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• Q

Is the crystal oscillator circuit the same as the clock circuit?

Crystal oscillator circuit is a common form of clock circuit, but not all clock circuits are crystal oscillator circuits. A clock circuit is an oscillating circuit that generates accurate motion like a clock, and any operation is in chronological order. The circuit used to generate this time is called a clock circuit. It is generally composed of crystal oscillators, crystal oscillator control chips, and capacitors, and is widely used, such as the clock circuit of computers, the clock circuit of electronic watches, and the clock circuit of MP3MP4. Crystal oscillator circuit is a special type of clock circuit, which is usually controlled by a crystal oscillator as the main component to generate an oscillating clock. This type of circuit is common in IT (communication products, CNC products, microcontrollers, computers) main components because it can provide a normal oscillation clock for the main control processor. Therefore, crystal oscillator circuits are a special form of clock circuits, but not all clock circuits are crystal oscillator circuits.

• Q

What is the relationship between crystal oscillator units and conversion units?

The unit of a crystal oscillator is hertz (Hz), and the commonly used units are kilohertz (KHz) and megahertz (MHz). The conversion relationship between them is 1MHZ=1000KHZ=1000000HZ. Crystal oscillator is a general term for crystal resonator and crystal oscillator, which is a component made by cutting natural mineral - quartz in a certain direction. In circuits, the letters XL or OS are generally used instead. Crystal oscillator is a frequency component, which can be divided into resonators, oscillators, and filters. The most common frequency in crystal oscillator is 32.768KHZ. The role of crystal oscillators in circuit boards is, in simple terms, to convert unwanted frequencies into desired ones.

• Q

How to calculate the formula for crystal oscillator load capacitance?

Cf=[Cd * Cg/(Cd+Cg)]+Cic+△ C Among them, Cd and Cg are connected to the two pins of the crystal oscillator and the capacitance to ground, respectively. The empirical value of Cic (internal capacitance of integrated circuits)+△ C (capacitance on PCB) is 3 to 5pf. It should be noted that different IC and PCB materials may vary, so adjustments need to be made according to the actual situation.

• Q

Why do we need crystal oscillators on PCB boards

Because crystal oscillators are the most important component in clock circuits, their main function is to provide reference frequencies to various parts of accessories such as graphics cards, network cards, and motherboards. It is like a ruler, unstable working frequency can cause unstable working frequency of related equipment, which is prone to problems. In addition, another function of a crystal oscillator is to provide the basic clock signal for the system. Typically, a system shares a crystal oscillator, making it easier for each part to maintain synchronization. Some communication systems use different crystal oscillators for the fundamental frequency and radio frequency, and maintain synchronization through electronic frequency adjustment.

• Q

What is the working temperature range of a crystal oscillator?

The working temperature range of a crystal oscillator refers to the temperature range within which it can operate normally, usually determined by the temperature limitations of the crystal resonator and packaging materials. The common operating temperature range of crystal oscillators in the market is generally industrial grade -40 ℃~+85 ℃, and some crystal oscillators used in high-end electronic products can even operate normally in the temperature range of -55 ℃ to+125 ℃. In low-temperature environments, due to the high impedance of crystal resonators, the output power of the driving circuit may be too small, which affects the stability and distortion of the output waveform. In high-temperature environments, water vapor and impurities in the crystal resonator will evaporate, leading to a decrease in resonant frequency and affecting the accuracy and stability of the crystal oscillator. In addition, in extreme high or low temperature environments, the packaging material of the crystal oscillator may also be affected by thermal expansion and contraction, leading to the rupture or failure of the crystal oscillator. When selecting a crystal oscillator, it is necessary to consider the environmental temperature range of the product's operation, the required accuracy and stability, the quality of packaging materials and production processes, and cost factors.

• Q

What is the vacuum degree required for crystal oscillator production?

Generally speaking, in order to ensure the quality of crystal oscillators, the vacuum degree during the production process needs to reach 10 ^ -6 Torr or lower. Only in such an environment can the impact of impurities and moisture in the air on the performance of crystal oscillators be minimized to the greatest extent possible. In addition, vacuum degree is also an important process parameter in the manufacturing process of crystal oscillators. By controlling the level of vacuum, the manufacturing process of crystal oscillators can be better controlled, thereby obtaining higher quality crystal oscillators.

