BenQ XL2411T Product Service Manual page 50

from 1920x1080, combined with the critically proven integrated 8 bit triple-ADC and
patented Rapid-lock digital clock recovery system. It also support detect mode and
DPMS control.
3. MCU embedded in Scalar: Control unit, it controls all the functions of this interface board,
just like the OSD display setting, the adjustable items, adjusted data storage, the
external IIC communication, support DDC2Bi. .
4. EEPROM: We use 24C32 to store all the adjustable data, user settings and uses four
24C02 to store D-SUB, DVI and HDMIx2 data.
5. Flash-rom stores source code.
A-2) Control board introduction:
There are 6 keys for user's control which includes "Power", "Menu", "Up/Plus", "Down/Minus",
"Exit", and "Enter". The following descriptions are the introduction of these keys.
(1) Power key: to turn/off power of monitor
(2) "Menu" key: to enter OSD main menu.
(3) "ENTER" key: to enter sub-menus or select items.
(4) "EXIT" key: Exit OSD.
(5) "UP/Plus key: to select previous and to increase adjustment.
(6) "Down/Minus" key: to select next and to decrease adjustment.
(7) LED: It indicates the DPMS status of this LCD monitor; white light means DPMS on
(Normal operating condition). Amber light means DPMS off (Power Saving).
A-3) LED Driver Circuit Operation Theory
An high power DC-DC boost converter controller—MPS3397
MPS3397 is a high efficiency DC-DC controller that drives up to eight strings connected in parallel
configuration with multiple LEDs in each string connected in series.
MPS3397 provides four (4) LED current sense inputs in an "OR" configuration to improve backlight
reliability. This allows the backlight to remain functioning in the event that a string(s) is damaged
during normal operation
The IC provides an integrated circuit to balance the current flow through each LED string. It also
features a low standby current or the LED backlight system.
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