Ic Introduction; Ddc (Display Data Channel) Function; Rtd2023 Ic - BenQ Q7T4-FP71G Service Manual

Q7T4-FP71G LCD Monitor Service Guide
140MHz
D-SUB
(a) Circuit operation theory:
A basic operation theory for the interface board is to convert input signal into digital RGB .
Analog RGB signal is converted to digital signal through ADC. The microprocessor RTD2023
receives video data and optimizes the image automatically. It also supports 16 color from a 64k
palette bitmap OSD, and keypad controlling. The output data are sent to LCD module.
(b) IC introduction:
1.) DDC (Display Data Channel) function: We use DDC IC to support DDC/2B function. DDC
data is stored in 24C04(EEPROM). Those data related to LCD monitor specification. PC
can read them by "SDA" and "SCL" serial communication for I ² C communication for
DDC2B.
2.) RTD2023 IC: There are triple ADC, LVDS transmitter ,Scaling, and OSD functions in the
RTD2023 IC. Scaling IC is revolutionary scaling engine, capable of expanding any source
resolution to a highly uniform and sharp image, combined with the critically proven
integrated 8 bit triple-ADC and patented Rapid-lock digital clock recovery system. It also
RTD 2023
ADC
Confidential
Circuit Operation Theory
MTV312M
64(AJ)
IIC Keypad
Clock
Generator
XGA
1280×1024
LCM
2