LG GCE-8160B User manual

3
INTRODUCTION
FEATURES
1. General
1) Enhanced IDE interface.
2) Internal 5.25 inch, halfheight CD-R/RW Drive.
3) 2 Mbytes buffer memory.
4) Audio CD like tray loading of a disc without using a caddy.
5) Power loading and power ejecting of a disc. The disc can also be ejected manually.
6) Supports Power saving mode and Sleep mode.
7) Vertical and Horizontal operation.
8) Super Link Function.
2. Supported disc formats
1) Reads and writes data in each CD-ROM, CD-ROMXA, CD-I FMV, Video CD, and CD-EXTRA
2) Reads data in Photo CD (Single and Multi session).
3) Reads and writes standard CD-DA.
4) Reads and writes CD-R discs conforming to “Orange Book Part 2”.
5) Reads and writes CD-RW discs conforming to “Orange Book Parts 3”.
3. Supported write method
1) Disc at once (DAO), Session at once (SAO), Track at once (TAO), Variable packet, Fixed packet, and
Multi-session.
4. Performance
1) Random 110 ms average access time.
2) CD-R Record speed : 4X, 8X, 12X, 16X.
3) CD-RW Record speed : 2X, 4X, 10X.
4) CD-ROM : Max 6,000 KB/s(Max 40x) Sustained Transfer rate.
5) Supports real time error correction and real time layered error correction at each speed.
6) Supports CD-R write operation at each double speed, quadruple speed, eighth speed.
7) Supports CD-RW write operation at double speed and quadruple speed.
8) PIO Mode 4, Multi DMA Mode 2 .
9) Multimedia MPC-3 Spec compliant.
10) Support CD-TEXT read/write.
5. Audio
1) Output 16 bit digital data over ATA interface.
2) 8 Times Digital Filter for CD Audio
3) Software Volume Control
4) Equipped with audio line output and headphone jack for audio CD playback.
5) Front panel Volume Control for Headphone Output.
This service manual provides a variety of service
information.
It contains the mechanical structure of the CD-
R/RW Drive and the electronic circuits in
schematic form. This CD-R/RW Drive was
manufactured and assembled under our strict
quality control standards and meets or exceeds
industry specifications and standards.
This CD-R/RW drive is an internal drive unit
designed for use with IBM PC, HP Vectra, or
compatible computer. It can write as much as 700
Mbytes of digital data into CD-R/RW disc, and can
read as much as 650 Mbytes of digital data stored
in a CD-ROM, CD-R and CD-RW disc.
This CD-R/RW Drive can easily meet the
upcoming MPC level 3 specification, and its
Enhanced Intelligent Device Electronics (E-IDE)
and ATAPI interface allows Plug and play
integration in the majority of today’s PCs without
the need of an additional interface card.

LOCATION OF CUSTOMER CONTROLS
6
1. Disc tray
This is the tray for the disc. Place the disc on the
ejected disc tray, then lightly push the tray (or
push the eject button) and the CD will be loaded.
NOTE: Don’t pull out or push in the disc tray
forcibly. This might cause damage to the loading
section of the drive.
2. Stop/Eject button
This button is pressed to open the CD tray.
This button works only when power is supplied to
the drive.
If an Audio CD is playing, pressing this button will
stop it, and pressing it again will open the tray.
3. Play/Skip button
When an Audio CD is in the disc drawer, pressing
this button will start playing Audio CDs from the
first track. If an Audio CD is playing, pressing this
button will skip to the next track.
4. Emergency Eject Hole
Insert a paper clip here to eject the Disc tray
manually or when there is no power.
5. Volume control
This is used to adjust the output volume of the
headphone jack. It can’t be used to adjust the
output volume for the audio output connectors on
the rear panel.
NOTE : Turn the volume down before turning on
the power. Sudden loud noises can damage your
hearing.
6. Headphone jack
This jack is for connecting headphones or mini-
speakers.
7. Drive activity indicators
Two colored LEDs are used to indicate the
operation of CD-R/RW Drive.
(1) Read
The orange color is displayed when the spindle
motor begins the Spin up operation: accessing
data, reading data, playing Audio, and up loading
tray.
(2) Write
The green color is flashed during disc writing
sessions.
READ
READ
WRITE
WRITE
Headphone Jack
Volume
Control Drive Activity Indicators
Play/Skip Button
Stop/Eject Button
Disc Tray
Emergency Eject Hole
Front Panel

