Part Number: OM8378
Function: TV signal processor-Closed Caption decoder
Package: DIP 64 Pin Type
Manufacturer: Philips Semiconductors
The OM8373 and OM8378 combine the functions of a video processor together with a µ-Controller and US Closed Caption decoder. The ICs are intended to be used in economy television receivers with 110° picture tubes. The ICs have supply voltages of 8 V and 3.3 V and they are mounted in a SDIP-64 envelope. The features are given in the following feature list.
1. Vision IF circuit suitable for negative modulation with alignment-free PLL demodulator
2. Internal (switchable) time-constant for the IF-AGC circuit
3. The mono intercarrier sound circuit has a selective FM-PLL demodulator which can be switched to the different FM sound frequencies (4.5/5.5/6.0/6.5 MHz). The quality of this system is such that the external band-pass filters can be omitted.
4. Source selection between the ‘internal’ CVBS and an external CVBS or Y/C signal
A TV signal processor, including a Closed Caption (CC) decoder, is a crucial component in modern television sets and video equipment. The Closed Caption decoder is responsible for extracting and displaying closed captions, which are text-based subtitles or captions that provide a transcript of the audio content on the screen.
1. Reception of TV Signal: The TV signal processor receives the incoming television signal, which includes both the audio and video components. This signal can come from various sources, including cable or satellite providers, over-the-air broadcasts, or external devices like DVD players and gaming consoles.
2. Separation of Video and Audio: The processor separates the video and audio components of the incoming signal. The video component is sent to the TV display, while the audio is routed to the TV’s audio system.
3. Closed Caption Data Extraction: Within the audio and video signal, there is embedded data related to the closed captions. This data is encoded using a standard protocol, such as CEA-608 or CEA-708 for North American television broadcasts. The Closed Caption decoder within the TV signal processor extracts this data.