• Q

Is the crystal oscillator produced by the original factory genuine?

The crystal oscillator produced by the original factory is genuine, that is, the original factory genuine product. Because the original crystal oscillator factory will undergo crystal oscillator testing, only after passing the testing will the next process, which is laser printing, proceed. Printing is carried out using laser printing. After being adjusted by the laser machine, there are strict specifications for the intensity and angle of the laser. The overall proportion of the printing size is appropriate, clear and neat, and it looks very comfortable. This is done in order to facilitate customers or manufacturers to trace back and conduct product cause analysis in case of crystal oscillator quality problems. However, it is not enough to judge a crystal oscillator as genuine solely based on its original production. Some unscrupulous merchants may use counterfeit and inferior crystal oscillators to deceive consumers. Therefore, when purchasing crystal oscillators, it is necessary to choose reliable channels and brands.

• Q

What is the difference between active and passive crystal oscillators?

The main differences between active and passive crystal oscillators are as follows: 1. Composition and structure: The active crystal oscillator contains crystals and peripheral circuits inside, and can directly output signals by providing an external voltage source. It generally has four pins, one for power supply, one for grounding, one for signal output, and one for NC (empty pin). Passive crystal oscillators have only one crystal and must be combined with peripheral circuits to form an oscillator that can output signals of a specific frequency, and this oscillator needs to provide power. 2. Performance and accuracy: The accuracy of active crystal oscillators can reach 0.1ppm, while the highest accuracy of passive crystal oscillators is 5ppm. The higher the accuracy, the better the frequency stability. In addition, active crystal oscillators have better stability than passive crystal oscillators, but they also have their own small defects such as fixed signal levels. 3. Cost and convenience: Passive crystal oscillator circuits are more cost-effective, while active crystal oscillator circuits are superior in product performance. The choice between using active or passive crystal oscillators depends on specific usage requirements and product characteristics.

• Q

What is the structure and principle of crystal oscillators?

The structure and principle of crystal oscillators are as follows: 1. Structure of crystal oscillator: The core of crystal oscillator is quartz crystal, which has an important characteristic. If an alternating voltage is applied to it, it will generate mechanical oscillation. Conversely, if mechanical vibration is applied, it will generate alternating voltage, which is called electromechanical effect. 2. Working principle of crystal oscillator: The loss of quartz crystal is very small, which means that the Q value is very high. As an oscillator, it can generate very stable oscillations. When used as a filter, it can obtain a very stable and steep bandpass curve or bandstop curve.

• Q

What are the conditions for passive crystal oscillators to vibrate?

The starting conditions of passive crystal oscillators are mainly affected by circuit environmental conditions and external load conditions. 1. Circuit environmental conditions: The power supply voltage Vcc and the working static current Icc of the components in the circuit are the main circuit environmental conditions that affect the initiation of passive crystal oscillators. There are usually other static currents on the circuit, which should also be carefully considered to avoid wasting electrical energy. 2. External load conditions: External load conditions refer to the parameters and structure of the external circuits in the system, which greatly affect the performance of the system. When an external load is applied, the frequency of the system will change, causing a change in amplitude, which in turn affects the normal operation of the oscillator. In addition, the parameters and structure of the components in the external load can also affect the stability of the oscillator. When designing wiring, generally no wiring is required under the crystal oscillator. Shielding should be added around the crystal oscillator, and external capacitors should be placed as close to the IC ground as possible instead of away from the IC ground. Otherwise, even if the crystal oscillator starts to vibrate, it is more susceptible to interference from peripheral stray signals, resulting in unstable output frequency signals or frequency offset, which directly affects the normal operation of the IC. In addition, it is important to note that changes in circuit board temperature and fluctuations in circuit voltage can interfere with the frequency of the crystal oscillator.

• Q

Do crystal oscillators have positive and negative poles?

Passive crystal oscillators (commonly known as crystal oscillators) do not have positive or negative electrodes. It is an electronic component composed of crystals, resonant circuits, and packaging, and its internal structure does not have a positive and negative electrode like a battery. When using a crystal oscillator in a circuit, it is necessary to connect the pins of the oscillator to a suitable circuit and design and connect the circuit correctly according to the specifications of the oscillator.