7
1. Power Connector
Connects to the power supply (5-and 12-V DC) of
the host computer.
NOTE : Be careful to connect with the proper
polarity. Connecting the wrong way may damage
the system (and is not guaranteed). Usually this
connector can only be attached one-way.
2. IDE Interface Connector
Connect to the IDE (Integrated Device
Electronics) Interface using a 40-pin flat IDE
cable.
NOTE : Do not connect or disconnect the cable
when the power is on, as this could cause a short
circuit and damage the system. Always turn the
power OFF when connecting or disconnecting the
cable.
3. Jumper Connector
This jumper determines whether the drive is
configured as a master or slave. Changing the
master-slave configuration takes effect after
power-on reset.
4. Analog Audio Output Connector
Provides output to a sound card (analog signal).
Generally you need this to play a regular audio
CD.
5. Digital Audio Output Connector
Provides output to a sound card (digital signal).
Digital Audio Output
Connector
Jumper Connector
Analog Audio Output Connector IDE Interface Connector
Power Connector
Rear Panel

ATIP Absolute Time in Pre-groove. With an additional modulation of the “Wobble”, the “Groove”contains a time
code information.
Wobble The pre-groove in the Disc is not a perfect spiral but is wobbled.
With : –A typical amplitude of 30 nm
–A spatial peried of 54~64 µm
CW Continuous Wave. The laser light output is at a constant level.
DOW Direct Over-Write. The action in which new information is recored over previously recorded information in
CD-RW disc.
Overwrite The action in which new information is recorded over previously recorded information.
(Pre-)Groove The guidance track in which clocking and time code information is stored by means of an FM
modulated wobble.
Land Land is characterized in the following way:
When radial signals are concerned,land is defined as the area between the grooves.
When HF signal are concerned,land is defined as the area between the marks(pits) in tangential
direction.
Hybrid Disc A Multisession disc of which the first Session is mastered. On a hybrid disc, recorded and
mastered information may co-exist.
Mastered Information,stored as pits on the disc during the manufacturing process of the disc.
Information (when making the master)
OPC Optimum Power Control. Procedure is determined optimum recording power according to CD-
R/RW Media in recording start step.
ROPC Running OPC. The purpose is to continuously adjust the writing power to the optimum power
that is required.
When the optimum power may change because of changed conditions of disc and change in
operating temperature.
Jitter The 16 value of the time variation between leading and trailing edges of a specific (I3 …I11) pit
or land as measured by Time Interval Analysis.
Deviation The difference between a fixed value of Pit length and Land length.
TOC Table Of Contents : in the Lead-in Area the subcode Q-channel contains information about the
Tracks on the disc.
Packet A method of writing data on a CD in small increments.
Writing Two kinds of packets can be written : Fixed-length and Variable-length.
Write The shape of the HF write signal used to modulate the power of the laser.
Strategy The Write Strategy must be used for recordings necessary for disc measurements.
Information Wobble, ATIP, Disc Identification, Write Power, Speed Range OPC Parameters, etc are
Area recorded in the Information area of CD-RW Disc
Finalization The action in which (partially) unrecorded or logically erased tracks are finished and the Lead-in
and/or Lead-out areas are recorded or overwritten with the appropriate TOC subcode.
Logical Erase
A method to remove information from a disc area by overwriting it with an EFM signal containing
mode 0 subcode
A logically erased area is equivalent to an unrecorded
Physical Erase The action in which previously recorded information is erased by overwriting with a CW laser
output.
After a Physical Erase action, the erased area on the CD-RW disc is in the unrecorded state
again.
Session
An area on the disc consisting of a Lead-in area, a Program area, a lead-out area.
Multi session A session that contains or can contain more than one session composed Lead-in and Lead-out
GLOSSARY
10

