How to choose a suitable crystal oscillator and how to judge the quality of the crystal oscillator

Guangzhou Jingsheng Electronic Technology Co., Ltd. has been focusing on the production and sales of high-end quartz crystal resonators and quartz crystal oscillators. The company has production and testing equipment imported from the United States, Japan and Germany, ultra-purified production environment, skilled technology and professional technical personnel. Through quality and service, we have obtained ISO9001 quality system certification and ISO14001 environmental system certification, and our products meet RoHS standards.

Products are widely used in security monitoring systems, intelligent equipment, car audio, car radio, car anti-theft alarm system, tablet computers, digital TV receivers, communication equipment, radio clocks, computers, electronic digital and other industry products. Since the establishment of the company, we have always adhered to the business philosophy of providing customers with the most professional product solutions and supporting chain resources and services, and win-win cooperation

As we all know, the role of a crystal oscillator is to provide the basic clock signal for the system. Often, a system shares a single crystal oscillator, making it easy for all parts to stay in sync. Some communication systems use different crystal oscillators for their fundamental frequency and radio frequency, which are kept synchronized by electronically adjusting the frequency.

1. Consideration of frequency stability.

One of the main characteristics of a crystal oscillator is its stability over the operating temperature, which is an important factor in determining the oscillator**. The design engineer carefully determines the actual needs of a particular application and then specifies the stability of the oscillator.

2. Output. Each output type has its own unique waveform characteristics and uses. Attention should be paid to the requirements of tri-state or complementary outputs. Symmetry, rise and fall times, and logic levels are also specified for some applications.

3. Phase noise and jitter.

The phase noise obtained in the frequency domain is a true measure of short-term stability. It can measure to within 1 Hz of the ** frequency and 1 MHz normally. The phase noise of the oscillator is improved at frequencies away from the center frequency.

Jitter is related to phase noise, but it is measured in the time domain. Jitter expressed in picoseconds can be measured with RMS or peak-to-peak.

Fourth, the influence of power supply and load.

The frequency stability of the oscillator is also affected by fluctuations in the supply voltage of the oscillator and fluctuations in the oscillator load. Choosing the right oscillator minimizes these effects. The designer should verify the performance of the oscillator at the recommended supply voltage tolerances and loads.

5. Crystal oscillator packaging.

Like other electronic components, clock oscillators are available in increasingly small packages. Small packages often have to compromise performance, output selection, and frequency selection.

6. Working environment.

The environment in which the oscillator will be used requires careful consideration. For example, high vibration or shock levels can cause problems for oscillators.

According to the above points, I believe it can help you choose the right crystal oscillator, because, like friends, crystal oscillators can only be together if they are in tune.

Electronic accessories, crystal oscillators, judge good or bad, do you know? The master will teach you to look at it.

Crystal oscillator, generally known as crystal resonator, is a kind of electromechanical device, which is made of quartz crystal with little electrical loss by precision cutting and grinding and electrode plating and welding leads. This crystal has a very important property, if it is electrified, it will produce mechanical oscillation, and conversely, if it is given mechanical force, it will produce electricity, this characteristic is called piezoelectric effect. They have a very important feature, their oscillation frequency is closely related to their shape, material, cutting direction, etc.

Because the chemical properties of quartz crystals are very stable, the coefficient of thermal expansion is often small, and its oscillation frequency is also very stable, because the control geometry can be very precise, therefore, its resonant frequency is also very accurate. According to the electromechanical effect of the quartz crystal, we can equate it to an electromagnetic oscillation loop, that is, a resonant loop. Their electromechanical effect is mechanical-electrical-mechanical-electric.

The resonant circuit consisting of inductance and capacitance is a continuous conversion of the electric field-magnetic field. The application in the circuit is actually to treat it as a high-Q electromagnetic resonance loop. Since the loss of quartz crystal is very small, that is, the q value is very high, it can produce a very stable oscillation when used as an oscillator, and a very stable and steep bandpass or bandstop curve can be obtained when used as a filter.

Crystal oscillator function: provide a stable clock signal for the normal operation of the single-chip microcomputer. Principle:

When an electric field is added to the two plates of the quartz crystal, the wafer will produce mechanical deformation, and the mechanical force applied to the plate will deform it, and the corresponding charge will be generated on the plate, which is called the piezoelectric effect. If an alternating voltage is applied to two plates, the wafer will be mechanically deformed**, and this machinery** will also produce an alternating electric field (relatively small), but when the frequency of the applied alternating voltage is equal to the intrinsic frequency of the wafer (determined by its shape and size), the amplitude of the mechanical vibration will intensify and the alternating electric field will be increased. It's called piezoelectric harmonics.

Resources.

Quartz crystal devices are components that accurately and stably generate a reference signal for radio waves.