Samsung ppm42s2x service manual

PLASMA DISPLAY TV

Chassis : D53A Model: PPM42S2X/XAA

PLASMA DIAPLAY TV CONTENTS

Precautions

Reference Information

Specifications

Alignment and Adjustments

Circuit Operation Description

Troubleshooting

Exploded View and Parts List

Electric Parts List

Handling Description

Glossary

Wiring Diagram

Schematic Diagrams

10.

11.

12.

ELECTRONICS

Printed in Korea

AA82-

1. Precautions

1-1 Safety Precautions

1. Be sure that all of the built-in protective devices are replaced. Restore any missing protective shields.

2. When reinstalling the chassis and its assemblies, be sure to restore all protective devices, including: nonmetallic control knobs and compartment covers.

3. Make sure that there are no cabinet openings through which people—particularly children—might insert fingers and contact dangerous voltages. Such openings include the spacing between fornt cabinet and back cabinet, excessively wide cabinet

ventilation slots, and improperly fitted back

covers.

4. Leakage Current Hot Check (Figure 1-1): Warning: Do not use an isolation transformer during this test. Use a leakagecurrent tester or a metering system that complies with American National Standards Institute (ANSI C101.1, Leakage Current for Appliances), and Underwriters Laboratories (UL Publication UL1950.5.2).

5. With the unit completely reassembled, plug the AC line cord directly into the power outlet. With the unit’s AC switch first in the ON position and then OFF, measure the current between a known earth ground (metal water pipe, conduit, etc.) and all exposed metal parts, including: antennas, handle brackets, metal cabinets, screwheads and control shafts. The current measured should not exceed 3.5 milliamp. Reverse the powerplug prongs in the AC outlet and repeat the test.

Fig. 1-1 AC Leakage Test

6. Antenna Cold Check: With the unit’s AC plug disconnected from the AC source, connect an electrical jumper across the two AC prongs. Connect one lead of the ohmmeter to an AC prong. Connect the other lead to the coaxial connector.

7. High Voltage Limits: High voltage must be measured each time servicing is done on the B+, horizontal deflection

or high voltage circuits.

Precautions

Samsung Electronics 1-1

LEAKAGE CURRENT

TESTER

DEVICE UNDER

TEST

TEST ALL

EXPOSED METAL

SURFACES

2-WIRE CORD

ALSO TEST WITH

PLUG REVERSED

(USING AC ADAPTER

PLUG AS REQUIRED)

EARTH

GROUND

(READING SHOULD

NOT BE ABOVE

0.5mA)

Follow these safety, servicing and ESD precautions to prevent damage and protect against potential hazards such as electrical shock and X-rays.

1-2 Safety Precautions (Continued)

8. High voltage is maintained within specified limits by close-tolerance, safety-related components and adjustments. If the high voltage exceeds the specified limits, check each of the special components.

9. Design Alteration Warning: Never alter or add to the mechanical or electrical design of this unit. Example: Do not add auxiliary audio or video connectors. Such alterations might create a safety hazard. Also, any design changes or additions will void the manufacturer’s warranty.

10. Hot Chassis Warning: Some TV receiver chassis are electrically connected directly to one conductor of the AC power cord. If an isolation transformer is not used, these units may be safely serviced only if the AC power plug is inserted so that the chassis is connected to the ground side of the AC source.

To confirm that the AC power plug is inserted correctly, do the following: Using an AC voltmeter, measure the voltage between the chassis and a known earth ground. If the reading is greater than 1.0V, remove the AC power plug, reverse its polarity and reinsert. Re-measure the voltage between the chassis and ground.

11. Some TV chassis are designed to operate with 85 volts AC between chassis and ground, regardless of the AC plug polarity. These units can be safely serviced only if an isolation transformer inserted between the receiver and the power source.

12. Some TV chassis have a secondary ground system in addition to the main chassis ground. This secondary ground system is not isolated from the AC power line. The two ground systems are electrically separated by insulating material that must not be defeated or altered.