The differences of CD-R/CD-RW discs and General CD-ROM
1. Recording Layer
Recordable CD has a wobbled pre-groove on the surface of disc for laser beam to follow track.
2. Disc Specification
Read-only Disc
CD-R and CD-RW Disc
3~11T
1.6um
0.4~0.5 um
(Pit)Groove
Land
Track pitch(p)
Radial Direction
Iw
A
O
a
a
Groove
Land
Radial Error Signal
The Groove wobble
Average center
Actual center
CD-ROM CD-R CD-RW
Standard Yellow Book Orange Book II Orange Book III
Record Not available Write once Re-writable
I 11/Itop > 0.6 > 0.6 0.55 > M11> 0.70
(HF Modulation)
Write Laser Power(mW) 10-30 mW 6-25 mW
Read Laser Power(mW) < 0.5 mW < 0.7 mW < 1.0 mW
Jitter < 35 nsec < 35 nsec < 35 nsec
Reflectivity (Rtop) 70 % 65 % 15 % ~ 25 %
18
CD-ROM (READ-ONLY DISC) a=30nm

19
3. Disc Materials
1) CD-ROM disc
Laser Beam Groove
Substrate
(Polycarbonate)
Organic Dye Layer
Reflective Layer
Protective Layer
Label Printing
2) CD-R disc
Pigment Reflective Layer Color
Phtalocyanine Gold/Silver Yellow/White
Cyanine Gold/Silver Dark Green/Bright Green
Azo Gold/Silver Dark Blue
•It is composed of Silver _ colored aluminum plate and Reflective layer.
•Groove (Pit) of aluminum plate make a track.
•Laser wavelength : 780 nm, Laser Power (Read): 0.5mW
•Signal is detected by the
difference of reflective beam
intensity between “pit”and
“Land”on the disc.
•It is so-called WORM (Write Once Read Many) CD.
•It is composed of polycarbonate layer, Organic dye layer, Reflective layer, and Protective
layer.Gold/Silver Reflective layer is used to enhance the reflectivity
•According to the kinds of Organic dye layer, it is divided by Green CD, Gold CD, Blue CD.
•Laser Wavelength : 780 nm, Laser Power (read) : 0.7 mW
•Recording Power : 4x(10~15mW), 8x(14~20mW), 12x(15~30mW, 16x(25~35mW)
•When some part of dye layer is exposed to laser heat, it’s color changs black.Therefore, writing and
reading is enabled by the difference of reflectivity between changed part and unchanged part.
•Polycarbonate layer has Pre_Groove which make a Track.
Laser Beam
Pit
Substrate
(Polycarbonate)
Reflective Layer
Protective Layer
Label Printing

20
33))CCDD--RRWWDDiisscc
4. Reading process of Optical Disc
Laser Beam Groove
Substrate
(Polycarbonate)
Reflective Layer
Dielectric Layer(TL)
Dielectric Layer(UL)
Protective Layer
Label Printing
•It is composed of polycarbonate layer, alloy(silver, arsenic) layer, aluminum reflectivity layer, protective layer.
•An crystalized alloy layer is transformed into noncrystalized by the laser heat. Therefore, writing and reading
is enabled by the difference of reflectivity.
•It is possible to overwrite about 1000 times.
•Laser Wavelength : 780 nm, Laser Power (Read) : 1.0mW
•Recording Power : Erase (4~18mW), Write (6~35mW)
•When disc rewriting, new data is overwritten previously recorded data.
•Polycarbonate layer has a Pre-Groove which make a track.
Lens H
D
Beam
Spot
Focusing
Lens
Laser Spot
at Constant
Read Intensity
Reflected
Light
Signal
Laser Spot
Position
(Time)
Previously Recorded Marks
Groove Land Mirror
I3Itop
I11 IGILI0
Numerical aperture: NA = nsin θ ,
n: Refractive index
Focus depth : H=
λ/ NA
laser spot diameter : D= λ/ NA
2
θ

21
5. Writing Process of CD-R Disc
a b c d e f g
a
b
c
d
e
f
g
Incident
Laser
Power (Read) (Read)
(Write)
Laser Spot
Position
(Time)
a b c d e f g Laser Spot
Position
(Time)
Laser
Spot
Recorded
Mark
Reflected
Light
Signal
Reflected
Light
Signal
Below "ORP"–Mark Too Short
At Optimum Record Power ("ORP")
Above "ORP" –Mark Too Long
Time
6. Writing process of CD-RW Disc
Write Power
Erase Power
Read Power
Groove
Crystal Amorphous
Amorphous
Recorded state
(lower reflectivity)
Melting/
quenching
Heating/
gradual cooling
Crystal phase
Erased state
(higher reflectivity)