• Q

How is the frequency of a crystal oscillator calculated?

The frequency calculation formula for crystal oscillators is: f=1/(2 * π * C * √ (L * C)). Among them, f represents the output frequency of the crystal oscillator, C represents the capacitance of the crystal oscillator, and L represents the inductance of the crystal oscillator. In practical applications, the capacitance and inductance of crystal oscillators are usually fixed, therefore, the C and L in the crystal oscillator frequency calculation formula are known. Substitute the known C and L into the formula to obtain the output frequency of the crystal oscillator. The resonant frequency of the crystal depends on the physical size and material of the crystal oscillator.

• Q

How to test if the crystal oscillator is working properly?

The following three methods can be used to test whether the crystal oscillator is working properly: 1. Oscilloscope detection method: When the crystal oscillator is excited, it will generate a sine wave. It is appropriate to view the waveform representing the sine wave on the clock pin. If the clock cannot function properly, please replace the crystal oscillator. When the monitor came in, there were no symptoms of high voltage. When checking the crystal with an oscilloscope, it was found that the waveform was very unstable. Replacing the microprocessor solved the problem of no high voltage, and the crystal oscillator waveform displayed a perfect sine wave. 2. Frequency counter detection method: Measurement must be carried out when the device power is turned on. Place the probe of the instrument or frequency counter on the crystal oscillator pin and read the measurement value. Ensure that the range of the frequency counter table used is higher than the crystal oscillator frequency being checked. If the crystal oscillator is 8 mhz, the instrument used should have a range that can check the frequency. Assuming the reading of the crystal oscillator is 2.5 mhz, it can be inferred that the crystal oscillator is not functioning properly and needs to be replaced. 3. Test circuit detection method: Display devices can display characters and symbols, and their application in electronic devices is becoming increasingly widespread. The above three methods can all be used to test whether the crystal oscillator is working properly, and the specific methods may vary depending on different devices and application scenarios.

• Q

What is the reason why crystal oscillators start vibrating but the frequency is incorrect

1. Poor or reversed contact of crystal oscillator pins. 2. The crystal oscillator frequency is incorrect and needs to be replaced. 3. Check the quality of the crystal oscillator itself to ensure that it meets the specifications. 4. Check the temperature and electromagnetic interference of the surrounding environment to minimize their impact on the crystal oscillator as much as possible. 5. Add a temperature compensation circuit to the crystal oscillator circuit to improve frequency stability. The clock source of the MCU itself is faulty and needs to be checked or replaced.

• Q

Why does the crystal oscillator not vibrate?

1. The crystal oscillator has no interrupt or the interrupt is not properly connected; 2. The transistor pins are reversed, or the crystal oscillator pins are reversed; 3. The crystal oscillator frequency is incorrect and may need to be replaced.

• Q

Why use crystal oscillators as oscillators?

The main reasons for using crystal oscillators as oscillators are as follows: 1. Good frequency stability: The oscillation frequency generated by crystal oscillators has excellent stability, and its accuracy is much higher than other oscillation components. 2. Easy to design: Crystal oscillators have advantages such as easy design and simple circuit design. 3. High quality factor: Crystal is a material with high hardness and a high quality factor, which gives vibrators high frequency accuracy and stability. 4. Good temperature stability: The frequency stability of crystal oscillators is not affected by temperature, so they can maintain a stable oscillation frequency under various temperature conditions. 5. Strong resistance to electromagnetic interference: Crystal oscillators have strong resistance to electromagnetic interference, so they can maintain stable oscillation frequencies even in complex electromagnetic environments. 6. Long lifespan: The crystal oscillator has a long lifespan and can work stably for a long time. 7. Suitable for precision measurement and communication: Due to its high precision, high stability, and good anti-interference ability, crystal oscillators are widely used in the field of precision measurement and communication. Crystal oscillators have excellent performance in various aspects, and are therefore widely used in various situations that require high precision, high stability, and strong anti-interference ability.

• Q

Why can't crystal oscillators and quartz oscillators fall?

When they fall, it may cause chip fragmentation and other factors. Especially the thickness of the crystal oscillator chip is very thin, for example, the 25MHz crystal oscillator has a thickness of about 0.0668mm, which makes it relatively fragile and vulnerable to damage.