13. Components, parts and wiring that appear to have overheated or that are otherwise damaged should be replaced with parts that meet the original specifications. Always determine the cause of damage or overheating, and correct any potential hazards.

14. Observe the original lead dress, especially near the following areas: Antenna wiring, sharp edges, and especially the AC and high

voltage power supplies. Always inspect for pinched, out-of-place, or frayed wiring. Do not change the spacing between components and the printed circuit board. Check the AC power cord for damage. Make sure that leads and components do not touch thermally hot parts.

15. Product Safety Notice: Some electrical and mechanical parts have special safety-related characteristics which might not be obvious from visual inspection. These safety features and the protection they give might be lost if the replacement component differs from the original—even if the replacement is rated for higher voltage, wattage, etc.

Components that are critical for safety are indicated in the circuit diagram by shading, ( ) or ( ).

Use replacement components that have the same ratings, especially for flame resistance and dielectric strength specifications. A replacement part that does not have the same safety characteristics as the original might create shock, fire or other hazards.

Precautions

1-2 Samsung Electronics

1-3 Servicing Precautions

1. Servicing precautions are printed on the cabinet. Follow them.

2. Always unplug the unit’s AC power cord from the AC power source before attempting to: (a) Remove or reinstall any component or assembly, (b) Disconnect an electrical plug or connector, (c) Connect a test component in parallel with an electrolytic capacitor.

3. Some components are raised above the printed circuit board for safety. An insulation tube or tape is sometimes used. The internal wiring is sometimes clamped to prevent contact with thermally hot components. Reinstall all such elements to their original position.

4. After servicing, always check that the screws, components and wiring have been correctly reinstalled. Make sure that the portion around the serviced part has not been damaged.

5. Check the insulation between the blades of the AC plug and accessible conductive parts (examples: metal panels, input terminals and earphone jacks).

6. Never defeat any of the B+ voltage interlocks. Do not apply AC power to the unit (or any of its assemblies) unless all solid-state heat sinks are correctly installed.

7. Always connect a test instrument’s ground lead to the instrument chassis ground before connecting the positive lead; always remove the instrument’s ground lead last.

8. Plasma display panels have partial afterimages when a same picture continues to be displayed for a certain time. This happens due to the degradation of brightness caused by a scale-down effect. To prevent such afterimages when displaying a same picture for a certain time, be sure to reduce the level of brightness and contrast. ex) Contrast : 50 or 75, Brightness : 25

9. Plasma display is an array of pixels(cells). Therefore, if at least 99.9% pixels keep normal, the appropriate panel is judged as ‘approved product.’ Even though some of pixels keep luminescent or always light off, do not worry because the panel is approved.

Precautions

Samsung Electronics 1-3

Warning 1 : First read the “Safety Precautions” section of this manual. If some unforeseen circumstance creates a

conflict between the servicing and safety precautions, always follow the safety precautions.

Warning 2 : An electrolytic capacitor installed with the wrong polarity might explode.

1-4 Precautions for Electrostatically Sensitive Devices (ESDs)

1. Some semiconductor (“solid state”) devices are easily damaged by static electricity. Such components are called Electrostatically Sensitive Devices (ESDs); examples include integrated circuits and some field-effect transistors. The following techniques will reduce the occurrence of component damage caused by static electricity.

2. Immediately before handling any semicon ductor components or assemblies, drain the electrostatic charge from your body by touching a known earth ground. Alternatively, wear a discharging wrist-strap device. (Be sure to remove it prior to applying power— this is an electric shock precaution.)

3. After removing an ESD-equipped assembly, place it on a conductive surface such as aluminum foil to prevent accumulation of electrostatic charge.

4. Do not use freon-propelled chemicals. These can generate electrical charges that damage ESDs.

5. Use only a grounded-tip soldering iron when soldering or unsoldering ESDs.

6. Use only an anti-static solder removal device. Many solder removal devices are not rated as “anti-static”; these can accumulate sufficient electrical charge to damage ESDs.