7. Organization of the PCA, PMA and Lead-in Area
1) Layout of CD-ROM disc
22
Center hole Clamping and Label Area Information Area
Lead-in Area
Lead-in Area
Diameter 15 mm
Diameter 46 mm
Diameter 120 mm
Program Area
Read Only Disc
Lead-out Area
Program Area Lead-out Area
Center hole Clamping and Label Area Information Area
PCA PMA
Test Area Count Area
Diameter 15 mm
Diameter 45 mm
Diameter 120 mm
Unrecorded Disc
Tsl-00:35:65 Tsl-00:15:05 Tsl-00:13:25 Tsl 99:59:74
00:00:00
in out
Test Area : for performing OPC procedures.
Count Area : to find the usable area immediately in T.A
Tsl : start time of the Lead-in Area, as encoded in ATIP
PMA : Program Memory Area
Disc Center
Disc Center
2) Layout of CD-R/RW disc

23
8. Function of PCA and PMA area
1) PCA (Power Calibration Area)
•PCA area is used to determine the correct Laser Power for a disc.
–Method 1 : PCA area is divided by a track.
–Method 2 : The previous Calibration value is referred.
–Method 3 : ROPC is used to determine Laser Power value automatically in data writing.
•CD-R Disc can write maximum 99 Tracks but CD-RW Disc can write unlimited tracks because it has a rewritable
function.
2) PMA (Program Memory Area)
•It has a track information (track No, track Start/End time) of every track before writing completed.
–PMA area has the last written point and the next writable point of a disc.
–In case of CD to CD copy, some writer may not write PMA area.
* When Disc is Finalized,
PMA information is transferred to the Lead_In area so that general Driver can read it.
* Because PCA and PMA area exist before Lead-In area, General CD Player or CD-ROM Drive can’t read
these areas.
9. OPC and ROPC
1) OPC (Optimum Power Control)
•This is the first step of writing process, because CD writer has its own laser power value and media have different
writing characteristics,
–This is determined by the Writing characteristic, speed, temperature, and humidity.
–Laser wavelength is determined by the environmental temperature (775~795nm) and Optical Laser Power is
determined by the test and retry.
•Asymmetry and optimum writing Power
–EFM signal Asymmetry is determined by the writing power.
Therefore, Optical Power which has the same value to the preset power value can be estimated by measuring
HF signal Asymmetry on the PCA area.
•Measurement of Asymmetry
* Parameter setting (Beta) : Using AC coupled HF signal before equalization
Beta = (A1+A2)/(A1-A2)
Time P << Po Time P = Po
HF Signal
A1
0
A2
Time P >> Po

2) ROPC (Running Optimum Power Control)
•Variable primary factor of Optimum Power
–Change of Power sensitivity on the Disc. (limited to 0.05 *Po)
–Wavelength shift of the laser diode due to the operating temperature change.
–Change of the Spot aberration due to the Disc skew,
Substrate thickness, Defocus.
–Change of Disc or Optics conditions due to the long term OPC
==> It is necessary to adjust continuously to obtain the Optimum Power.
•Principle of Running OPC
–To meet the factors mentioned above,
a horizontal _ direction movement of a curve is uesd.
–Beta = f(B-level) = constant on the Recorded Disc
–Procedure of ROPC
a. Reference B-level is determined during OPC Procedure.
b. During Recording, B-level value is controlled to have a close
Reference B-level value.
c. Normalization of B-level is used to eliminate the effect of reflectivity fluctuation.
==> The reflected B-level value is normalized by the disc reflectivity itself.
24
CCDD--RR//RRWWMedia
Write Strategy
Determination
PCA Test Area
Program Area
PMA Area
Lead-In Area
Lead-out Area
OPC
PCA Count Area
ROPC
* Recording Capacity of CD-R/RW (74Minute Recording media)
•(2048 Byte/Sector) X (75 Sector/Second) X (60 Second/Minute) X 74 Minute
= 681,984,000 Bytes = 682 Mbytes
•But the actual recording capacity is about 650 Mbytes. (according to the ISO 9660 standard, approximately
30 Mbytes are used to make directory structure and volume names.)
Incident recording pulse
Reflected recording pulse
Sampled timing B
11T
Sample B-level (Write Power)
Level B
Sampled at timing B
Pwo decided by OPC
Recording Power
Level Bwith Pwo
normalized to recording power
Sample Disc Reflectivity
(Read power)
10. Writing Process of DISC