• Q

What impact will a low power supply design have on the oscillator?

The impact of low power supply design on oscillators is mainly reflected in the design of high-frequency oscillators (OSCILLATOR). This mainly brings two problems: When designing high-frequency OSCILLATOR, it may face low high-frequency gain and high CRYSTAL equivalent resistance of the amplifier. That is to say, a low power supply design may affect the performance of the oscillator at high frequencies, leading to insufficient gain or high resistance, thereby affecting the stability and accuracy of the oscillator. 2. Negative impedance problem. Negative impedance refers to the impedance characteristic value of the oscillating circuit at the oscillation frequency when viewed from the two terminals of the quartz crystal resonator towards the oscillating circuit. This characteristic value may change due to low power supply design, affecting the performance of the oscillator. Please note that these impacts may vary depending on the specific details of the oscillator design and power supply design. When designing and implementing power systems, these factors should be fully considered to optimize the performance of the oscillator. If necessary, you can seek the help of experts in the relevant field for design and optimization.

• Q

What is PPM? How to calculate?

Part Per Million refers to a frequency jump value of one millionth; The ppm value is obtained by subtracting the target frequency from the actual frequency, dividing it by the target frequency, and moving the decimal point back six digits. Example: The target frequency is 25.00000MHz, but the actual frequency is 25.000015MHz (25.000015-25.000000)/25.00000=0.0000006. Move the decimal point back six digits, which is 0.6ppm.

• Q

What is a car grade crystal oscillator?

Car grade crystal oscillator refers to a crystal oscillator used in the automotive electronics field, certified by AEC-Q100/200, with higher anti-interference and stability, and able to adapt to harsh working environments.

• Q

How to choose a suitable crystal oscillator load?

Choosing a suitable crystal oscillator load requires considering multiple factors, including crystal oscillator frequency, load circuit environment, noise level, and stability requirements. If not selected properly, it will affect circuit performance, so it is necessary to combine specific application scenarios for selection.

• Q

How to determine the load size of the crystal oscillator?

The size of the crystal oscillator load is usually determined by the crystal oscillator manufacturer and can be found in the crystal oscillator data manual. Generally speaking, the size of the crystal oscillator load is related to the crystal oscillator frequency and circuit environment, and needs to be selected according to specific application scenarios.

• Q

What are the common specifications of crystal oscillator loads?

The common specifications of crystal oscillator loads include 12.5pF, 18pF, 20pF, 22pF, etc. Different crystal oscillator manufacturers and products may have different load specifications, which need to be selected according to the actual situation.

• Q

What is the impact of crystal oscillator load on the system?

The size of the crystal oscillator load will affect the resonant frequency and oscillation stability of the crystal oscillator. If the load capacitance is too small, it will cause the crystal oscillator frequency to be too high and the oscillation stability to deteriorate; If the load capacitance is too large, it will cause the crystal oscillator frequency to be low and the oscillation amplitude to decrease.

• Q

What is the meaning of CL in the manufacturer's specification sheet?

It refers to the load capacitor added during the production of an oscillator, usually expressed as CL. It is the load capacitor that needs to be connected to the crystal oscillator during normal operation, used to form a resonant circuit with the resonator itself and external circuits, so that the oscillation frequency can be accurate.

• Q

What is the working principle of crystal oscillators?

The working principle of crystal oscillator is to use the piezoelectric effect of quartz to apply an alternating electric field through an external circuit, causing crystal vibration to produce resonance.

• Q

What are the common types of crystal oscillators?

Crystal oscillator, also known as crystal oscillator, is an electronic component used to generate stable frequencies. According to different functions and implementation technologies, crystal oscillators can be classified into various types. The following are some common types of crystal oscillators: ordinary passive resonators (low-frequency KHz/high-frequency Mhz), passive crystal oscillators with built-in thermistors (TSX), ordinary crystal oscillators (SPXO), voltage controlled crystal oscillators (VCXO), constant temperature crystal oscillators (OCXO), temperature compensated crystal oscillators (TCXO), etc

• Q

What is a crystal oscillator and its role

Crystal oscillator is a commonly used electronic component used to generate stable high-precision electrical signals. Provide chips such as CPU, DSP, FPGA, etc. to ensure the normal operation of the system.