7. Do not remove a replacement ESD from its protective package until you are ready to install it. Most replacement ESDs are packaged with leads that are electrically shorted together by conductive foam, aluminum foil or other conductive materials.

8. Immediately before removing the protective material from the leads of a replacement ESD, touch the protective material to the chassis or circuit assembly into which the device will be installed.

9. Minimize body motions when handling unpackaged replacement ESDs. Motions such as brushing clothes together, or lifting a foot from a carpeted floor can generate enough static electricity to damage an ESD.

Precautions

1-4 Samsung Electronics

CAUTION

These servicing instructions are for use by qualified service personnel only. To reduce the risk of electric shock do not perform any servicing other than that contained in the operating instructions unless you are qualified to do so.

Reference Information

Samsung Electronics 2-1

2. Reference Information

2-1 Tables of Abbreviations and Acronyms

A Ah Å dB dBm

°C °F °K F G GHz g H Hz h ips kWh kg kHz kΩ km km/h kV kVA kW I MHz

Ampere Ampere-hour Angstrom Decibel Decibel Referenced to One Milliwatt Degree Celsius Degree Fahrenheit degree Kelvin Farad Gauss Gigahertz Gram Henry Hertz Hour Inches Per Second Kilowatt-hour Kilogram Kilohertz Kilohm Kilometer Kilometer Per Hour Kilovolt Kilovolt-ampere Kilowatt Liter Megahertz

MV MW MΩ m µA µF µH µm µs µW mA mg mH mI mm ms mV nF

Ω

pF Ib rpm rps s V VA W Wh

Megavolt Megawatt Megohm Meter Microampere Microfarad Microhenry Micrometer Microsecond Microwatt Milliampere Milligram Millihenry Milliliter Millimeter Millisecond Millivolt Nanofarad Ohm Picofarad Pound Revolutions Per Minute Revolutions Per Second Second (Time) Volt Volt-ampere Watt Watt-hour

Table 2-1 Abbreviations

Reference Information

2-2 Samsung Electronics

Table 2-2 Table of Acronyms

ABL AC ACC AF AFC AFT AGC AM ANSI APC APC A/V AVC BAL BPF B-Y CATV CB CCD CCTV Ch CRT CW DC DVM EIA ESD ESD FBP FBT FF FM FS GND G-Y H HF HI-FI IC IC IF

Automatic Brightness Limiter Alternating Current Automatic Chroma Control Audio Frequency Automatic Frequency Control Automatic Fine Tuning Automatic Gain Control Amplitude Modulation American National Standards Institute Automatic Phase Control Automatic Picture Control Audio-Video Automatic Volume Control Balance Bandpass Filter Blue-Y Community Antenna Television (Cable TV) Citizens Band Charge Coupled Device Closed Circuit Television Channel Cathode Ray Tube Continuous Wave Direct Current Digital Volt Meter Electronics Industries Association Electrostatic Discharge Electrostatically Sensitive Device Feedback Pulse Flyback Transformer Flip-Flop Frequency Modulation Fail Safe Ground Green-Y High High-Frequency High Fidelity Inductance-Capacitance Integrated Circuit Intermediate Frequency

I/O L L LED LF MOSFET MTS NAB NEC NTSC OSD PCB PLL PWM QIF R RC RF R-Y SAP SAW SIF SMPS S/N SW TP TTL TV UHF UL UV VCD VCO VCXO VHF VIF VR VTR VTVM TR

Input/output Left Low Light Emitting Diode Low Frequency Metal-Oxide-Semiconductor-Field-Effect-Tr Multi-channel Television Sound National Association of Broadcasters National Electric Code National Television Systems Committee On Screen Display Printed Circuit Board Phase-Locked Loop Pulse Width Modulation Quadrature Intermediate Frequency Right Resistor & Capacitor Radio Frequency Red-Y Second Audio Program Surface Acoustic Wave(Filter) Sound Intermediate Frequency Switching Mode Power Supply Signal/Noise Switch Test Point Transistor Transistor Logic Television Ultra High Frequency Underwriters Laboratories Ultraviolet Variable-Capacitance Diode Voltage Controlled Oscillator Voltage Controlled Crystal Oscillator Very High Frequency Video Intermediate Frequency Variable Resistor Video Tape Recorder Vacuum Tube Voltmeter Transistor