INTERNAL STRUCTURE OF THE PICK-UP
1. KRS-302B Circuit Diagram
25
1
2
3
4
5
6
1
2
3
4
5
1
2
3
4
5
6
7
8
9
10
11
12 13
14
15
16
17
18
19
20
21
22
23
24
12
11
10
9
8
7
10
9
8
7
6
R3
VR1
R2
C5
C3
C6
LD
A
11
C
C4
R1 L1
L2
R5
R6
R7
C7
R8
R4
C10 C9 C8
Vcc
2 Axis Actuator
IC1
PDIC
IC2 FPDIC
C1
C2
GND
G
D
C
E
RF
GND
H
A
B
F
Vc
GND
GNDGND
VccVc
BinOUT
PDIN
VOUT
VCC
VREF
VCC
GND
IOUT
IINR
IOUT
IIN2
GND
IIN3
GND
RFREQ
RAMP
GND
ENABLE
GND
OSCEN
WEN3
VCC
WEN2
GND
GND
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
6
5
4
3
2
1FCS -
TRK -
TRK +
FCS +
GND
PDGND
F
B
A
H
PDVCC
PDVC
G
D
C
E
RF SUM
FPDVCC
FPDVC
FPDGND
FPDO
VCC
VCC
VRDC
VWDC2
VWDC1
GND
GND
OSCEN
WE2
WE1
ENBL
IC3
LD
Driver

2. Signal detection of the P/U
1) Focus Error Signal ==> (A+C)-(B+D)
This signal is generated in RF IC (IC401 : MT1506) and controls the pick-up’s up and down to focus on
Disc.
2) Tracking Error Signal (DPP Method) ==> {(A+D)-(B+C)}- k x {(F+H)-(E+G)}
This signal is generated in RF IC (IC401 : MT1506) and controls the pick-up’s left and right shift to find to
track on Disc.
3) RF Signal ==> (A+B+C+D)
This signal is converted to DATA signal in DSP IC (IC301 : MT1505).
26
Pick-Up module
Photo Diode Tracking
Focusing
Infrared Iaser
k[(F+H) - (E+G)]
(A+D) - (B+C)
(A+D) - (B+C) - k[(F+H) - (E+G)]
Offset
TE
Tp
Sub2
Main
Tp/2 Sub1
Track Center
F,E
D,C
A,B
H,G

DESCRIPTION OF CIRCUIT
1. ALPC (Automatic Laser Power Control) Circuit
1-1. ALPC Loop Circuit
27
2Vref
IC403
FPDO PN401 (P/U)
IC401 MT1506
VWDC2 VWDC1
VRDC
RLDON
WLDON
FVREF
RLDON
RDACX
FPDOX
FPDOX
VRDCO
VRDCO
VRDCX
VWDC1X
VWDC1B
VWDC2B VWDC2X
VRDCB
VRDC
RREFX
VRDCBSEL
(Level Shift to 2’FVREF)
WDAC1X
WREF1X
RREFX
FVREF
RWMODE
RDAOUT
VRDCG
RDAC
8
8
"L"
8"H"
VBDAC
RDACRG
WDA1OUT
RDAON
RREFON
Level Shift
to 0.5V
"L"
"L"
"L"
"H"
"H"
"H"
"L"
"L"
"H"
"H"
"H" : short "L" : open "H" : short "L" : open "H" : short "L" : open
"H" "L"
"H" : short "L" : open
"H" : short "L" : open "H" : short "L" : open
FPDO
RFPDSH
WFPDSH
RLDON 26
27
29
21
21
26
24
28
RFPDSH
WFPDSH
IC201
MT1501
WLDON
10K 4.7K
73 72 19 20
29 20 28 27 26 25 24 23 22 21
54 53
M1
M1
FPDO
M2
M2
M2
VWDC10
M2
M2
M2
M2
D
RREF
V WDC1G
W1DAC
WDAC1G
10
10
RWMODE
WREF1ON
Level Shift
to GND
Level Shift
to GND
S/H
S/H
S/H
WDAC2
WDAC1
VRDC
VRDCN
FPDO
VRDC
RREF
VWDC1N
VWDC1
WREF1
VWDC2N
VWDC2 WREF2
VWDC1
VRDCG VRDCG
VRDCG
x1/x2
x1/x2
x2, x4, x8, x10
FPDOG
VRDCDAG
VWDC2G
WAPC2ON
WDA2OUT
WAPC2ON
WAPC2ON
W2DAC
WDAC2G
VWDC1
WREF1X
"L"
"H"
"L"
"H"
VWDC2
WREF2X
VWDC2
WREF2X
WLDON
WLDON
WLDONDLY
WLDON
WDAC2X
WDA1ON
WDA2ON
WDA2SEL
WREF2ON
M2
WREF1
M2
WREF2
VWDC1B
RDAC
VWDC20
M2
FPDOG
Gain
VRDC1DAG
VWDC2DAG
Gain Gain
VRDCDA
0V-VWDC1B
256 Steps
VWDC1DA
0V-VWDC1B
256 Steps
VWDC2DA
0V-VWDC2B
256 Steps
34
VWDC10
33
VWDC20
32
Digital
CKT
(AUX-6)