• Q

Is the crystal oscillator circuit the same as the clock circuit?

Crystal oscillator circuit is a common form of clock circuit, but not all clock circuits are crystal oscillator circuits. A clock circuit is an oscillating circuit that generates accurate motion like a clock, and any operation is in chronological order. The circuit used to generate this time is called a clock circuit. It is generally composed of crystal oscillators, crystal oscillator control chips, and capacitors, and is widely used, such as the clock circuit of computers, the clock circuit of electronic watches, and the clock circuit of MP3MP4. Crystal oscillator circuit is a special type of clock circuit, which is usually controlled by a crystal oscillator as the main component to generate an oscillating clock. This type of circuit is common in IT (communication products, CNC products, microcontrollers, computers) main components because it can provide a normal oscillation clock for the main control processor. Therefore, crystal oscillator circuits are a special form of clock circuits, but not all clock circuits are crystal oscillator circuits.

• Q

What is the relationship between crystal oscillator units and conversion units?

The unit of a crystal oscillator is hertz (Hz), and the commonly used units are kilohertz (KHz) and megahertz (MHz). The conversion relationship between them is 1MHZ=1000KHZ=1000000HZ. Crystal oscillator is a general term for crystal resonator and crystal oscillator, which is a component made by cutting natural mineral - quartz in a certain direction. In circuits, the letters XL or OS are generally used instead. Crystal oscillator is a frequency component, which can be divided into resonators, oscillators, and filters. The most common frequency in crystal oscillator is 32.768KHZ. The role of crystal oscillators in circuit boards is, in simple terms, to convert unwanted frequencies into desired ones.

• Q

How to calculate the formula for crystal oscillator load capacitance?

Cf=[Cd * Cg/(Cd+Cg)]+Cic+△ C Among them, Cd and Cg are connected to the two pins of the crystal oscillator and the capacitance to ground, respectively. The empirical value of Cic (internal capacitance of integrated circuits)+△ C (capacitance on PCB) is 3 to 5pf. It should be noted that different IC and PCB materials may vary, so adjustments need to be made according to the actual situation.

• Q

Why do we need crystal oscillators on PCB boards

Because crystal oscillators are the most important component in clock circuits, their main function is to provide reference frequencies to various parts of accessories such as graphics cards, network cards, and motherboards. It is like a ruler, unstable working frequency can cause unstable working frequency of related equipment, which is prone to problems. In addition, another function of a crystal oscillator is to provide the basic clock signal for the system. Typically, a system shares a crystal oscillator, making it easier for each part to maintain synchronization. Some communication systems use different crystal oscillators for the fundamental frequency and radio frequency, and maintain synchronization through electronic frequency adjustment.

• Q

What is the working temperature range of a crystal oscillator?

The working temperature range of a crystal oscillator refers to the temperature range within which it can operate normally, usually determined by the temperature limitations of the crystal resonator and packaging materials. The common operating temperature range of crystal oscillators in the market is generally industrial grade -40 ℃~+85 ℃, and some crystal oscillators used in high-end electronic products can even operate normally in the temperature range of -55 ℃ to+125 ℃. In low-temperature environments, due to the high impedance of crystal resonators, the output power of the driving circuit may be too small, which affects the stability and distortion of the output waveform. In high-temperature environments, water vapor and impurities in the crystal resonator will evaporate, leading to a decrease in resonant frequency and affecting the accuracy and stability of the crystal oscillator. In addition, in extreme high or low temperature environments, the packaging material of the crystal oscillator may also be affected by thermal expansion and contraction, leading to the rupture or failure of the crystal oscillator. When selecting a crystal oscillator, it is necessary to consider the environmental temperature range of the product's operation, the required accuracy and stability, the quality of packaging materials and production processes, and cost factors.

• Q

What is the vacuum degree required for crystal oscillator production?

Generally speaking, in order to ensure the quality of crystal oscillators, the vacuum degree during the production process needs to reach 10 ^ -6 Torr or lower. Only in such an environment can the impact of impurities and moisture in the air on the performance of crystal oscillators be minimized to the greatest extent possible. In addition, vacuum degree is also an important process parameter in the manufacturing process of crystal oscillators. By controlling the level of vacuum, the manufacturing process of crystal oscillators can be better controlled, thereby obtaining higher quality crystal oscillators.