Specifications

Samsung Electronics 3-1

3. Specifications

MODEL

3-1 Display(PDP Monitor)

Display

Remote Control

Display

Remote Control

Voltage

Power Consumption

Number of Pixels

Screen Size

AUDIO Input

AUDIO Output

VIDEO Input

Dimensions

(mm/inch)

Weight

PPM42S2

1038.8(W) x 89(D) x 635(H)mm / 40.9(W) x 3.5(D) x 25(H) Inches

54(W) x 31.5(D) x 220(H)mm / 2.13(W) x 1.24(D) x 8.66(H) Inches

32Kg / 70.55\bs

150g (Including batteries) / 0.33\bs

AC 100-240V, 50/60Hz

310 Watts

852(H) X 480(V)

106Cm / 42 Inches

VIDEO / S-VIDEO

COMPONENT

PC (RGB)

7W + 7W (8Ω)

VIDEO

S-VIDEO

COMPONENT 1(480i) / 2 (480p/720p/1080i)

PC (RGB 1 : D-SUB / RGB 2 : BNC)

3-2 Samsung Electronics

MENO

Alignment and Adjustments

Samsung Electronics 4-1

4. Alignment and Adjustments

4-1 Service Mode

4-1-1 SERVICE MODE ENTRY METHOD (General Transmitter)

1. Turn off the power to make the SET STAND-BY mode.

2. In order to enter the Service Mode, select MUTE-1-8-2-POWER.

* In case entry into SERVICE MODE is unsuccessful, repeat the procedures above.

4-1-2 Initial DISPLAY State in times of SERVICE MODE Switch overs

4-1-2(A) OSD DISPLAY

4-1-2(B) BUTTONS OPERATIONS WITHIN SERVICE MODE

1. PWS364 9. Pinp Control

2. VPC3230 10.OSD Position

3. SDA9400 11. Test Pattern

4. SDA9280 12. Option Table

5. AD9884 - V ideo 13.Reset

6. AD9884 - DTV/PC

7. CXA2101Q-1

8. CXA2101Q-2

Release Time :

Menu Joystick UP/DOWN Joystick (LEFT/RIGHT)

Entire menu display Cursor move to select items Enable to increase and decrease the data of the selected items

Alignment and Adjustments

4-2 Samsung Electronics

4-1-3 Details of Control

4-1-3(A) PW364

No OSD

H Position

V Position

Red Gain

Green Gain

Blue Gain

Red Offset

Green Offset

Blue Offset

APL On/Off

High Light

Low Light

Shit Pixel

Test

Pixel Number

Shift Line

Time

113

139

113

139

Default of MODE

VIDEO / S-VHS Component1 Component2 PC

148

133

148

133

125

129

125

129

Alignment and Adjustments

Samsung Electronics 4-3

4-1-3(B) VPC3230

Bright YUV

Cont YUV

IF Comp(IFC)

Chroma band(CBW)

Ena Luma

HPLL Speed

Luma Delay

3230 Bright

3230 Contrast

H LPF Y/C(LPF2)

H LPF Chroma(CBW2)

H Peaking (Filter)

Coaring Off/On

Default of MODE

195

146

195

146

VIDEO / S-VHS Component1 Component2 PC

DO NOT ENTER

No OSD

4-1-3(C) SDA9400

SNR On

VCSNR On

HCSNR On

DTNR On

TNRCLY

TNRCNC

Default of MODE

VIDEO / S-VHS Component1 Component2 PC

DO NOT ENTER

No OSD

Alignment and Adjustments

4-4 Samsung Electronics

CTI Thresh

CTI Trawid

Y-Delay

LPF Gain

BPF Gain

HPF Gain

Phacom

Cor

Default of MODE

VIDEO / S-VHS Component1 Component2 PC

DO NOT ENTER

4-1-3(E) AD9884

Red Gain

Green Gain(Fix)