1-2. ALPC(Automatic Laser Power Control) Circuit Operation
ALPC (Automatic Laser Power Control) function in CD-R/RW analog front-end is for constant power level
control purpose. Based on the accurate power sensor(FMD) in PU, APC feedback loop maintains constant
power level against laser diode’s temperature variation.
There are three power control loops in CD-R/RW analog front-end, which are used with different
combination for different applicatioins. Generally, the first APC loop is used for read power control. The 2nd &
3rd APC loop is used for write (or erase) power control for CD-R/RW disc.
The first APC loop amplifies (up to 10x) the FMD signal (FPDO) to enhance the accuracy of read power
control. VRDCG is used to adjust the gain of FMD signal. The built -in 8-bit RDAC is used to set the read power
level.
The 2nd & 3rd APC loop is used for high power control. Both WDAC1 and WDAC2 are 10-bats DAC,
which are used to set the wanted power level. The 3rd APC loop can alos be used as a voltage divider, which
take input from 2nd APC loop (VWDC1B).
Besides, three 8-bit potentiometers (VRDCDA, VWDC1DA, and VWDC2DA) and amplifiers (VRDCDAG,
VWDC1DAG, VWDC2DAG) are used to speed up the transient response of VRDCO, VWDC1O, VWDC2O.
On the other hand, the input signal FPDO after amplification (x2 or x4) will send the MPXOUT2 for
monitoring.
28

2. RF Amplifier Circuit
Block Diagram
29
150KHz
150KHz
150KHz 150KHz
(A+C)-(B+D)
K1*(A+C)-(B+D)
FE
FEI
K2*[MPPO-SPPO]
K*E+F+G+H)
A,B,C,D
LPF
(40kHZ)
LPF
(40kHZ)
Gain
Fix
MPPO
MPPO
SPPO
SPPO
TEOS
E,F,G,H
IC401 MT1506 IC301
MT1505
Pick up
KRS-302B
IC201
MT1501
Offset adj
9 8
15 14
16
7
13 10
95
10 122
96 97 98
2 3 4 5
LPF LPF
ADD MPPG
LPF LPF
GAIN
ADD
LPF
x1
x1/x2
ADD
x1/x3
Offset adj
EQRF
Filter
VGA
Offset adj.
Data Slicer
Offset adj
Offset
adj
HPF AGC1/2
Gain
Adj
Gain
Adj
Gain
Adj
Gain
Adj
Gain
Fix
Gain
Fix
CE/MPP
CEI
11 121
TE
TEI
12 120
SBAD
SBAD
14 118
EQRF
RFIS
RFI
88 123
124
ATFG
ATFM
ATFG
60 50
41
LPF
(40K/80K/160K
/320KHz)
LPF LPF AGC3
HPF
VREF
BPF
(22.05KHz)

