Analysis of the advantages and disadvantages of crystal resonators and crystal oscillators

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Analysis of the advantages and disadvantages of crystal resonators and crystal oscillators [Copy link]

Resonators are electronic components that generate resonant frequencies. They are typical passive devices that require peripheral circuits to drive them to work and generate clock outputs. Crystal resonators are commonly divided into quartz crystal resonators and ceramic resonators. They generate frequencies and have the characteristics of stability and good anti-interference performance. They are widely used in various electronic products. The frequency accuracy of quartz crystal resonators is higher than that of ceramic resonators, but the cost is also higher than that of ceramic resonators. Resonators mainly play the role of frequency control. All electronic products involving frequency transmission and reception require resonators. The types of resonators can be divided into two types according to their appearance: direct-insert type and surface-mount type.

A ceramic resonator is a piezoelectric ceramic device that oscillates at a specific frequency. The material used to make this device excites resonance characteristics during the production process. Since this resonance characteristic is within the production tolerance range and its quality factor is much lower than that of quartz, the frequency stability provided by ceramic resonators is not as good as that of crystal resonators. Ceramic resonators are usually used in applications where the cost is low and the performance requirements are not high.

Advantages: Compared to crystals, ceramic resonators cost only half as much and are smaller in size.

Disadvantages: Compared with crystals, it lacks frequency and temperature stability. Its accuracy is poor, about 1% to 0.1%.

An oscillator (English: oscillator) is an energy conversion device that converts direct current into alternating current with a certain frequency. The circuit it forms is called an oscillation circuit. An oscillator is an active device, and an oscillator has one more control circuit than a resonator. An oscillator is an electronic component used to generate repetitive electronic signals (usually sine waves or square waves). The circuit it forms is called an oscillation circuit. An electronic circuit or device that can convert direct current into an alternating current signal output with a certain frequency. There are many types. According to the oscillation excitation method, it can be divided into self-excited oscillators and externally excited oscillators; according to the circuit structure, it can be divided into RC oscillators, LC oscillators, crystal oscillators, tuning fork oscillators, etc.; according to the output waveform, it can be divided into sine wave, square wave, sawtooth wave and other oscillators. It is widely used in the electronics industry, medical treatment, scientific research and other aspects.

Advantages: Crystal oscillator signal quality is good, relatively stable, and the connection method is relatively simple (mainly to do a good job of power supply filtering, usually using a PI filter network composed of a capacitor and an inductor, and a small resistor at the output end to filter the signal), no complex configuration circuit is required. For applications with sensitive timing requirements, the performance of crystal oscillators is relatively good.

Disadvantages: Compared with crystal resonators, the disadvantage of crystal oscillators is that their signal level is fixed, and it is necessary to select the appropriate output level, which is less flexible and more expensive. In addition, quartz oscillators take a long time to start up.

Size: Crystal oscillators are usually larger than passive crystals. With the improvement of technology, some crystal oscillators are now surface-mounted and have a size comparable to that of crystal resonators.

Overview: Typical initial accuracy of ceramic resonators is in the 0.5% to 0.1% range, and drift due to aging or temperature changes may change this accuracy range. Inexpensive ceramic resonators have a tolerance of only ±1.1%, while higher-end automotive accuracies are ±0.25% and ±0.3%, respectively. Future applications are in automotive CAN (Controller Area Network) bus applications, operating temperature is -40°C to +125°C. Low-cost ceramic resonators with frequencies of 200 KHZ to about 1 GHZ are suitable for embedded systems where timing requirements are not strict. Ceramic devices start faster and are generally smaller than quartz devices. They are also more resistant to shock and vibration.