Blue Gain

Red Offset

Green Offset(Fix)

Blue Offset

Current

Default of MODE

142

132

143

132

143

VIDEO / S-VHS Component1 Component2 PC

4-1-3(D) SDA9280

No OSD

145

132

137

Alignment and Adjustments

Samsung Electronics 4-5

4-1-3(F) CXA2101Q-1

Default of MODE

VIDEO / S-VHS Component1 Component2 PC

No OSD

Sub Bright

Limit Level

System

D-Color

R Drive

G Drive

B Drive

R Cutoff

G Cutoff

B Cutoff

ABL Mode

ABL TH

H sep sel

Fix Sync

V Time Con

H Width

HHD Time Con

Picture

DO NOT ENTER

Alignment and Adjustments

4-6 Samsung Electronics

4-1-3(G) CXA2101Q-2

Default of MODE

VIDEO / S-VHS Component1 Component2 PC

No OSD

HS Mask

Sub Cont

Sub Color

Sub Hue

Sub SHP

R-Y/R

R-Y/B

G-Y/R

G-Y/B

PABL Level

SHP FO

Pre/Over

CTI Level

LTI Level

DC-Tran

D-Pic

Color

Brightness

DO NOT ENTER

Alignment and Adjustments

Samsung Electronics 4-7

4-1-3(H) PinP Control

Pip HPos

Pip VPos

Bright YUV

Cont YUV

Luma Delay

3230 Bright

3230 Contrast

Default of MODE

195

VIDEO / S-VHS Component1 Component2 PC

No OSD

Alignment and Adjustments

4-8 Samsung Electronics

Alignment and Adjustments

4-1-4 White Balance Adjust Method

1. Press MUTE-1-8-2-POWER to enter the factory mode.

2. Enter "5. AD9884 - Video" or " 6. AD9884 - DTV/PC".

3. Adjust LOW coordinates as R,B OFFSET and HIGH coordinates as R,B GAIN. (GREEN is fixed)

4. Press "Menu" Key in remote control to exit.

5. Enter "1. PW364A".

6. Adjust LOW light as "Low Light".

7. Adjust HIGH light as "High Light".

- W/B Adjustment SPEC(Suwon Factory Toshiba PATTERN)

‹ Condition of Signals

! Video,S-VHS, Component1(DVD) : 10-Gray: (0,1,

@,3,4,5,^,7,8,9,10)-ShibaSoku TG71BX @ Component 2(DTV) : 9 Gray : (0,1,@,3,4,5,^,7,8,9) - LT446 1080i output

# PC : 16 Gray (0,1,2,#,4,5,6,7,8,(,10....15) - TP36B

W/B x y Y(fL) T(K)

VIDEO

(10 Gray)

D T V

(9 Gray)

P C

(16 Gray)

High (^)

Low (@)

High (^)

Low (@)

High (()

Low (#)

Picture Quality

Assessment

Picture Quality

Assessment

Picture Quality

Assessment

285

295

0.7

0.95

0.65

9200

Alignment and Adjustments

Samsung Electronics 4-9

Alignment and Adjustments

4-2 PPM42S2 PC Input Mode

IBM PC/AT

Compatible

640 X 350

640 X 400

720 X 400

640 X 480

848 X 480

852 X 480

800 X 600

1024 X 768

N/P

Video Signal Dot Line

70.086

85.080

70.087

85.039

59.940

72.809

75.000

85.008

60.000

56.250

60.317

72.188

75.000

85.061

60.004

70.069

75.029

84.997

31.469

37.861

31.469

37.927

31.469

37.861

37.500

43.269

29.800

31.731

35.156

37.879

48.077

46.875

53.674

48.363

56.476

60.023

68.677

N/P

Vertical

Frequency (Hz)

Horizontal

Frequency (KHz)

Vertical

Polarity

Horizontal

Polarity

Alignment and Adjustments

4-10 Samsung Electronics

Alignment and Adjustments

4-3 Discharge Voltage Adjustments When Replacing Main Assay

PDP Driving related Board Layou

Voltage Adjustments

n Adjust all of variable resistances except V9, VG clockwise to decrease the voltage.

