SAMSUNG DVD858V Service Manual

DIGITAL VIDEO DISC PLAYER

DVD858V
DVD878KV

DVD-858V

DVD-878KV

Manual

DIGITAL VIDEO DISC PLAYER CONTENTS

1. Precautions

2. Reference Information

3. Product Specifications and

4. Disassembly and Reassembly

5. Troubleshooting

6. Exploded View and Parts List

7. Electrical Parts List

8. Block Diagram

9. PCB Diagrams

10. Wiring Diagram

11. Schematic Diagrams

Samsung Electronics 1-1

1. 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 pretective devices, including :
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 the picture tube and the cabinet mask,
excessively wide cabinet ventilation slots, and
improperly fitted back covers.

If the measured resistance is less than 1.0 megohm
or greater than 5.2 megohms, an abnormality exists
that must be corrected before the unit is returned
to the customer.

4. Leakage Current Hot Check (See Fig. 1) :
Warning : Do not use an isolation transformer
during this test. Use a leakage current tester or a
metering system that complies with American
National Standards Institute (ANSI C101.1,
Leakage Current for Appliances), and Underwriters
Laboratories (UL Publication UL1410, 59.7).

5. With the unit completely reassembled, plug the AC
line cord directly the power outlet. With the unitÕs
AC switch first in the ON position and then OFF,
measure the current between a known erath
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

0.5 milliamp. Reverse the power-plug prongs in the
AC outlet and repeat the test.

6. X-ray Limits :
The picture tube is designed to prohibit X-ray
emissions. To ensure continued X-ray protection,
replace the picture tube only with one that is the
same type as the original.

Fig. 1 AC Leakage Test

7. Antenna Cold Check :
With the unitÕs 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.

8. High Voltage Limit :
High voltage must be measured each time
servicing is done on the B+, horizontal deflection
or high voltage circuits.

Heed the high voltage limits. These include the

X-ray protection Specifications Label, and the
Product Safety and X-ray Warning Note on the

service data schematic.

9. Some semiconductor (Òsolid stateÓ) 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.

10. Immediately before handling sny semiconductor

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.)

Device
Under

Test

(Reading should
not be above

0.5mA)
Leakage

Currant
Tester

Earth
Ground

Test all

exposed metal

surfaces

Also test with
plug reversed
(using AC adapter
plug as required)

2-Wire Cord

Precautions

1-2 Samsung Electronics

11. 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.

12. 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
manufacturerÕs warranty.

13. 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.

14. 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.

15. 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.

16. Always connect a test instrumentÕs ground lead to
the instrument chassis ground before connecting
the positive lead; always remove the instrumentÕs
ground lead last.

17. 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, out­of-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.

18. Picture Tube Implosion Warning :
The picture tube in this receiver employs
Òintegral implosionÓ protection. To ensure
continued implosion protection, make sure that
the replacement picture tube is the same as the
original.

19. Do not remove, install or handle the picture tube
without first putting on shatterproof goggles
equipped with side shields. Never handle the
picture tube by its neck. Some Òin-lineÓ picture
tubes are equipped with a permanently attached
deflection yoke; do not try to remove such
Òpermanently attachedÓ yokes from the picture
tube.

20. 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.

21. Cautions for handling Pick-up
Body grounding (hand) : Be sure to wear a wrist
strip with one side grounded. (Impedance :

Below 10-8½ )
Work table grounding : Put A grounded electric
conductor such as copper plate on tne work
table.

Caution: Do not let clothing touch the product
(to prevent possible damage from static electric­ty).

FPC operation : Handle the FPC carefully because
it is easily damaged.

Precautions

Samsung Electronics 1-3

1-2-1 Disassembly

1) Remove the power cable.

2) Switch LD SW3 on deck PCB to ÔSÕ before remo
ing the FPC ( inserted into Main PCB CN1.
See Fig 1-2)

3) Disassemble the deck.

4) Disassemble the deck PCB.

5) Replace the Pick-up.

Fig. 1-2

1-2-2 Assembly

1) Replace the Pick-up.

2) Assemble the deck PCB.

3) Reassemble the deck.

4) Switch LD SW3 on deck PCB to ÔOÕ and insert FPC
into Main PCB CN1 (See Fig 1-2).

1-2 Pick-up disassembly and ressembly

Note : If the assembly and disassembly are not done in correct sequence, the Pick-up may be damaged.

O

S

LD

SW3

FPC

Precautions

1-4 Samsung Electronics

MEMO

Samsung Electronics 3-1

3. Product Specifications

The specifications and design may be changed without notice. The weight and dimensions are approximate.