• Q

Is the crystal oscillator produced by the original factory genuine?

The crystal oscillator produced by the original factory is genuine, that is, the original factory genuine product. Because the original crystal oscillator factory will undergo crystal oscillator testing, only after passing the testing will the next process, which is laser printing, proceed. Printing is carried out using laser printing. After being adjusted by the laser machine, there are strict specifications for the intensity and angle of the laser. The overall proportion of the printing size is appropriate, clear and neat, and it looks very comfortable. This is done in order to facilitate customers or manufacturers to trace back and conduct product cause analysis in case of crystal oscillator quality problems. However, it is not enough to judge a crystal oscillator as genuine solely based on its original production. Some unscrupulous merchants may use counterfeit and inferior crystal oscillators to deceive consumers. Therefore, when purchasing crystal oscillators, it is necessary to choose reliable channels and brands.

• Q

What is the difference between active and passive crystal oscillators?

The main differences between active and passive crystal oscillators are as follows: 1. Composition and structure: The active crystal oscillator contains crystals and peripheral circuits inside, and can directly output signals by providing an external voltage source. It generally has four pins, one for power supply, one for grounding, one for signal output, and one for NC (empty pin). Passive crystal oscillators have only one crystal and must be combined with peripheral circuits to form an oscillator that can output signals of a specific frequency, and this oscillator needs to provide power. 2. Performance and accuracy: The accuracy of active crystal oscillators can reach 0.1ppm, while the highest accuracy of passive crystal oscillators is 5ppm. The higher the accuracy, the better the frequency stability. In addition, active crystal oscillators have better stability than passive crystal oscillators, but they also have their own small defects such as fixed signal levels. 3. Cost and convenience: Passive crystal oscillator circuits are more cost-effective, while active crystal oscillator circuits are superior in product performance. The choice between using active or passive crystal oscillators depends on specific usage requirements and product characteristics.

• Q

What is the structure and principle of crystal oscillators?

The structure and principle of crystal oscillators are as follows: 1. Structure of crystal oscillator: The core of crystal oscillator is quartz crystal, which has an important characteristic. If an alternating voltage is applied to it, it will generate mechanical oscillation. Conversely, if mechanical vibration is applied, it will generate alternating voltage, which is called electromechanical effect. 2. Working principle of crystal oscillator: The loss of quartz crystal is very small, which means that the Q value is very high. As an oscillator, it can generate very stable oscillations. When used as a filter, it can obtain a very stable and steep bandpass curve or bandstop curve.

• Q

What are the conditions for passive crystal oscillators to vibrate?

The starting conditions of passive crystal oscillators are mainly affected by circuit environmental conditions and external load conditions. 1. Circuit environmental conditions: The power supply voltage Vcc and the working static current Icc of the components in the circuit are the main circuit environmental conditions that affect the initiation of passive crystal oscillators. There are usually other static currents on the circuit, which should also be carefully considered to avoid wasting electrical energy. 2. External load conditions: External load conditions refer to the parameters and structure of the external circuits in the system, which greatly affect the performance of the system. When an external load is applied, the frequency of the system will change, causing a change in amplitude, which in turn affects the normal operation of the oscillator. In addition, the parameters and structure of the components in the external load can also affect the stability of the oscillator. When designing wiring, generally no wiring is required under the crystal oscillator. Shielding should be added around the crystal oscillator, and external capacitors should be placed as close to the IC ground as possible instead of away from the IC ground. Otherwise, even if the crystal oscillator starts to vibrate, it is more susceptible to interference from peripheral stray signals, resulting in unstable output frequency signals or frequency offset, which directly affects the normal operation of the IC. In addition, it is important to note that changes in circuit board temperature and fluctuations in circuit voltage can interfere with the frequency of the crystal oscillator.

• Q

Do crystal oscillators have positive and negative poles?

Passive crystal oscillators (commonly known as crystal oscillators) do not have positive or negative electrodes. It is an electronic component composed of crystals, resonant circuits, and packaging, and its internal structure does not have a positive and negative electrode like a battery. When using a crystal oscillator in a circuit, it is necessary to connect the pins of the oscillator to a suitable circuit and design and connect the circuit correctly according to the specifications of the oscillator.