For PPM42S2 models, readjust VR (6V) to 5.9V (±0.2V).

n When replacing the X, Y driving boards, avoid waveform adjustments using variable resistance as they

have been adjusted according to the characteristics of PDP panel.

Samsung Electronics 4-11

Alignment and Adjustments

4-4 Fault Finding Using MULTI METER

Parts defects can be found for DIODE TRANSISTOR IC, using MULTI TEST including Forward/Reverse direction Multi Test. Of course, in case resistance of several ohms and COIL are connected in parallel circuit, the lock out circuit parallel connected to part must be severed.

1.DIODE

2. TRANSISTOR

l For NPN(KSC815-Y, 2SC2068, 2SC2331-Y)

l For PNP(KSA539-Y)

Forward Direction

Hundreds of ohms

Reverse Direction

Infinity

Between Anode and Cathode

C (COLLECTOR)

B(BASE)

C (COLLECTOR)

B(BASE)

E (EMITTER)

Forward Direction Hundreds of ohms Hundreds of ohms

Infinity

Reverse Direction

Infinity Infinity Infinity

Between B and E Between B and C Between E and C

Forward Direction Hundreds of ohms Hundreds of ohms

Infinity

Reverse Direction

Infinity Infinity Infinity

Between B and E Between B and C Between E and C

+- +-

4-12 Samsung Electronics

Alignment and Adjustments

3. IC (INTEGRATED CIRCUIT)

IC has built in DIODE against overvoltage in PIN. Generally, except for internal circuit defects, IC defects can be found, by measuring the DIODE.

› Defects have SHORT(0 ohm) for both forward and reverse direction.

Hundreds of ohms

Forward Direction

Reverse Direction

Varying depending on IC but generally normal

Infinity in DIODE TEST MODE

Circuit Operation Description

Samsung Electronics 5-1

5. Circuit Description

5-1 Power supply

5-1-1 Outline(PDP SMPS)

Considering various related conditions, the switching regulator with good efficiency and allowing for its small size and lightweight was used as the power supply for PDP. Most of the power supply components used forward converter, and Vsamp and Vsb used simple flyback converter. To comply with the international harmonics standards and improve the power factor, active PFC (Power Factor Correction) was used to rectify AC input into +400V DC output, which in turns used as input to the switching regulator.

5-1-2 42"SD SMPS SPECIFICATION

5-1-2(A) INPUT

PDP-42PS board is designed so that input power can be used within AC 90 VAC to 264 VAC with 50/60Hz ± 3Hz.

5-1-2(B) OUTPUT

PDP-42PS board provides 13 output switching power supplies (+165Vs, +220Set, +185Ve, +75Va, +80Scan, +18Vg, +5Vsb, +5V(D), +5.9V(A), +12V. +9V, +12Vfan, and +12Vsamp). The output voltage, and current requirements for continuous operation are stated below (Table 3).

Table1. Specifications of Output Power Supplies for PDP SMPS

Output Name

Vscan

Vset

Vfan

V5(A)

V5(D)

Vsb

V12

Vsamp

Output Voltage

+165V

+75V

+80V

+220V

+185V

+18.3V

+12V

+9V

+5.9V

+5.3V

+5V

+12V

Output Current

1.4A

0.5A

0.05A

0.3A

0.8A

0.3A

1.0A

3.5A

0.4

1.2A

1.5A

Using in PDP driving

Sustain Voltage of Drive Board

Address Voltage of Drive Board

Analog IC Drive Voltage of Video Board

IC Drive Voltage of Logic Board

Stand-by for Remote Control

Circuit Operation Description

5-2 Samsung Electronics

Table 2. Specifications to Protect PDP SMPS

Division

+5V

OCP Current

10A

OVP Voltage

195V

90V

6.2V

Short Circuit

O.K

5-1-2(C) FUNCTION OF BOARD

(1) Remote control

Using 250V/ 10A relay, the board makes remote control available.