MODEL DVD858V DVD878KV

G

E

N

E
R
A

L

D

I
S
C

V O

I U
D T

E P

O U

T

A O
U U

D T

I P

O U

T

Free Voltage, 50/60Hz
23W

4.4Kg

(W)420mm x (D)339mm x (H)120mm
+ 5 °C ~ 35 °C
50% ~ 95%
Reading Speed ; 1.2 ~ 1.4mm/sec
Maximum Play Time ; 135 minutes
Reading Speed ; 1.2 ~ 1.4mm/sec
Maximum Play Time ; 74 minutes
Reading Speed ; 1.2 ~ 1.4mm/sec
Maximum Play Time ; 74 minutes
Reading Speed ; 1.2 ~ 1.4m/sec
Maximum Play Time ; 74 minutes(Video + Audio)

2 channel ; 1.0Vp-p
R(Red) ; 0.714Vp-p
G(Green) ; 0.714Vp-p
B(Blue) ; 0.714Vp-p
S(Sync) ; 4.0Vp-p
Luminance Signal ;1Vp-p (75Ω load)
Color Signal ; 0.286Vp-p (75Ω load)

L(1/L), R(2/R)
F/L, F/R, R/L, R/R, C/T, S/W
Analog ; 2Vrms(1KHz)
Digital ; 5Vp-p

* Frequency Response ; 4Hz ~20KHz, S/M Ratio : 105dB
* Dynamic Range ; 95dB
* Total Harmonic Distortion 0,005%

Power Requirements
Power Consumption
Weight
Set Size
Operating Temperature Range
Operating Humidity Range

DVD

(DIGITAL VERSATILE DISC

CD : 12cm

(COMPACT DISC)

CD : 8cm

(COMPACT DISC)

VIDEO - CD

12cm

RCA JACK

SUPER VIDEO

2 channel
5 channel

Output Level

Digital Frequency

Response

Free Voltage, 50/60Hz
23W

6.6Kg

(W)420mm x (D)339mm x (H)120mm
+ 5 °C ~ 35 °C
50% ~ 95%
Reading Speed ; 1.2 ~ 1.4mm/sec
Maximum Play Time ; 135 minutes
Reading Speed ; 1.2 ~ 1.4mm/sec
Maximum Play Time ; 74 minutes
Reading Speed ; 1.2 ~ 1.4mm/sec
Maximum Play Time ; 74 minutes
Reading Speed ; 1.2 ~ 1.4m/sec
Maximum Play Time ; 74 minutes(Video + Audio)

2 channel ; 1.0Vp-p
R(Red) ; 0.714Vp-p
G(Green) ; 0.714Vp-p
B(Blue) ; 0.714Vp-p
S(Sync) ; 4.0Vp-p
Luminance Signal ;1Vp-p (75Ω load)
Color Signal ; 0.286Vp-p (75Ω load)

L(1/L), R(2/R)
F/L, F/R, R/L, R/R, C/T, S/W
Analog ; 2Vrms(1KHz)
Digital ; 5Vp-p

* Frequency Response ; 4Hz ~20KHz, S/M Ratio : 95dB
* Dynamic Range ; 90dB
* Total Harmonic Distortion 0,02%

Product Specifications

3-2 Samsung Electronics

MEMO

Samsung Electronics 4-1

4. Disassembly and Reassembly

4-1 DVD878KV Exterior and PCB Disassembly

4-1-1 Door-tray

1. Supply power and open Tray Œ.

2. Disassemble the door-tray ´ in direction of arrow.

3. Close Tray Πand power off.

Note : If Tray Œ doesnÕt open, insert a clip ˇ into the hole (as shown in detailed drawing), and open Tray Œ

manually.