• Q

How is the frequency of a crystal oscillator calculated?

The frequency calculation formula for crystal oscillators is: f=1/(2 * π * C * √ (L * C)). Among them, f represents the output frequency of the crystal oscillator, C represents the capacitance of the crystal oscillator, and L represents the inductance of the crystal oscillator. In practical applications, the capacitance and inductance of crystal oscillators are usually fixed, therefore, the C and L in the crystal oscillator frequency calculation formula are known. Substitute the known C and L into the formula to obtain the output frequency of the crystal oscillator. The resonant frequency of the crystal depends on the physical size and material of the crystal oscillator.

• Q

How to test if the crystal oscillator is working properly?

The following three methods can be used to test whether the crystal oscillator is working properly: 1. Oscilloscope detection method: When the crystal oscillator is excited, it will generate a sine wave. It is appropriate to view the waveform representing the sine wave on the clock pin. If the clock cannot function properly, please replace the crystal oscillator. When the monitor came in, there were no symptoms of high voltage. When checking the crystal with an oscilloscope, it was found that the waveform was very unstable. Replacing the microprocessor solved the problem of no high voltage, and the crystal oscillator waveform displayed a perfect sine wave. 2. Frequency counter detection method: Measurement must be carried out when the device power is turned on. Place the probe of the instrument or frequency counter on the crystal oscillator pin and read the measurement value. Ensure that the range of the frequency counter table used is higher than the crystal oscillator frequency being checked. If the crystal oscillator is 8 mhz, the instrument used should have a range that can check the frequency. Assuming the reading of the crystal oscillator is 2.5 mhz, it can be inferred that the crystal oscillator is not functioning properly and needs to be replaced. 3. Test circuit detection method: Display devices can display characters and symbols, and their application in electronic devices is becoming increasingly widespread. The above three methods can all be used to test whether the crystal oscillator is working properly, and the specific methods may vary depending on different devices and application scenarios.

• Q

What is the reason why crystal oscillators start vibrating but the frequency is incorrect

1. Poor or reversed contact of crystal oscillator pins. 2. The crystal oscillator frequency is incorrect and needs to be replaced. 3. Check the quality of the crystal oscillator itself to ensure that it meets the specifications. 4. Check the temperature and electromagnetic interference of the surrounding environment to minimize their impact on the crystal oscillator as much as possible. 5. Add a temperature compensation circuit to the crystal oscillator circuit to improve frequency stability. The clock source of the MCU itself is faulty and needs to be checked or replaced.

• Q

Why does the crystal oscillator not vibrate?

1. The crystal oscillator has no interrupt or the interrupt is not properly connected; 2. The transistor pins are reversed, or the crystal oscillator pins are reversed; 3. The crystal oscillator frequency is incorrect and may need to be replaced.

• Q

Why use crystal oscillators as oscillators?

The main reasons for using crystal oscillators as oscillators are as follows: 1. Good frequency stability: The oscillation frequency generated by crystal oscillators has excellent stability, and its accuracy is much higher than other oscillation components. 2. Easy to design: Crystal oscillators have advantages such as easy design and simple circuit design. 3. High quality factor: Crystal is a material with high hardness and a high quality factor, which gives vibrators high frequency accuracy and stability. 4. Good temperature stability: The frequency stability of crystal oscillators is not affected by temperature, so they can maintain a stable oscillation frequency under various temperature conditions. 5. Strong resistance to electromagnetic interference: Crystal oscillators have strong resistance to electromagnetic interference, so they can maintain stable oscillation frequencies even in complex electromagnetic environments. 6. Long lifespan: The crystal oscillator has a long lifespan and can work stably for a long time. 7. Suitable for precision measurement and communication: Due to its high precision, high stability, and good anti-interference ability, crystal oscillators are widely used in the field of precision measurement and communication. Crystal oscillators have excellent performance in various aspects, and are therefore widely used in various situations that require high precision, high stability, and strong anti-interference ability.

• Q

Why can't crystal oscillators and quartz oscillators fall?

When they fall, it may cause chip fragmentation and other factors. Especially the thickness of the crystal oscillator chip is very thin, for example, the 25MHz crystal oscillator has a thickness of about 0.0668mm, which makes it relatively fragile and vulnerable to damage.

