Acer G225HQ Service Manual page 57

III. Circuit Implementations:
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 (Realtek2545LH), 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.) Realtek2555LH SCALER IC:
Realtek2555LH series products are all-in-one LCD monitor controller with analog (RGB), DVI and video inputs,
supporting 1920x1080@60Hz ,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,
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