Fig. 4-1

70mm

TRAY

1

DOOR-TRAY

2

CLIP

3

Disassembly and Reassembly

4-2 Samsung Electronics

4-1-2 Top cabinet

1. Remove 3 screws Πon the back panel.

2. Remove 4 screws ´, ˇ on the left and right side.

3. Lift up the top cabinet in direction of arrow.

Fig. 4-2

CABINET-TOP

2 SCREWS

2 SCREWS

SCREWS

11

2

3

Disassembly and Reassembly

Samsung Electronics 4-3

4-1-3 Panel-Front, PCB-Front

1. Remove 4 knob-volumes Œ.

2. Remove 2 screws ´, ˇ on the left and right side of panel-front.

3. Remove 2 screws ¨ on the top of panel-front.

4. Remove 8 screws ˆ to fix PCB-front and disassemble PCB-front.

Fig. 4-3

KNOB-VOLUME

PANEL-FRONT

SCREW

8 SCREWS

SCREW

2 SCREWS

HOLDER-PLAY

PCB-FRONT

HOLDER­KEY CON

2

5

4

1

3

Disassembly and Reassembly

4-4 Samsung Electronics

4-1-4 PCB-MAIN, PCB-KARAOKE, PCB-SMPS

1. Remove 4 screws to fix PCB-MAIN and disconnect the connector connected DECK, PCB-SMPS by lifting it up
towards arrow ÒAÓ.

2. Remove 2 Holder-PCB ´ inserted in PCB-MAIN.

3. Remove 4 screws ¨ and then remove cover-Rear ˆ and Ground-Rear Ø.

4. Remove 1 screw ˇ and then remove BRKT-PCB assÕy.

5. Remove 5 screws ∏ and 1 spacer-PCB ” and then lift PCB-SMPS up.

6. Remove 2 screws ’ and then remove PCB-KARAOKE in the direction of arrow ÒBÓ.

Fig. 4-4

PCB-MAIN

PCB-SMPS

BRKT-PCB ASS'Y

"B"

"A"

ASS'Y-BOTTOM

PCB-KARAOKE

4 SCREWS

1

SCREW

3

HOLDER­PWB

2

4 SCREWS

4

COVER-REAR

5

5 SCREWS

7

GROUND-REAR

6

2 SCREWS

9

SPACER-PCB 1EA

8

Disassembly and Reassembly

Samsung Electronics 4-5

4-1-5 Deck, Frame-chassis

1. Remove 4 screws Πfrom the deck and lift it up.

2. Remove 4 screws ´ from the frame-chassis and lift it up.

Fig. 4-5

CHASSIS-FRAME

DECK

4 SCREWS

4 SCREWS

2

1

Disassembly and Reassembly

4-6 Samsung Electronics

4-2 DVD858V Exterior and PCB Disassembly

4-2-1 Door-tray

1. Supply power and open Tray Œ.

2. Disassemble the door-tray ´ in direction of arrow.

3. Close Tray Πand power off.

Note : If Tray Œ doesnÕt open, insert a clip ˇ into the hole (as shown in detailed drawing), and open Tray Œ

manually.

