LG LB570D, LB570E BLOCK DIAGRAM

BLOCK DIAGRAM

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POWER CORD

15-pin D-SUB SIGNAL CABLE

POWER

SUPPLY

CONTROL PCB

INVERTER PCB

MAIN LOGIC

PCB

LCD MODULE

System Block Diagram

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BLOCK DIAGRAM FOR LB570D (570LE)

24bit

Video

Digital

Video Processor

MX88L284

R

G

B

HS/VS

Dot clock

System Controller

MC68HC05BD32

Power Connector

DC/D C

Converter

(L4973D5.1)

REG

REG

REG

REG

REG

Analog

Switch

+5V

+5V Module

I2C

Control

EEPROM

(24LC08B)

Link Connector

Panel Link

Transmit ter

( Sil 100 )

Control

Signal

TMDS

SDA/SCL

15PIN

3 ROW

D-SUB

PRE AMP+ ADC

+PLL

TDA8752B

8 BIT

8 BIT

8 BIT

H-sync

Clamp

Buffer

+24V GND

+5VST

+5VPLL

+3.3VD2

+3.3VD

+5V

+5V

+5VPLL

+5VANA

5VST

+3.3VD

+3.3VD

V-sync

ADDR

DA TA

10

16

/RD

/WR

MEMORY

2M Byte * 2

I2C

+3.3VD2

H-sync

V-sync

Control

Communication

8bit

DESCRIPTION OF BLOCK DIAGRAM FOR LB570D (570LE)

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1. Video Amp & PLL & A/D Converter Circuit

TDA8752 (U1) is one chip IC which it supports three function block of Video Amp, PLL and A/D converter.
Video signal (0.7Vp.p) clamped through C6, 7, 16 inputs to U18’s R, G, and B pins. The signal level is 0.7Vac
added 3Vdc. This signal is processed as a proper 8 bit digital signal for input of MX88L284 (U5) by U1’s
amplifying, phase locking, and A/D converting operation.
U1 generates clock and horizontal sync for MX88L284 (U5) with D-sub (J1)’s input horizontal sync signal.
MX88L284 (U5)’s clamp output makes U1 keep video signal’s black level constantly regardless of
various input video signals.

2. Macronix Circuit (Scaler chip)

The MX88L284 (U5) gets the video signal converted analog to digital from U1, and carries out four function
of image processing that interpolates input signal less than 1024x768 resolution to that of 1024x768 resolution,
displays one to one image without interpolation, mixes OSD(On Screen Display) signal by interfacing with
internal OSD IC, and controls two memories(U6, 7) as frame converter.
U5 outputs signals of HSYNC-OUT, VSYNC-OUT, DEN, CLKA-ODD, and each 8 bit R, G, B to transmitter
IC (U16).

3. Memory Circuit

2M byte SDRAM(U6, 7) is used as a frame converter for supporting up to 85 Hz frame rate and
controlled by MX88L284(U5).
The control signals are CKA, CLK, UDOM, LDOM, /WE, /CAS, /RAS, /CS, /BA.

4. Panel-Link Circuit

Panel link transmitter (U16) delivers digital signal to the receiver inside LCD module by method of abstraction.
The abstracted signals are pairs of TX0+-, TX1+-, TX2+-, TXC+- of which voltage swing is 0.5V each.
Its swing is similar to LVDS (Low Voltage Differential Signal).
Transmitter (U16) gets signals of HSYNC-OUT, VSYNC-OUT, DEN, CLKA-ODD from U5, and outputs TMDS
(Transition Minimized Differential Signal) through TX pins.
When PD pin’s input is low, transmitter goes to power down mode.

5. System Controller (Microprocessor) Circuit

1) Microprocessor (U4) distinguishes polarity and frequency by calculating horizontal and vertical sync input
from signal source.

2) Microprocessor (U4) carries out power control by sending power-down trigger signal to each IC.
U1, U5, U16, and U13 has PD(Power-down) pin which operates at active-low or high.
It also outputs signal to turn inverter on and off for lamp control.