• Q

What impact will a low power supply design have on the oscillator?

The impact of low power supply design on oscillators is mainly reflected in the design of high-frequency oscillators (OSCILLATOR). This mainly brings two problems: When designing high-frequency OSCILLATOR, it may face low high-frequency gain and high CRYSTAL equivalent resistance of the amplifier. That is to say, a low power supply design may affect the performance of the oscillator at high frequencies, leading to insufficient gain or high resistance, thereby affecting the stability and accuracy of the oscillator. 2. Negative impedance problem. Negative impedance refers to the impedance characteristic value of the oscillating circuit at the oscillation frequency when viewed from the two terminals of the quartz crystal resonator towards the oscillating circuit. This characteristic value may change due to low power supply design, affecting the performance of the oscillator. Please note that these impacts may vary depending on the specific details of the oscillator design and power supply design. When designing and implementing power systems, these factors should be fully considered to optimize the performance of the oscillator. If necessary, you can seek the help of experts in the relevant field for design and optimization.

• Q

What is PPM? How to calculate?

Part Per Million refers to a frequency jump value of one millionth; The ppm value is obtained by subtracting the target frequency from the actual frequency, dividing it by the target frequency, and moving the decimal point back six digits. Example: The target frequency is 25.00000MHz, but the actual frequency is 25.000015MHz (25.000015-25.000000)/25.00000=0.0000006. Move the decimal point back six digits, which is 0.6ppm.

• Q

What is a car grade crystal oscillator?

Car grade crystal oscillator refers to a crystal oscillator used in the automotive electronics field, certified by AEC-Q100/200, with higher anti-interference and stability, and able to adapt to harsh working environments.

• Q

How to choose a suitable crystal oscillator load?

Choosing a suitable crystal oscillator load requires considering multiple factors, including crystal oscillator frequency, load circuit environment, noise level, and stability requirements. If not selected properly, it will affect circuit performance, so it is necessary to combine specific application scenarios for selection.

• Q

How to determine the load size of the crystal oscillator?

The size of the crystal oscillator load is usually determined by the crystal oscillator manufacturer and can be found in the crystal oscillator data manual. Generally speaking, the size of the crystal oscillator load is related to the crystal oscillator frequency and circuit environment, and needs to be selected according to specific application scenarios.

• Q

What are the common specifications of crystal oscillator loads?

The common specifications of crystal oscillator loads include 12.5pF, 18pF, 20pF, 22pF, etc. Different crystal oscillator manufacturers and products may have different load specifications, which need to be selected according to the actual situation.

• Q

What is the impact of crystal oscillator load on the system?

The size of the crystal oscillator load will affect the resonant frequency and oscillation stability of the crystal oscillator. If the load capacitance is too small, it will cause the crystal oscillator frequency to be too high and the oscillation stability to deteriorate; If the load capacitance is too large, it will cause the crystal oscillator frequency to be low and the oscillation amplitude to decrease.

• Q

What is the working principle of crystal oscillators?

The working principle of crystal oscillator is to use the piezoelectric effect of quartz to apply an alternating electric field through an external circuit, causing crystal vibration to produce resonance.

• Q

What are the common types of crystal oscillators?

Crystal oscillator, also known as crystal oscillator, is an electronic component used to generate stable frequencies. According to different functions and implementation technologies, crystal oscillators can be classified into various types. The following are some common types of crystal oscillators: ordinary passive resonators (low-frequency KHz/high-frequency Mhz), passive crystal oscillators with built-in thermistors (TSX), ordinary crystal oscillators (SPXO), voltage controlled crystal oscillators (VCXO), constant temperature crystal oscillators (OCXO), temperature compensated crystal oscillators (TCXO), etc

• Q

What is a crystal oscillator and its role

Crystal oscillator is a commonly used electronic component used to generate stable high-precision electrical signals. Provide chips such as CPU, DSP, FPGA, etc. to ensure the normal operation of the system.

• Q

What is the meaning of CL in the manufacturer's specification sheet?

It refers to the load capacitor added during the production of an oscillator, usually expressed as CL. It is the load capacitor that needs to be connected to the crystal oscillator during normal operation, used to form a resonant circuit with the resonator itself and external circuits, so that the oscillation frequency can be accurate.