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5.5.3.2 Buttons Control
- Button “Power” in middle of bezel connects to U108 #9 through R156, via CN104#8.
- Button “UP” “DOWN ““MENU” “ENTER” in the bottom of bezel connects to U108 #21,#22,#14 through
R189,R188,R159 via CN104 #1, #2,#3
- U106 is an EEPROM IC which memory OSD setting and save the value adjusted by user.
- LED Indicator on Front Bezel
a. When press button “power”, U108 #48 sends out a low potential, via R165, flow to CN104 #7 on keypad,
LED Green ON.
b. When in “Suspend” mode, U108 #1 sends out a low potential, via R168, flows to CN104 #5 on keypad,
LED Amber ON.
5.5.3.3 REALTEK CHIP U105 (scaler
),U108(MCU)
- U105 (RTD2545LH ) #21~#28 output 8 bit even LVDS digital data to panel control circuit through CN103.
- U106 (RTD2545LH) #29~#38 output 8 bit odd LVDS digital data to panel control circuit through CN103.
- U108 (RTD2120_LQFP48 ) #44 outputs Brightness “PWM” signals to control CCFL brightness.
- U108 (RTD2120_LQFP48 ) #39 output PANELPOWER ON/OFF to make Q104 conducted, and then make
Q101 conducted, +5V flow to CN103#1~#3 as Panel VDD .
- U108 (RTD2120_LQFP48) #20 output CCFL_ON/OFF ”H” and “L” potential to control Inverter on/off.
Please refer to RTD2120_LQFP48 Pin Assignments table in page
5.5.3.4 Regulator Circuit
- +5V is from switching mode power supply for Panel used.
- +3.3V generates from +5V through C101 filtering and U101 which is output +3.3V LDO for U102, U108
and U202 used.
- +1.8V generates from +3.3V through C138 filtering and U102 which is output +1.8V LDO.
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