The Function of Automobile Electronic Crystal Oscillator

With the continuous improvement of automobile performance, intelligence and safety factor, more and more data need to be processed by automobile CPU. Any complex instruction of CPU can not be realized without quartz crystal resonators and oscillators to provide stable and accurate clock signal source as a guide. 

quartz crystal resonators and oscillators plays an important role in automotive electronics：

Safety control system: engine control, steering by wire system, transmission, airbag, anti lock braking system, tire pressure detection system, electric power system, etc..

Data information system: car audio, vehicle navigation system, data bus system, video monitoring system, reversing radar, safety wire control system, etc..

Intelligent transportation system: automatic intelligent toll system, road traffic real-time data system, license plate automatic recognition system, highway intelligent system, intelligent transportation system, etc..

Automobile clock system: time display, timer, instrument panel, remote control door lock, remote control key, automobile air conditioner, automatic window control, automatic lamp, automobile anti-theft system, etc..

Below are the common frequencies and dimensions of the crystals used in a car:

TCXO, SMD3225 (e.g. for vehicle GPS navigation)

Common quartz crystal resonators and oscillators for Bluetooth and WiFi in vehicle: SMD 3225 26MHz or SMD 3225 16mhz is recommended, with a precision of at least ± 10ppm. 

Make sure that the connection and data transmission are normal without dropping the line.

Quartz crystal resonators and oscillators for time display:

The chip quartz crystal resonators and oscillators is 32.768KHz,  and the precision is ± 10ppm to ± 20ppm.

For the sake of stability, most of the schemes have been changed to SMD quartz crystal resonators and oscillators, such as SMD3225 27MHz, SMD3225 24MHz, SMD3225 26MHz, 32.768KHz.

The main function of quartz crystal resonators and oscillators 32.768KHz is responsible for time display, so it is widely used, such as meter, speedometer, electronic road meter, battery management unit, car radio, video and audio player, etc. Some high-end vehicle recorders use active quartz crystal resonators and oscillators, such as OSC3225, which is responsible for display function, 27MHz, 3.3V ± 10ppm.

Generally speaking, wide temperature range is applied in automobile grade. 

In the working temperature range of - 40 ~ + 85 ℃ or - 40-105 ℃, the quartz crystal resonators and oscillators needs to have normal working performance. It needs to be explained here:not all quartz crystal resonators and oscillators on cars are strictly required to be car standard level. For example, electronic devices such as car audio and dash cam have no strict requirements on the working temperature range of quartz crystal resonators and oscillators. However, different parts of the engine, the working temperature must meet - 40-125 ℃ or even - 40-150 ℃.