TV crystal category

Crystal Ceramic Surface 3225G (3.2*2.5mm) 8.000MHZ 10PFK

Crystal oscillators are among the most commonly used electronic components in various circuits, especially in digital devices, communication systems, wireless routers, remote controls, and televisions. This article explores five key types of crystal oscillators used in TV circuits, explaining their roles and applications in detail.

1. Ceramic Crystal Oscillators for Remote Control Applications

Remote controls rely on a clock signal to process, encode, and transmit commands via infrared signals. This clock is generated by a ceramic crystal oscillator, typically operating at frequencies like 455 kHz or 480 kHz. Common models include CSB480A, CSB480A1, and similar variants. These oscillators ensure accurate timing and reliable signal transmission between the remote and the TV.

2. Quartz Crystal Oscillators for Microprocessor Circuits

The microprocessor in a television handles command signals from the remote control and manages the TV’s operations. To function properly, it requires a stable clock signal, which is produced by a quartz crystal oscillator. Typical frequencies used in these circuits are 1 MHz, 4 MHz, 8 MHz, 10 MHz, 12 MHz, with 4 MHz being the most common. These oscillators provide the necessary timing accuracy for smooth processing and system operation.

3. Quartz Crystal Oscillators for Color Subcarrier Circuits

To display color images, TVs use a subcarrier signal at 4.43 MHz, which is essential for demodulating color information in the received signal. This frequency is generated using a quartz crystal oscillator, commonly found in PAL systems. Popular models include 4.43X, A74994, FQC4.433619, and others. For NTSC systems, the subcarrier is usually 3.58 MHz or 8.86 MHz, depending on the region.

4. Ceramic Crystal Oscillators for Line Oscillation Circuits

The line oscillation circuit is responsible for generating the horizontal scanning signal needed to create the TV screen's raster. This circuit produces a 15,625 Hz signal that drives the electron beam across the screen. Ceramic crystals with frequencies of 500 kHz or 503.5 kHz are often used. Common models include 500F2, 503A16, CSB500F2, and many others. These oscillators ensure accurate synchronization of the image display.

5. Ceramic Crystal Oscillators for Audio Circuits

In TV audio systems, a 500 kHz crystal oscillator is frequently used to generate a reference signal that helps convert different intermediate frequencies (such as 5.5 MHz or 6.5 MHz) into a common 6 MHz signal. This allows the audio circuit to process only the relevant frequency. Models like CRB500E and 2500K are widely used, but it's important to note that these are not interchangeable with those used in line oscillation circuits due to differing performance requirements.