(2) Free voltage

The board designed so that input voltage can be used within 90 VAC to 264VAC.

(3) Embedded thermal sensor

The board is equipped with thermal sensor to detect the internal temperature of the unit, and to short relay when the internal temperature is higher than specified temperature so as to shutdown the unit.

(4) Improvement of power factor

The board is designed using PFC circuit so that PF (Power Factor) can be over 0.95, because low PF can be a problem in high voltage power.

(5) Protection

The OCP (Over Current Protection), the OVP (Over voltage Protection), and the Short Circuit Protection functions are added against system malfunction.

Circuit Operation Description

Samsung Electronics 5-3

5-1-2(D) PDP-PS-42 BLOCK DIAGRAM

Circuit Operation Description

5-4 Samsung Electronics

(1) AC-DC Converter

PDP-42PS outputs +400V DC from the common AC power supply using the active PFC booster converter. This converter is designed for improving the power factor and preventing the noise with high frequency and finally becomes the input power system for the switching regulator on the output side.

(2) Auxiliary Power Supply

The auxiliary power supply is a block generating power of •Ï-com for remote controlling. Once the power plug is inserted, this block always comes into operation, causing •Ï-com to get into the standby state for the output. Thus, this output is called the stand-by voltage. And with the relay ON signal inputted through the remote controller, this block turns the mechanical switch of relay to ON for driving the main power supply.

(3) Implementation of Sustain Voltage

As the main part of a SMPS for PDP, sustain voltage must supply a high power, +165V/ 1.4A. It is designed using forward converter basically. At the output stage two 90V converters are connected serially for high efficiency and reduction of system size against a single 180V converter.

(4) Implementation of Small Power Output (Va, V(D), V(A), Vfan, V9, Vsamp, Ve, Vset, Vscan, V12, and

Vg)Vset, Ve, and Vscan used DC-DC module. V(D), Va, V12, and Vfan used forward converter, and Vsamp used flyback converter. V(A), V9, and Vg are simply implemented using switching regulator.

5-1-3 Requirements of PDP SMPS

Since SMPS does not operate alone, but it operates with the load of the whole system, it should be designed carefully considering the load of the system. In addition, it should be designed considering emerging issues such as EMC, and protection against heat as well as system stability especially.

5-1-3(A) SAFETY AND REMOTE CONTROL CAPABILITY

Stability is one of the most important requirements for SMPS. SMPS should be designed to prevent abnormal status due to abnormal load variation so as to keep the system stable, and guarantee customer safety. The protection circuits of SMPS include over-current protection (OCP), over voltage protection (OVP), and under voltage lock-out (UVLO), and short circuit protection circuit. Although each circuit can be implemented by various procedures, the most popular is implementing with comparator that compares current value with that of standard and determine abnormality of the circuit. In addition, surge current protection, insulation management, and static electricity protection circuit should be added, because it uses commercial power source as an input. PDP SMPS should be designed using auxiliary power and relay to provide remote control capability.

Circuit Operation Description

Samsung Electronics 5-5

5-1-3(B) THE RELATION BETWEEN POWER CONSUMPTION AND POWER CONVERSION Efficiency

The power consumption and the power conversion efficiency of SMPS affect protection against heat and system operation much. [ If the power conversion efficiency of 100W SMPS is 70%, is the power loss of internal circuit 30W? ] Output power consumption Po is determined by the multiplication of DC output voltage Vo and output current Io. Input power consumption Pi is determined by the addition of output power consumption Po and internal power loss of SMPS Pl. Provided that the power conversion efficiency is _,

If the power conversion efficiency of 100W SMPS is 70%, the internal power loss is about 42.8W by Equation (1). If the power conversion efficiency of 400W SMPS for 42"SD is 82%, the internal power loss is 87.8W by Equation (1). Table 4 shows internal power loss as a function of output power for various power conversion efficiencies.

