Text preview for : Circuit Description.pdf part of Samsung monitor lcd samsung 540N_540B_740N_740B_740T_940B_940T_940N Monitor Lcd Samsung modelos:
540N
540B
740N
740B
740T
940B
940T
940N
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13 Circuit Descriptions
13 Circuit Descriptions
13-1 Overall Block Structure
13-1-1 Power Tree
Panel Operating Board
SE16/56AL Core Operation
SE16/56AL Interface Operation
0.6W Self-Loss
1. When the AD board is in DPMS state: 1.1 The IP has been designed so that it operates with a power consumption of less than 0.6W of. 1.2 The Scaler consumes power up to 27mA 1.3 The power to the panel is switched off 1.4 The MCU consumes power up to 23mA. --> The total current consumption to the DPMS is less then 60mA and the total power consumption is 0.6W + 5V*60mA = 0.9W so that the total power consumption is less than 1W. 2. When the AD board is operating normally: 2.1 The maximum power consumption of the panel lamps is described below (It may vary depending on the panel manufacturer) 17" : 4*(7.5mA*650mVrms)=4*4.9=19.6W 19: : 4*(7.5mA*720mVrms)=4*5.4=21.6W 2.2 The power consumption of the Panel Control board is as follows: 5V*720mA=3.6W 2.3 The power consumption of the Scaler is as follows: 3.3V*245mA + 1.8V*300mA = 1.35W 2.4 The power consumption of the MCU is as follows: 5V*44mA =0.22W
13-1
13 Circuit Descriptions
13-1-2 Main Board Parts
1. Inverter: A conversion device that converts DC rated voltage/current to high ones necessary for the panel lamp. 2. DC/DC(Regulator): General term for DC to DC converting devices. The IP board receives 5V and outputs 1.8 or 3.3V that is supplied to the scaler (SE56AWL). 3. Power MosFET: The IP board receives 5V and outputs a lower voltage in DPMS mode and supplies the whole 5V for the panel operating board in normal conditions. In that case, the switching of Power MosFET is controlled by Micom. 4. Scaler: Receives the digital TMDS and analog R,G,B signals and convert them to proper resolutions using up- or down- scaling that are transferred to the panel in the LDVS formats. 5. Crystal(Oscillator): Use one 24MHz oscillator externally to supply power to both MCU and Scaler at the same time.
6. MCU & EEPROM: I2C is a two-way serial bus of two lines that supports communications across the integrated circuits as well as between MCU, Scaler and EEPROM. In particular, MCU and Scaler (SE56AWL) use the DDR direct bus for mutual communications, which is an effective, speedy system because it allows 4 additional address/data lines compared to the old serial systems. 7. Function Key: A certain keystroke generates a certain electrical potential, which is transferred into ADC input port of the MCU and then converted to a digital value by the A/D converter of the chip. The digital value (data) is a clue to which key is entered. In practical, the voltage levels are set as below.
13-2
13 Circuit Descriptions
13-1-3 IP BOARD BLOCK(POWER) Parts
13-1-4 IP BOARD BLOCK( INVERTER ) Parts
I BO A RD P B LO C K ( I V ERT ER ) N
I V ERT ER PA RT N
D C I put nput n + 1 dc 13V
POWER DC INPUT
Lamp FULL BRIDGE CIRCUIT Lamp Lamp Lamp
+ 5V d 5V dc A D I + 3. dc M . 3V 3 BD I + 4. dc M . 5V
ON/OFF DIM INPUT
INVERTER CONTROL IC DRIVER IC
FEED BACK CIRCUIT PROTECTION CIRCUIT
C O N T RO L PA RT
13-3
13 Circuit Descriptions
13-1-5 IP BOARD ( inverter ) PROTECTION Parts
BIZET INVERTER CONTROLER FAN7310 have 2-way of the PROTECTION MODE. 1. OVP[Over Voltage Protection] : If the Voltage of the series capacitors C10 & C15 is over the 2.0V, the Inverter latched-off.[See the Picture1] 2. OLP[Over Load Protection] : If the inverter output harness is opened(No-output current), the base of the Q1 turns on and chage the C9 ovter 2V and then, the Inverter latchedoff[See the Picture2]
Figure 1.
Figure 2. 13-4
13 Circuit Descriptions
13-2 Trouble Shooting
13-2-1 IP BOARD(Power)
Power On
No Check fuse
Change FUSE
Yes
3 pin of FDM0565R Vcc system in normal: HIGH
No
Check the Vcc system
Yes
1 pin of FDM0565R Check the drain system Normal: Switching
No
Check the main switching
Yes
Check the protection system
No
Check the output current
No
Check the feedback system
Yes Check others Harness, Inlet
13-5
13 Circuit Descriptions
13-2-1 IP BOARD(Inverter)
Power On
No
Check the power system
Yes
1 and 2 pins of FDM0565R Check Protection Normal:0.6V~0.8V Yes
No
Check the IC drive Check MOSFET
1 and 2 pins of FDM0565R Check Protection Normal:0.6V~0.8V
No
Check the OVP and OLR circuits
Yes
Check any dimming circuit
No Check the output current
No
Check the feedback system
Yes
Check others
13-6
13 Circuit Descriptions
13-3 IP BOARD(Power) Schematic Diagrams
13-7
13 Circuit Descriptions
13-4 IP BOARD(Inverter) Schematic Diagrams
13-8