3) Microprocessor (U4) communicates with EEPROM (U3), TDA8752 (U1), and MX88L284 (U5)
through IIC(2 lines) or 8 bit bus line. It makes all devices operated properly with communication channel.

4) Microprocessor (U4) let User adjust screen by each OSD function.

6. DC/ DC Converter

This circuit supplies DC power for each device needing DC voltage of+3.3VD, +3.3VD2, +5V, 5VPLL, and 5VST.
L4973D5.1(U13) , the DC/DC controller IC converts input 24Vdc into +5Vdc and +3.3Vdc with peripheral circuit
composed of Transformer (TRANS1), condensing components (ZD5, D6, C201, C26, C72, C73) and Regulators
(U17, U2, U24). 5VST is supplied for Microprocessor through regulators (U11, U22).
+5VMOD for LCD module power are switched by U12, switching FET, controlled by Microprocessor.

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BLOCK DIAGRAM FOR LB570E (570LS)

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DESCRIPTION OF BLOCK DIAGRAM FOR LB570E (570LS)

1. Video Amp & PLL & A/D Converter Circuit

TDA8752 (U1) is one chip IC which it supports three function block of Video Amp, PLL and A/D converter.
Video signal (0.7Vp.p) clamped through C6, 7, 16 inputs to U18’s R, G, and B pins. The signal level is 0.7Vac
added 3Vdc. This signal is processed as a proper 8 bit digital signal for input of MX88L284 (U5) by U1’s
amplifying, phase locking, and A/D converting operation.
U1 generates clock and horizontal sync for MX88L284 (U5) with D-sub (J1)’s input horizontal sync signal.
MX88L284 (U5)’s clamp output makes U1 keep video signal’s black level constantly regardless of
various input video signals.

2. Macronix Circuit (Scaler chip)

The MX88L284 (U5) gets the video signal converted analog to digital from U1, and carries out four function
of image processing that interpolates input signal less than 1024x768 resolution to that of 1024x768 resolution,
displays one to one image without interpolation, mixes OSD(On Screen Display) signal by interfacing with
internal OSD IC, and controls two memories(U6, 7) as frame converter.
U5 outputs signals of HSYNC-OUT, VSYNC-OUT, DEN, CLKA-ODD, and each 8 bit R, G, B to LCD module.

3. Memory Circuit

2M byte SDRAM(U6, 7) is used as a frame converter for supporting up to 85 Hz frame rate and
controlled by MX88L284(U5).
The control signals are CKA, CLK, UDOM, LDOM, /WE, /CAS, /RAS, /CS, /BA.

4. System Controller (Microprocessor) Circuit

1) Microprocessor (U4) distinguishes polarity and frequency by calculating horizontal and vertical sync input
from signal source.

2) Microprocessor (U4) carries out power control by sending power-down trigger signal to each IC.
U1, U5, and U13 has PD(Power-down) pin which operates at active-low or high.
It also outputs signal to turn inverter on and off for lamp control.

3) Microprocessor (U4) communicates with EEPROM (U3), TDA8752 (U1), and MX88L284 (U5)
through IIC(2 lines) or 8 bit bus line. It makes all devices operated properly with communication channel.

4) Microprocessor (U4) let User adjust screen by each OSD function.

5. DC/ DC Converter

This circuit supplies DC power for each device needing DC voltage of+3.3VD, +3.3VD2, +5V, 5VPLL, and 5VST.
L4973D5.1(U13) , the DC/DC controller IC converts input 24Vdc into +5Vdc and +3.3Vdc with peripheral circuit
composed of Transformer (TRANS1), condensing components (ZD5, D6, C201, C26, C72, C73) and Regulators
(U17, U2, U24). 5VST is supplied for Microprocessor through regulators (U10, U11, U22).
+3.3VMOD for LCD module power are switched by U12, switching FET, controlled by Microprocessor.