Fig. 4-6

70mm

TRAY

DOOR-TRAY

CHIP

22

11

33

Disassembly and Reassembly

Samsung Electronics 4-7

4-2-2 Top cabinet

1. Remove 3 screws Πon the back panel.

2. Remove 4 screws ´, ˇ on the left and right side.

3. Lift up the top cabinet in direction of arrow.

Fig. 4-7

CABINET-TOP

2SCREWS

3SCREWS

2SCREWS

22

33

11

Disassembly and Reassembly

4-8 Samsung Electronics

4-2-3 Front

1. Remove 2 screws Œ, ´ on the left and right side of panel-front assÕy

2. Remove 2 screws ˇ on the bottom of cover-panel assÕy and disassemble the front.

3. Remove 2 screws ¨ from PCB-front.

4. Remove 9 hooks to fix PCB-front and disassemble PCB-front.

5. Remove 2 screws ˆ on the top of cover-panel assÕy

6. Remove 4 top hooks Ø and 5 bottom hooks ∏ and disassemble the cover-panel assÕy.

Fig. 4-8

2 SCREWS

1 SCREW

4 HOOKS

2 SCREWS

COVER-PANEL ASS'Y

5 HOOKS

PANEL-FRONT ASS'Y

1 SCREW

2 SCREWS

PCB-FRONT

22

66

55

44

11

77

33

Disassembly and Reassembly

Samsung Electronics 4-9

4-2-4 PCB-MAIN, PCB-SMPS

1. Remove 4 screws Πto fix PCB-MAIN.

2. Remove 2 Holder-PCB ´ inserted in PCB-MAIN and lift up PCB-MAIN.

3. Remove 3 screws ˇ from PCB-SMPS.

4. Remove 3 Spacer-PCB ¨ inserted in PCB-SMPS and lift up PCB-SMPS.

5. Remove 2 screws ˆ to fix BRKT-PCB assÕy.

Fig. 4-9

4 SCREWS

2 SCREWS

PCB-MAIN

PCB-SMPS

3 SCREWS

BRKT-PCB ASS'Y

HOLDER-PCB

SPACER-PCB

ASS'Y BOTTOM

11

55

22

44

33

Disassembly and Reassembly

4-10 Samsung Electronics

4-2-5 Deck, Frame-chassis

1. Remove 4 screws Πfrom the deck and lift it up.

2. Remove 4 screws ´ from the frame-chassis and lift it up.

Fig. 4-10

4 SCREWS

DECK

FRAME-CHASSIS

4 SCREWS

11

22

Disassembly and Reassembly

Samsung Electronics 4-11

4-3 PCB Locations

Fig. 4-11

PCB-MAIN

PCB-SMPS

PCB-FRONT

PCB-KARAOKE

DVD878KV

DVD858V

PCB-MAIN

PCB-FRONT

PCB-SMPS

Disassembly and Reassembly

4-12 Samsung Electronics

4-4 Connectors

4-4-1 DVD878KV

Fig. 4-12

No. Connector wafer No. Direction Connector wafer No.

ΠFCN1 PCB-FRONT PCB-MAIN VCN11
´ KW2 PCB-KARAOKE PCB-MAIN KCN1
ˇ FCN3 PCB-FRONT PCB-KARAOKE KW1
¨ KW1 PCB-DECK PCB-MAIN FCN3
ˆ CN5 PCB-DECK PCB-MAIN CN1
Ø CN1 PCB-MAIN PCB-DECK CN5
∏ VCN11 PCB-MAIN PCB-FRONT FCN1
” PCN1 PCB-MAIN PCB-SMPS PCN2
’ KCN1 PCB-MAIN PCB-KARAOKE KW2
˝ PCN2 PCB-SMPS PCB-MAIN PCN1

9

8

6

7

2

6

5

1

2

4

5

PCB-MAIN

10

PCB-SMPS

4

PCB-KARAOKE

3

PCB-FRONT

Disassembly and Reassembly

Samsung Electronics 4-13

4-4-2 DVD858V

Fig. 4-13

PCB-FRONT

1

PCB-SMPS

4

2

6

PCB-MAIN

3

5

No. Connector wafer No. Direction Connector wafer No.

ΠFCN1 PCB-FRONT PCB-MAIN VCN11
´ VCN11 PCB-FRONT FCN1
ˇ CN5 DECK PCB-MAIN CN1
¨ CN1 DECK CN5
ˆ PCN02 PCB-SMP PCB-MAIN VCN13
Ø VCN13 PCB-SMPS PCN02

Disassembly and Reassembly

4-14 Samsung Electronics

4-5 Deck Disassembly

4-5-1 Tray

1. Remove 2 screws Œ and lift up the assÕy-deck clamper ´.

2. Insert a clip into Emergency hole, and push Gear-Cam Center ˇ. When the tray ¨ comes out a little, pull it in

direction of arrow ÒCÓ.

3. Pull the tray ¨ to disassemble, while simultaneously pushing the hook ˆ, Ø in direction of arrow ÓAÓ, ÒBÓ.

Fig. 4-14

"A"

"C"

" B "

HOOK

EMERGENCY
HOLE

CLIP

33

GEAR-CAM CENTER

TRAY

HOOK

11

2 SCREWS

ASS'Y-DECK CLAMPER

22

55

66

33

44

Disassembly and Reassembly

Samsung Electronics 4-15

4-5-2 Ass’y-Deck DVD

1. Remove 2 screws Œ and disassemble the assÕy-PCB deck ´.

2. Disassemble the assÕy-deck DVD ¨ in direction of arrow ÒBÓ, while simultaneously pushing the hook ˇ in

direction of arrow ÓAÓ.

Fig. 4-15

"B"

"A"

ASS'Y-DECK DVD

33

HOOK

ASS'Y-PCB DECK

2 SCREWS

11

22

33

44

Disassembly and Reassembly

4-16 Samsung Electronics

4-5-3 Chassis-Main parts

1. Lift up the gear-tray Œ, remove 1 screw ´ and lift up the gear-cam center ˇ.

2. Lift up the belt-pulley ¨, remove 1 screwˆ and lift up the pulley-gear Ø.

3. Remove 1 screw ∏ and lift up the gear-tray A ” and gear-cam sub ’.

4. Remove 2 screws ˝ and disassemble the assÕy-motor load Ô.

5. Remove 1 screw  and disassemble the lever-open S/W Ò.

6. Lift up the shaft-syncro Ú and remove the 2 gear-syncro Æ in both directions.

Assembling : Adjust the shaft end of motor-feed so that it is exactly equal to the height of the hump in gear pole

of assÕy-gear magnet.

