In more than ten years ago, packaging and size of crystal can be full size (20mm*12mm), now seems indeed a little big. A small size has been the development direction of the crystal manufacturers. So many years, has not changed. In the aspect of crystal miniaturization, whether it is the United States, Europe, or China, behind the Japanese. Like all other components of electronic products, product designers always hope that the oscillator has the advantage of smaller, faster, and cheaper. With the intelligent mobile phone and communication equipment such as network and mobile applications rapidly, terminal application requirements limit close to the oscillator performance range, huge market demand closed factories must improve the production process to the crystal in order to keep up with this requirement. So far, including Taiwan Hongxing, has begun to strongly recommend 3.2 * 2.5mm for mobile phone Bluetooth headset and other special ultra small size crystal products. The quartz crystal and the crystal oscillator suppliers accomplish the quartz crystal oscillator, crystal oscillator, VCXO and TCXO to reduce size of the current level, which was once thought to be impossible, especially in the absence of performance or increase the cost of the premise. More and more quartz crystal devices are assembled each year, the average selling price of mature products continues to decline.
Well, when it comes to application crystal in the television field mainly includes the following areas:
1, active crystal micro processing circuit applications
The function of the television micro processing circuit is to receive the remote control command signal, to process the command signal, and to control the working status of the television set. A clock signal is needed in the process of processing the command signal, which is used to control the timing of the operation of the micro processor. The clock signal is generated by a quartz crystal oscillator circuit. The common resonant frequency of the micro processing circuit using crystal oscillator are 10MHz, 12MHz, 8MHz, 1MHz, 4MHz, 4MHz crystal is most widely used.
2, the application for the ceramic crystal oscillation circuit
In order to display the grating, the television is provided with a line scanning circuit. Line scan circuit from the main line, line drive output oscillation: three unit, including the task of generating 15625Hz oscillation circuit frequency signal, and then promote the amplification, boost rectifier and line scan, the light emitting tube. According to the television line scanning of different formats, commonly used to line oscillator circuit resonant frequency of 500kHz and 503.5kHz ceramic crystal.
3, the sound used crystal oscillation circuit
In common to the resonant frequency of 500kHz ceramic crystal, but not in line with the sound circuit 500kHz crystal oscillator circuit 500kHz crystal GM, because the two are not the same performance. Second TV Sound IF signals with different formats can be 5.5MHz, 6.OMHz, 6.5MHz etc. in order to share a frequency, audio processing circuit audio signals of different frequencies, often set up a 500kHz signal oscillation circuit, so the use of electronic shield addition and subtraction technology to 5.5MHz and 6.5MHz into the 6.OMHz signal, sound signal so TV sound circuit only 6.OMHz.
4, color subcarrier circuit using quartz crystal
TV work in order to restore the image of color, there must be a sub carrier 4.43MHz, in order to demodulation of the reception signal in the color signal, the TV set to reproduce the color image. The subcarrier is generated by the composition of quartz crystal oscillation circuit. The PAL system uses the resonant frequency of 4.43MHz quartz crystal.
5, the remote control clock oscillator
The work of the remote controller needs a clock signal, the clock signal frequency division, coding, emission, can be turned into an infrared command signal, can command and control the working state of the tv. The clock signal is generated by a crystal oscillator circuit. Remote control the resonance frequency of 455kHz or 480kHz ceramic crystal.