As one of the common components in electronic devices, crystal oscillators play an important role in many circuits. For beginners, it may be confusing whether a crystal oscillator has a positive and negative electrode, and what its specific function and principle are. This article will deeply analyze the structure, working principle and function of crystal oscillator, and understand the mystery of crystal oscillator.
Structure:
The structure of the crystal oscillator is relatively simple, mainly composed of quartz wafers and metal electrodes. Quartz wafers are usually made of quartz crystal, which undergoes mechanical deformation under the action of an electric field, and this mechanical deformation creates an electric charge that forms a resonant circuit.
How it works:
1. Mechanical vibration: When the voltage is applied to the quartz wafer, the quartz wafer produces small mechanical vibration due to the piezoelectric effect.
2. Resonant circuit: The charge generated by this mechanical vibration makes the quartz wafer a resonant circuit, and the resonant frequency is determined by the physical size of the quartz wafer.
3. Stable oscillation: The quartz wafer oscillates stably at the resonant frequency, providing a very accurate frequency signal.
Crystal oscillators play an important role in electronic devices, mainly in the following aspects:
1. Provide clock signals: Crystal oscillators are often used as clock sources to provide accurate clock signals for microprocessors, microcontrollers, etc., so that they can perform tasks according to precise time series.
2. Stable frequency: Due to the high stability of the crystal oscillator, it can provide very accurate frequency signals, which can be used in various occasions that require accurate timing, such as communication equipment, computers, etc.
3. Frequency synthesis: The crystal oscillator can be combined with other electronic components to generate signals of other frequencies through frequency synthesis to meet the needs of different electronic devices.
There is no positive or negative pole for the crystal oscillator itself, as it is a passively oscillating element. On the pins of the crystal oscillator, there are usually two pins, one is the input pin (in, which is generally used to connect to the input of the circuit), and the other is the output pin (out, which is generally used to connect to the output of the circuit). In addition to this, there is a ground pin (GND) that is used to connect to the ground of the circuit.
Unlike some active components (such as batteries, power supplies, etc.), crystal oscillators do not generate current themselves, but oscillate resonantly under external voltage excitation.
There are some important factors to consider when choosing a crystal oscillator:
1. Frequency: Select the frequency that matches the application requirements. The frequency of a crystal oscillator is usually measured in MHz (megahertz).
2. Accuracy: Different crystal oscillators have different frequency accuracy. For some applications that require high frequency accuracy, a crystal oscillator with higher accuracy needs to be selected.
3. Stability: Stability refers to the range of variation of crystal oscillator frequency. For equipment that needs to operate stably for a long time, it is necessary to choose a crystal oscillator with good stability.
4. Working temperature range: Different crystal oscillators have different working temperature ranges, and the appropriate crystal oscillator should be selected according to the actual working environment.
As a common electronic component, crystal oscillators play a key role in electronic devices, providing accurate clock signals and stable frequencies. Its working principle is based on the piezoelectric effect and the generation of resonant circuits of quartz wafers, which enables it to be widely used in different fields. It is hoped that through the analysis of this article, readers can have a more comprehensive understanding of the structure, function and principle of crystal oscillator, and provide a more solid foundation for electronic design.