Fig. 4-16

GEAR-CAM CENTER

1 SCREW

GEAR-CAM SUB

11

GEAR-TRY

GEAR-TRY A

BELT-PULLEY

1 SCREW

PULLEY-GEAR

2 SCREWS

LEVER-OPEN S/W
1 SCREW

MOTOR,PULLEY ASSEMBLING : ADJUST THE END OF MOTOR
SHAFT SAMELY AS HEIGHT OF PULLEY AT ASSEMBLY.

ASS'Y-MOTOR LOAD

GEAR-SYNCHRO

SHAFT-SYNCHRO

GEAR-SYNCHRO

GEAR-CAM SUB

1 SCREW

33

GEAR-CAM-CENTER

POINT

1212

1313

1010

66

55

44

77

88

11

33

22

99

33

99

1515

1414

1515

1111

Disassembly and Reassembly

Samsung Electronics 4-17

4-5-4 Ass’y deck

1. Remove 4 screws Œ.

2. Lift up the assÕy-deck ´.

Fig. 4-17

4 SCREWS

ASS'Y-DECK

11

22

Disassembly and Reassembly

4-18 Samsung Electronics

4-5-5 Ass’y-Deck parts

1. Remove 3 screws Œ and disassemble 3 holder-cams ´.

2. Disassemble the rack-slide ˆ and assÕy-pickup Ø, while simultaneously removing the shaft-P/U-L ¨,
shaft-P/U-R ¨.

3. Remove 3 screws ∏ and disassemble the assÕy-motor spindle ”.

4. Remove the washer-plain ’ and disassemble the assÕy-gear feed AU/AL ˝.

5. Remove the washer-plain Ô and disassemble the gear-feed B .

6. Remove the washer-plain Ò and disassemble the assÕy-gear feed CU/CL Ú.

7. Disassemble the assÕy-gear magnet Æ.

8. Remove 2 screws ı and disassemble the assÕy-PCB hall sensor ˜.

9. Remove 1 screw ¯ and disassemble the motor-feed ˘.

Assembling : Adjsut the shaft end of motor-feed ˘ so that it is exactly equal to the height of the hump in gear

pole of assÕy-gear magnet.

Fig. 4-18

HUMP

MOTOR SHAFT

<DETAILED DRAWING : UPPER SIDE>

HOLDER-CAM

3 SCREWS

ASS'Y-MOTOR
SPINDLE

3 SCREWS

SHAFT-P/U-L

ASS'Y-PICKUP

MOTOR-FEED

1 SCREWS

ASS'Y-PCB HALL SENSOR

2 SCREWS
ASS'Y-GEAR MAGNET
ASS'Y-GEAR FEED AU/AL

WASHER-PLANE

GEAR FEED B

WASHER-PLANE

ASS'Y-GEAR FEED CU/CL

WASHER-PLANE

SHAFT-P/U-R

RACK-SLIDE

1818

1919

1717

1616
1515
1414

9 9
1212
1111
1414
1313

5 5

44

66

33

77

88

11

22

Samsung Electronics 2-1

2. Circuit Operating Description

2-1 SMPS circuit description

2-1-1 Comparison between linear power supply and SMPS

2-1-1(a) LINEAR

Fig. 2-1

3 Waveform/Description

Input : Common power to transformer(Vp)

Fig. 2-2

The output Vs of transformer is determined by the ratio
of 1st Np and 2st Ns.
Vs = (Ns/Np) x Vp

Fig. 2-3

Vout is output (DC) by diode and
condensor.

Fig. 2-4

Vreg

Vout

+
–

+

+

–

Vs

(Ns)

Vp

(Np)

Regulator

Common power
(Ex.220V60Hz)

Vs

t

0

220 2 V

20us

Vs

t

0

Vout

t

0

Reference Information

2-2 Samsung Electronics

3 Advantages and disadvantages of linear power supply

a. Advantages :

Little noise because the output waveform of transformer is
sine wave.

b. Disadvantages :

È Additional margin is required because Vs is changed

(depending on power source). (The regulator loss is
caused by margin design).

È Greater core size and condensor capacity are needed,

because the transformer works on a single power
frequency.

Fig. 2-5

2-1-1 (B) SMPS(PULSE WIDTH MODULATION METHOD)

Fig. 2-6

3 Terms

- 1st : Common power input to 1st winding.

- 2d : Circuit followings output winding of transformer.

