The LA7687A is a popular integrated circuit (IC) used in television sets for horizontal deflection and synchronization.
Part Number: LA7687, LA7687A
Function: TV Horizontal Synthesizer Circuit
Manufacturer: Sanyo
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Description
The TV Horizontal Synthesizer IC, also known as the TV horizontal oscillator IC or horizontal deflection IC, is an integrated circuit used in television sets and monitors to generate the horizontal synchronization signals for scanning the electron beam across the screen horizontally.
The horizontal synchronization signal is crucial for synchronizing the scanning of the electron beam as it moves across the screen from left to right during each horizontal line of the display. The horizontal oscillator IC generates the required timing signals, including the horizontal sync pulse, flyback pulse, and other control signals necessary for proper horizontal scanning.
Features:
1. Horizontal synchronization: The IC generates the horizontal synchronization signals required for proper scanning of the electron beam across the screen.
2. Oscillation frequency control: The IC allows adjustment of the horizontal scanning frequency to control the number of horizontal lines displayed per second.
3. Drive output: The LA7687A provides a drive output for the horizontal deflection circuit, which drives the horizontal deflection coil or transformer responsible for moving the electron beam horizontally across the screen.
4. Protection features: The IC incorporates protection mechanisms such as overvoltage protection, overcurrent protection, and thermal shutdown to safeguard against potential damage or malfunctions.
5. Integrated circuitry: The LA7687 integrates various components, including a horizontal output transistor (HOT), to simplify the design and reduce the external circuitry required.