avoid interference.

10. Other...

Summary of 7 major problems

1. The frequency offset exceeds the normal value

Original: 1: When the center frequency of the circuit is positively biased, it means that the CL is too small.

Solution: You can increase the value of the external capacitors Cd and Cg of the crystal oscillator.

Reason 2: When the center frequency of the circuit is negatively biased, it means that CL is too large.

Solution: You can reduce the value of the external capacitors Cd and Cg of the crystal oscillator.

2. The crystal oscillator becomes hot during work, and the vibration stops gradually.

Reason: Excluding the influence of the working environment temperature on it, the most likely situation is that the excitation level is too large.

Solution: reduce the excitation level DL, and increase Rd to adjust DL.

3. The crystal oscillator gradually stops vibrating during work, and the crystal oscillator pins start to work again by touching it with your hand or heating it with an electric soldering iron.

Reason: This happens because the negative impedance value in the oscillator circuit is too small.

Solution: It is necessary to adjust the values of the external capacitors Cd and Cg of the crystal oscillator to meet the loop gain of the oscillation circuit.

4. The crystal oscillator is soldered or the pins and pads do not eat tin

Reason: In this case, the pins are generally oxidized, or the pin plating is peeled off.

Solution: The storage environment of the crystal oscillator is very important. Store it under normal temperature and humidity to avoid moisture. In addition, the peeling of the crystal pin plating may be related to the process technology of the crystal oscillator manufacturer or the SMT manufacturer, and further confirmation is required.

5. Try two different crystal oscillator manufacturers for the same product, and the results are different

Reason: This situation is easy to understand. Different manufacturers have different materials, manufacturing processes, etc., which will lead to slight differences in specifications. For example, the same frequency offset is +/-10ppm, most of A may be positive offset, and most of B may be negative offset.

Solution: Generally speaking, in this case, if it is a radio frequency product, it is best to ask the crystal oscillator manufacturer to help do some circuit matching tests, so as to ensure the best circuit matching. If it is a non-RF product, it is generally compatible with the same indicators.

6. The crystal shell falls off

Reason: Sometimes the crystal oscillator will fall off after reflow soldering; some are caused by the crystal oscillator being impacted by external force and other reasons.

Solution: Before the crystal oscillator undergoes reflow soldering, the SMT factory should fully confirm whether the furnace temperature curve meets the furnace passing requirements of the crystal oscillator. Generally speaking, the datasheet provided by the regular crystal oscillator manufacturer will provide reference values.

If it is caused by external factors, try to avoid this situation.

7. Other...

List of crystal oscillator frequency application fields

Take the electronic fence as an example

Electronic fence classification:

1. Pulse electronic fence

The pulse electronic fence is an intelligent perimeter system composed of a pulse generator (host) and a front-end fence. It has the perimeter prevention function of high security level such as anti-theft and alarm. It has the advantages of low false alarm rate, no terrain and environmental restrictions, and high security.

2. Tension electronic fence

The tension type electronic fence perimeter alarm system is a collection of electromechanical devices that prevent illegal overcoming obstacles and sensing, transmission (alarm) tension and pressure, and shear obstacle information. It is a safe, reliable, economical and digitally intelligent perimeter anti-intrusion system. alarm system.

It consists of two parts: alarm controller (host) and electronic fence. The tension type electronic fence can always be loyal to its duty in harsh environments such as wind and frost, rain and snow, dense fog, sand and dust, high temperature and low temperature, and work stably and reliably all day long.

3. GPS electronic fence

The GPS electronic fence can limit the driving area and driving route of the vehicle, and set the driving path of the vehicle in three ways: administrative division, polygonal area, and planned route.

Common frequency points of security crystal oscillators: 12.000MHz, 21.400MHz, 18.9375MHz, 19.069928MHz, 28.375MHz, 28.63636MHz, 37.875MHz, 13.560MHz, 24.000MHz, 12.270MHz and so on.

