Crystal oscillators have a piezoelectric effect, which means that when a voltage is applied to the two poles of the chip, the crystal will deform. Conversely, if an external force causes the chip to deform, the metal plates on both poles will generate voltage. If an appropriate alternating voltage is applied to the chip, resonance will occur (the resonance frequency is related to the inclination angle of the quartz slope, and the frequency is constant). Crystal oscillators utilize a type of crystal that can convert electrical and mechanical energy into each other, and operate in a resonant state to provide stable and accurate single frequency oscillations. Under normal working conditions, the absolute accuracy of a regular crystal oscillator frequency can reach 50 parts per million. By utilizing this feature, crystal oscillators can provide relatively stable pulses and are widely used in clock circuits of microchips. The chips are mostly made of quartz semiconductor materials, and the outer shell is enclosed in metal.

The main application areas and frequency points of crystal oscillators

1、 Computer peripherals and electronic accessories

Main board: zhi14.318MHz, dao24.576, 25MHz, 27MHz, 32.768KHZ

Display: 8M/14.31818MHZ, 12.000MHZ, 24.000MHZ, 28.224MHZ

Hard disk: 23.040MHz, 28.224MHz

Optical drive: 33.8688MHz, 16.9344MHz, 18.432MHz

Keyboard: 6.000MHz

Mouse: 6.000MHz, 12.000MHz, 24.000MHz,

Camera: 12.000MHz

Bluetooth: 16.000MHz

Wireless WIFI: 25.000MHz, 2.5G/3G (40.000MHz, 44.000MHz)

Network transmission ADSL: 12.288MHz, 35.328MHz, 50.000MHz

The crystal oscillator on the motherboard is mainly divided into:

Crystal oscillator connected chip frequency clock Crystal oscillator clock chip 14.318MHz

Real time crystal oscillator South Bridge 32.768KHz

KBC 32.768KHz

Network card crystal oscillator network card chip 25.000MHz

Sound card crystal oscillator sound card chip 24.576MHz

Graphics card crystal oscillator graphics card chip 27MHz

Card reader crystal oscillator card reader chip 12MHz

The most important crystal oscillators on the motherboard are real-time crystal oscillators and clock crystal oscillators. Real time crystal oscillators provide oscillation frequency to Nanqiao, and almost all frequencies on the motherboard are based on clock crystal oscillators. If they damage the motherboard and cannot function properly.

The function of crystal oscillator: It forms an oscillation circuit with clock chips, sound card chips, network card chips, graphics cards, and other chips, which is the most important source of clock signal generation on the entire board.

2、 In terms of application communication

Fixed line telephone: 3.579545MHz

Cordless phone: 10.250MHz, 10.245MHz, 10.240MHz, 10.100MHz, 13.824MHz, 32.768KHz

Xiaolingtong: 19.2MHz

Mobile MTK solution TCXO: 27.000MHz, 24.000MHz, 26.000MHz

Wireless Bluetooth, GPS, RF (2.4G) car reverse radar, navigation: 16.000MHz, 12.000MHz, 26.000MHz

Interphone: 21.400MHz, 21.7000MHz

3、 Consumer electronics

Television: 4.433619MHz, 3.579545MHz, 12.000MHz.

DVD: 16.9344MHz, 27.000MHz.

Amplifiers: 4.500MHz, 7.200MHz, 12.288MHz.

Audio: 4.500MHz, 7.200MHz.

Set top box: 27.000MHz, 13.500MHz, 54.000MHz.

Remote control: 455E, 4.000, MHz, 32.768KHz.

Air conditioning: 4.194304MHz, 4.000MHz.

Small household appliances (kitchen type, etc.): 4.000KHz, 6.000MHz, 4.19430MHz, 32.768KHz.

Toy and gaming (remote control)/game console: 6.000MHz, 27.145MHz, 27.125MHz, 49.860MHz, 12.000MHz, 24.000MHz, 10.000MHz, 8.000MHz, 48.000MHz.

PMP, MP4: 27.000MHz, 12.000MHz, 24.576MHz.

Camera: 27.000MHz, 54.000MHz, 36.000MHz.

4、 Industrial automation, intelligence, and industrial control

Banking and financial systems/encrypted dogs/tax control systems/remote meter reading systems/testing instruments/ultrasonic waves:

50.000MHz, 3.579545MHz, 48.000MHz, 4.000MHz, 12.000MHz, 50.000MHz, 10.000MHz, 8.000MHz, 6.000MHz.

Security category: 13.560MHz, 24.000MHz, 12.270MHz

Medical instruments: instruments, micrometers, calipers, depth sensors, etc

Automotive electronics: oil control system/remote control/GPS/reverse radar/testing tire pressure/in car audio, etc. It is also applied to access control systems, video phones/intercom doors, intelligent control systems in residential areas, and health function products (blood pressure monitors, electronic scales, massage machines, etc.)

The application of active and passive crystal oscillator frequency

Optical transceiver:

25MHZ (49s for passive and 7050 for active), 65.536MHZ, 74.25MHZ, 80MHZ, 85MHZ, 100MHZ, 120MHZ, 125MHZ, 148.5MHZ, 150MHZ, 200MHZ

Audio Digital Effector

12.288MHz, 16.384MHz, 8MHz, 24MHz

Security (camera, alarm)

32.768KHZ, 24MHZ, 25MHZ, 27MHZ, 37.125MHZ, 45MHZ, 48MHZ, 50MHZ, 54MHZ, 74.25MHZ, 100MHZ, 108MHZ, 125MHZ

Bluetooth earphones

16MHZ, 26MHZ, 32.768KHZ

In car (front and rear cameras - navigation)

27MHZ * 19.2MH

Walkie talkie

19.2MHZ (temperature compensation), 24MHZ, 26MHZ (temperature compensation)

clock

32.768KHZ

Embedded design

7.3728MHZ, 12MHZ, 24MHZ, 24.576MHZ, 25MHZ, 27MHZ, 14.31818, 48MHZ, 32.768KHZ

mobile phone

32.768KHZ 26MHZ