Acer X193HQ Series, Service Manual

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III. Circuit operation theory:
A.) THE MAIN BODY:
A-1.) Interface board block diagram:
(a) Circuit operations:
The scaling IC has OSD and auto detecting input timing functions. OSD offers
adjustable functions to the end-users. Auto detecting timing function can detect change
modes. It outputs the digital R-G-B data, pixel clock and control signal to TCON of the LCD
module. A MCU, build in scaling IC (Realtek2525LH), is responsible for the system
processing. There are two external storing units, one is 24C16 to store the OSD function
data and user preset timings.
(b) IC introduction:
1.) Realtek2525LH SCALER IC:
Realtek2545L series products are all-in-one LCD monitor controller with
analog (RGB), DVI and video inputs, supporting UXGA/
WXSGA+WXGA+/SXGA(optional),and integrate Realtek high performance
ADC,scaling engine,LVDS Tx,and so on.Moreover,all products are pin compatible in
QFN 48-pin package to save cost and make the design easier. The RTD also
includes an ITU656 video format input port with color space converter that makes it
an attractive solution for low cost MFM and TV applications. The output section
contains a 24-bit TTL output interface and a channel LVDS transmitter for direct
interfacing of commercially available LVDS LCD panel modules. In addition,
RTD2525LH embedded 16.5KSRAM dynamically stores OSD command and fonts,
compatible advanced color control features.