Research And Design Of Online Testing System Of Quartz Crystal Oscillator

Quartz crystal oscillator is an electronic component which is used as a frequency standard,It can make frequency stable and achieve the function of frequency selection and detection,quartz crystal oscillators are widely used in various types of electronic systems,equipment and instruments such as wireless telephones,mobile communications,radio,television,satellite and remote communication,electronic watches and all kinds of digital instruments.With the application of quartz crystal is not only daily consumer electronics,but also it has a very important role in the development of space technology and military technology,the quality of quartz crystal oscillators are also getting higher and higher,toward the high stability,high accuracy,high frequency direction,the requirements of crystal oscillator in the power consumption,temperature range,working voltage and technical index are more demanding,so it also put forward a higher requirement in the test system of the quartz crystal oscillator,at present,many advanced testing equipment are imported from abroad,but they are very expensive,therefore,it require us to develop a equipment which is suitable for our own test.Through the model analysis and electric parameter analysis of the quartz crystal oscillator and the production flow and the test method of the electric parameters of the quartz crystal oscillator,the host computer is designed.an online testing system is designed with the upper computer and the measurement and control system as the lower computer,the measurement system which is based on the zero phase technique in a ?-network,using the DDS sweep signal source as the signal source of the testing network and using the IEC444 Crystal oscillator test as the test standard test and parameter calculation method,AD9852 and AD8302 as the core,measures the electrical parameters of quartz crystal oscillators;The control system and servo motor as the production automation control program controls online testing of quartz crystal oscillators and classifies the results,achieving the three production line operation—production?test and classification of the results.This system is designed for the crystal type which is produced in a company in Jingmen Hubei,The measurement range of crystal is 1-50 MHz,the maximum number of measurable parameters are 10,including series and parallel resonant frequency,series resonant frequency,load resonant frequency,resonant resistance,dynamic parameters,static capacitance.This system can choose different test templates according to different batches,automatically manage the testing process,analyze and judge test results,deal with the qualified and unqualified products,improve production efficiency.Finally,by testing and analyzing the influence of distributed capacitance,inductance of the PI network on testing,the accuracy of the testing resonance frequency is down to + 2ppm,it is proved that the system has good stability and practicability.