Table 4. Power Conversion Efficiency vs. Internal Power Loss

100

120

140

160

180

200

120 140 160 180 200 240220 260 280 300

50%

60%

90%

70%

80%

Internal

Power

Loss ( W)

Direct Current Output Power (W)

Circuit Operation Description

5-6 Samsung Electronics

5-1-3(C) PFC (Power Factor Correction) Circuit Descriptions

The current electric devices use DC power supply and require a rectifier circuit converting AC into DC. As most rectifier circuits apply a capacitor input type, the rectifier circuit becomes the core of the occurrence of harmonics with lower reverse rate.If various electronic and electric devices are connected to a power system, high-frequency current will occur due to a power rectifier circuit, a phase control circuit with power input current of non-sine wave, or components with non-linear load characteristics, such as capacitor, inductor, etc. As the result, the disturbance of voltage occurs, and finally a power capacitor or a transformer generates heat, fire or noise occurs, controls malfunction, or the accessed devices abnormally operate or their lives are shortened.To prevent those symptoms, IEC (International Electrotechnical Commission) regulated standards for Power Supply Harmonics. (Refer to IEC 1000-3-2.)Figure 8 shows the basic structure of Active Boost PFC and waveforms.

Standards for Power Supply Harmonics

Scale: Devices accessed to 220V/380V, 230V/400V, 240V/425V and lower than 16A (IEC 100-3-2) Devices with AC 230V and lower than 16A (IEC 555-2)

Applied Classes :

♦ Class A : Devices not included in another class ♦ Class B : Portable tools ♦ Class C : Lighting devices ♦ Class D : Devices with special current waveforms

Application Schedule : Except the devices less than rating input of 75W (1996~1999)

Except the devices less than rating input of 50W (2000 and after)

Circuit Operation Description

Samsung Electronics 5-7

5-1-3(D) CONCLUSION

Although SMPS (Switching Mode Power Supply) enables small lightweight high-power consumption power design, it is hard to be used when stability and precise control are required. Power stage for PDP can be designed using the lightweight SMPS feature. It is important to design SMPS considering system load, stability, and related international standards.

The architecture and the pulse of active boost PFC

Circuit Operation Description

5-8 Samsung Electronics

5-2 Driver Circuit

5-2-1 Driver Circuit Overview

5-2-1(A) WHAT IS THE DEFINITION OF DRIVE CIRCUIT?

It is a circuit generating an appropriate pulse (High voltage pulse) and then driving the panel to implement images in the external terminals (X electrode group, Y electrode group and address electrode), and this high voltage switching pulse is generated by a combination of MOSFET’s.

5-2-1(B) PANEL DRIVING PRINCIPLES

In PDP, images are implemented by impressing voltage on the X electrode, Y electrode and address electrode, components of each pixel on the panel, under appropriate conditions. Currently, ADS (Address & Display Separate: Driving is made by separating address and sustaining sections) is most widely used to generate the drive pulse. Discharges conducted within PDP pixels using this method can largely be classified into 3 types, as follows:

(1) Address discharge : This functions to generate wall voltage within pixels to be lighted by addressing

information to them (i.e., impressing data voltage)

(2) Sustain discharge : This means a display section where only pixels with wall voltage by the address

discharge display self-sustaining discharge by the support of such wall voltage. (Optic outputs realizing images are generated.)

(3) Erase discharge : To have address discharge occur selectively in pixels, all pixels in the panel must

have the same conditions (i.e., the same state of wall and space electric discharges). The ramp reset discharge section, therefore, is important to secure the drive margin, and methods most widely used to date include wall voltage controlling by ramp pulse.

+ 113 hidden pages