LG 42LH90 Manual page 42

42LH90 LED Backlight Controls (Block Diagram)
42LH90 LED Backlight Controls (Block Diagram)
CN3 Controls 4 Boards
Each board controls 2 rows
of 4 Blocks.
Total 8 Blocks
INVERTER
CN306
Pulling CN306 will place all
M2-M4
CN3
CN4
M1-M3
24V
INV-ON CN1
There are two
DC to DC
Manipulated by:
converters
Video Content
(27.6V) for
Intelligent Sensor
each plug
Customer's Menu
CN3/CN4
Backlight Setting
Called M1-M4
Backlight setting
determines the
Backlight brightness
Ceiling
(Pin 6)
3.46Vp/p
Dimming
(Pin 4)
3.48Vp/p
Control
Signals
(Pin 1)
3.54Vp/p
LEDs in full bright.
ON/OFF
(Inverter On/Off)
24V
P203
Error
VBR-B
PWM-DIM
PWR (Power On)
(Global Dimming)
DC Voltage
PWM-DIM
(Global Dimming)
To Panel
-5V, 3.3V, 16V, 26V and
CN5 CN4
Local
T-CON
LVDS 12V
T-CON develops
-5V, 3.3V, 16V,
26V for Panel
CN1 CN2
LVDS
12V
120Hz Backlight
Blanking Signal
SMPS
P3501
12V
STBY 5V,
24V
12V, 24V
STBY 5V
Inv On/Off
PWM-DIM
PWR
P201
P700
Error
ON/OFF
(Inverter On/Off)
Customer's Menu
Backlight Selection
Only affects P-DIM
Customer's Menu
Brightness Selection
MAIN BOARD
Only affects
Luminance information
42
CN4/CN5 carry
Video for Panel
Luminance Manipulated by
the Brightness Setting
CN4 Controls
Each board
Quad 12 Bit
controls 2 rows
LVDS Video
of 4 Blocks.
Total 8 Blocks
Quad 12 Bit
LVDS Video
LVDS
12V
12V
Switch
Q706
IC3502
Dimming
12V
Tur-Motion
IC801
XD Engine
Luminance
12 Bit
LVDS
Video
I100
Mstar
Chip
Intelligent Sensor
(Room Light Monitor)
Only affects P-DIM
Drive Signals for CN3 and
CN4 going to V1 through V64
(LED Blocks)
Freq: 120Hz
Bright
Drive
Signal
Medium
4 Boards
Dim
Drive
Signal
27.6V
8 LEDs
Per/block