Toshiba 23HL85 Circuit Diagrams page 5

1. Video Controller Unit & Display Data Conversion Unit
The video controller unit receives the video signals inputted through the tuner, AV port (VIDEO1, VIDEO2), and
converts them into an ITU656 signal through the microcomputer (VCTI) combined with the video decoder that
integrates various functions in one chip.
Either the analog RGB(FLI2300) signal or PC RGB signal is selected by the switching IC and inputted to a scaler
(GM2221), which is sent to the LCD module after being modified to an LVDS signal through the integrated LVDS IC.
VCTi is the main microprocessor that handles video signal processing and sound signal processing.
It also manages the RF signals received from the tuner.
The scaler can control timing to fit into the LCD panel, and can also control the size and position of the input
signal.
2. Power Supply Unit
The power supply unit provides 5V, 15V and 33V DC power to the Mainboard.
The 33V is directly used for the tuner.
15V power is directly used by the sound amplifier IC and is also used to generate 5V and 3.3V power through the
Step-Down DC/DC Converter. 5V power is converted to 3.3V and 1.8V power through the regulator, which in turn
supplies electrical power for ICs such as VCTI and scaler.
* The information contained in this section subjects to model.
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