The main frequencies used by the walkie-talkie are: 21.400MHz, 21.7000MHz.

List of crystal oscillator applications

Application areas: 1. Mobile handheld devices 2. Consumer electronics 3. Smart home 4. Communication networks 5. Automotive electronics 6. Medical electronics 7. Industry 8. Military 9. Aviation ......

Specific application examples:

1. Mobile phone

Specifically: 3225 SMD crystal oscillator, specification 26M--7.3PF 10PPM, and plug-in (DIP) 2*6, 3*8 volume 32.768KHz-12.5PF-10-20PPM cylindrical plug-in crystal oscillator.

2. Mobile NFC

1. Mobile payment function: subway, bus, etc.

2. Verification and authentication functions: car locks, community access control, etc.

3. Data transmission function: upload pictures, music, etc.

......

Hardware support key: frequency of crystal oscillator

NFC technology uses the frequency of 13.56MHz as the basic carrier. The commonly used frequencies are 13.560MHz and 27.120MHz, and the frequency component that generates the frequency is the crystal oscillator. The quality of the crystal oscillator directly affects the use of the entire technology or machine.

3. Desktop computer

Crystal oscillators are used in various components on a desktop computer, and the computer motherboard is the core. Generally, several crystal oscillators are used on a computer motherboard.

Specifically: 14.318MHz clock crystal oscillator, 32.768KHz real crystal oscillator, 24.576MHz sound card crystal oscillator, 25MHz network card crystal oscillator.

Fourth, the router

Specific: 5032mm, 3225mm, 2520mm quartz crystal oscillator

5. Air conditioning

The air conditioner mainly uses cylindrical series crystal oscillators. In the crystal oscillator circuit, if there is a problem with the crystal oscillator, it will cause the entire air conditioner to malfunction. In addition, because the brand and function of the air conditioner are different, the selected crystal oscillator will also be different.

Specifically: there are crystal oscillators such as 32.768KHZ, 4.000MHZ and 4.194304MHZ.

6. Automotive electronics

The main crystal oscillator systems are:

1. Safety control system

Including: engine control, wire-controlled steering system, transmission, airbag, anti-lock braking system, tire pressure detection system, electric power steering system.

2. Information intelligence system

Including: car audio, car navigation system, data bus system, surveillance camera, reversing radar, high security wire control system.

3. Intelligent transportation system

Including: non-stop toll collection system, road traffic information communication, railway car number automatic identification system, automatic highway system, advanced safety vehicle, global intelligent transportation system.

4. Body system

Car clock, timer, instrument panel, wireless remote control door lock, car air conditioner, automatic window control, car anti-theft system.

specific:

The temperature compensated crystal oscillator 2520 crystal oscillator and the 3225 crystal oscillator have the characteristics of small size and good performance, which have become the first choice for GPS navigation in the car.

The 3225-26M/16M chip crystal oscillator needs to be used in the car bluetooth, which can push songs fast and transmit data with zero distance.

The automotive digital display system will use a SMD 32.768K crystal oscillator.

The 2*6 series cylindrical crystal oscillator used in the driving recorder. It also belongs to the 32.768K series, and 32.768K belongs to the time system. Any product related to time needs this series of crystal oscillators. The 32.768K crystal oscillator is used to display the time. . And the range of use is very wide. Such as dashboards, speedometers, electronic road pricing black boxes, battery management units and car radios.

Taiwan Jiashuo is the parts division of the former Motorola (MOTOROLA) company. The crystal oscillators and filters produced by TST Jiashuo retain Motorola's technology, but have the price of Taiwan products, and the cost performance is very high. The range of applications is very wide, including the aerospace level. And the products are also compared, such as surface acoustic wave filter, radio frequency filter, temperature compensated crystal oscillator, voltage controlled crystal oscillator, constant temperature crystal oscillator, etc. Welcome to contact us for research and development and provide original technical support.