Introduction to crystals

The author:admin Number of visits: Date:2020-12-28 13:48

1. What is crystal oscillator

Crystal oscillator is the abbreviation of what we often call quartz crystal oscillator.So what exactly is a crystal oscillator?So first we need to know what a quartz crystal is.Quartz crystal, commonly known as crystal, is not only a better optical material, but also an important piezoelectric material. It will have different crystal structures and achieve different effects under different temperature conditions, so that we can make a variety of different piezoelectric crystal components.

Now let's say what is the quartz crystal oscillator (abbreviation: crystal oscillator), in fact, it refers to the slice cut from a quartz crystal according to a certain azimuth Angle (abbreviation: chip), and IC together for packaging, the crystal components of the oscillator circuit is called the quartz crystal oscillator.In fact, it is a kind of electromechanical components that can convert electrical energy into mechanical energy and mechanical energy into electrical energy.

Quartz crystal oscillator, referred to as quartz crystal or crystal, crystal oscillator, etc.;The products are usually packaged in metal cases, but also in glass, ceramic or plastic cases.

The crystal oscillator is generally divided into active crystal oscillator and passive crystal oscillator.The active Oscillator is called the Oscillator, and the passive Oscillator is called the Crystal.

2. What is the working principle of crystal oscillator

It works like a guitar string, you set a lower chord will vibrate AT a fixed frequency, crystal oscillator is also the principle, just replace string with crystals, because the crystals have piezoelectric effect, when you're a pulse voltage for crystal, crystal will vibrate AT a fixed frequency (by changing the crystal shape change frequency, it is often said the AT cutting, BT cutting), and crystal vibration or shock and converts mechanical energy into electrical energy, so crystals is converts electrical energy into mechanical energy, and the process of mechanical energy into electrical energy, the crystal is a fixed frequency output pulses of electricity.

3. Cutting type of crystal

Crystals need to be cut at a certain Angle before they can be used. If the cutting type is slightly wrong, then many crystals cut out will not meet the standard we need, so the cutting type is also very important.So far, there are three cutting methods for the crystal: AT cutting, BT cutting and CT cutting.Let's briefly analyze the two methods below.

(1) cut the AT:

The AT-cut temperature curve is relatively smooth and easy to process, so most of the crystals on the market now use AT-cut.

(2) the BT cut:

BT cutting relative to AT cutting temperature characteristics are not good, but the wafer is thicker.When the fundamental frequency of the crystals is very high, and the products do not require very high temperature characteristics, BT cutting is easier to process than AT cutting, and the reliability of the products will be much better.

The above is the preliminary understanding of crystal oscillator, there will be more knowledge to upload in the future, I hope you continue to pay attention to.