- f(Frequency) : Switching frequency(T : Switching cycle)

- Duty : (Ton/T) x 100

V

Vreg

Vout

0 t

Change by common power

Regulator loss

Transformer Vout

(Np)

(Vp)

Switch

Vs switch

I switch

Vin

ON/OFF Control

+

–

+

–

+

+

+

–

(Vs)

(Ns)

Regulator

Reference Information

Samsung Electronics 2-3

3 Waveform

Vin

0

t

Fig. 2-7

Fig. 2-11

Fig. 2-8

Fig. 2-12

Fig. 2-9

Fig. 2-10

Fig. 2-13

Vswitch

ON/OFF
Control

0

Ton Toff

f t

0

Iswitch

0

Ton

Toff

Vin–Vp

t

t

Vp

0

Vs

0

Vin

t

Vps

Vout

Vs1

t

Vs2

0

t

Reference Information

2-4 Samsung Electronics

2-1-1(c) INTERNAL BLOCK DIAGRAM

1. Internal block diagram of SMPS circuit

Fig. 2-14

2. PIC1(KA7552) internal block diagram

Fig. 2-15

BIAS

OFF

2.8V

7.0V

CS

8 7

1

CT RT

10UA

OSC UVLD

VCC

OUT

GNDIS(+)

PB

4.3k

3.6V

ZD

G

D MAX

(46%, 70%)

R

S

Q

PWM

OCP

+
Ð

Ð

+

Ð

+

Ð

+

0.24V

6

5

4

3

2

Noise

removal

(SNUBBER)

Smoothing

circuit

Rectified circuit

Line filter

Power IN

(85-265V)

PWM control circuit

(KA7552)

Voltage

detection

circuit

F

E

T

Convertor

FLT driving

circuit

5V rectified

smoothing circuit

3.3V rectified

smoothing circuit

9V rectified

smoothing circuit

8V rectified

smoothing circuit

-8V rectified

smoothing circuit

-8V rectified
voltage

circuit

8V rectified

voltage

circuit

9V rectified

voltage

circuit

3.3V rectified
voltage

circuit

5V rectified

voltage

circuit

Noise removing
circuit at power

input/output

O

u

t
p
u

t

Reference Information

Samsung Electronics 2-5

2-1-2 SMPS circuit description

2-1-2(a) CIRCUIT METHOD

FLY-BACK PWM(Pulse width modulation) control

2-1-2(b) CIRCUIT DESCRIPTIONS

1. AC power rectification/smoothing terminal

- PD01 : Convert AC power to DC(Wave rectification)

- PO10 : Smooth the voltage converted to DC(Refer to Vin of Fig. 2-7)

- PC01, PC02, PC03, PC04, PC05, PC06, PL01, PL02, PL03 : Noise removal at power input/output

- PVA1 : SMPS protection at power surge input

- PVA2 : SMPS protection at 2st ground surge input(PVA1 pattern open : to remove noise)

- PR10 : Rush current limit resistance during power cord insertion.
È Rush current = (AC input voltage x 1.414 - Diode drop voltage) / Pattern resistance + PL02.01

resistance + PC10 resistance + PR10) (AC230V based : approx. 26A)

È Without PR10, the bridge diode might be damaged as the rush current increases.

2. SNUBBER circuit : PR17, PR18, PC11, PD10

- Prevent residual high voltage at the terminals of
switch during switch off/Suppress noise.

High inverted power occurs at switch off,
because of the 1st winding of transformer:
(V=L1xdi/dt. LI : Leakage Induction)
A very high residual voltage exists on both
terminals of PQ1 because dt is a very short.

- SNUBBER circuit protects PQ1 from damage
through leakage voltage suppression by RC,
(Charges the leakage voltage to PD10 and PC11,
and discharges to PR17 and PR18).

- PC12, PL11 : For noise removal

Fig. 2-16

3. PIC1 Vcc circuit

- PR11, PR12, PR13, PR14 : PIC1 driving resistance (PIC1 works through driving resistance at power cord in)

- PIC1 Vcc : PR20, PD12, PC17

1) Use the output of transformer as Vcc, because the current starts to flow into transformer while PIC1 is active.

2) Rectify to PD12 and smooth to PC17.

3) Use the output of transformer as PIC1 Vcc : The loads are different before and after PIC1 driving.
(Vcc of PIC1 decreases below OFF voltage, using only the resistance due to load increase after PIC1 driving.)

- PR20 : For noise removal

0

Vin–Vp

Vswitch

dt

Toff

t

Inverted power
by leakage
inductance