3. Focus/Tracking/Sled Servo Circuit
3-1. Focus, Tracking & Sled Servo Process
30
Focus, Tracking Servo
CB
DA
E
F
G
H
Pick- up
A,B,C,D,E,F,G,H A,B,C,D
Focus Error
Detector
Track Error
Detector
A,B,C,D
E,F,G,H
IC401 MT1506
FE
TE
TE FE
A/D
PARALLEL
DIGITAL
COMPENSATOR
DAC
SLED
COMPENSATOR
STEP1
STEP2
IC301
Servo Control
MT1505
Tracking x5
Focus x5
Tracking Focusing
Actuator
FEO
TEO
F+
F-
T+
T-
Sled Control
M
Stepping Control
Logic
SL1+
IC501
M63024FP
SL1-
SL2-
SL2+
IC501 M63024FP
27 115
28 114
108 107
1
2

3-2. Focus Servo
The aim of Focus Servo is to maintain the distance between object lens of P/U and disc surface, so that
the detected RF signals (A, B, C, D) can be maximized.
Focus Servo is based on focus error (FE) signal which is generated from focus error detection block in
MT1506(IC401) using Astigmatism Method. Focus gain and path can be changed at the MT1506
according to the disc, and the resulting output (FE) is input to Servo IC (IC301, MT1505).
FE signal after first amplification in MT1505 is A/D converted and input to Digital Equalizer Block, most
important part at the Focus Servo. At the Digital Equalizer, adjustments for Focus Bias and Loop Gain are
performed.
After D/A converted, Focus servo signal is output through FOO port (MT1505, Pin115) and drive Focus
Actuator through the Focus Drive IC (IC501, M63024FP).
3-3. Tracking Servo
The aim of Tracking Servo is to make laser beam trace the data track on disc. Tracking Error (TE) signal
is generated from tracking error detection block in MT1506 (IC401) using DPP (Differential Push-Pull)
Method. DPP method uses not only main beam (A, B, C, D) but side beams (E,F and G, H) for correcting
DC offset generated in Push-Pull method.
The remaining procedures of TE signal processing in MT1505 is similar to Focus Servo.
After D/A converted, Tracking servo signal is output through TRO port (MT1505, Pin114) and drive
Tracking Actuator through the Tracking Drive IC (IC501, M63024FP).
3-4. Sled Servo
The working distance of tracking actuator is too short to cover whole disc radius. Sled Servo make PU
move by little and little so that the laser beam keep tracing the data track on disc continuously when
tracking actuator reaches the working limit.
Another function of Sled Servo is to seek a target point on disc, following user commands.
Sled control signal, STEP 1, 2 is generated in MT1505. STEP 1, 2 are output to sled motor via IC501
(M63024FP).
31

4. Spindle Servo Circuit
4-1. Spindle Servo Process
4-2. Spindle Servo
Spindle servo is as followings;
1) Wobble CLV x2, x4, x8, x10, x12, x16 : Blank area in CD-R, CD-RW.
2) CD 15x CAV: Eccentric CD-R/RW.
3) CD 20x CAV: Video CD, CD-DA in CD-ROM/R
4) CD 32x CAV: Recorded area in CD-RW.
5) CD 40x CAV: CD-ROM. Recorded area in CD-R.
–Spindle Servo is controlled by IC201 (MT1501), IC301(MT1505) and servo signal is output via WDMO
(IC201 pin74).
32
CB
DA
E
F
G
H
Pick- up IC401 MT1506
Wobble Signal
Generator
RF
SRF
ATFG
Data PLL
Spindle Control
PWM
EQRF
CD EFM
CLV
CAV x40
Hall Sensor
M
Spindle Motor
IC301
MT1505
IC201 MT1501
IC501 M63024F
6
8
IC510 BA6664FM
WDMO
RDMO
FG
Divider
Wobble Spindle
CLV Control
PWM
106
60
88
124
110
7341
7426
824
120
MATRIX
Current comp.
CTL amp.

74
Optical Pick-up KRS-302B
PD
VWDC
VRDC
Spindle Motor
FCS TRK
SLED DC Motor
Writing
Strategy
DMO Try control
Address/Data
FEO
TEO
SLO
Servo S/H,
Write S/H Signal
Wobble FG/EFM
Address/Data
RFAC, RFDC, FEI, TEI
Data
Laser Power Ref.
IC203
AT93C86
2KB
EEPROM
IC302
39SF020A
256KB
Flash ROM
IC401
MT1506E
RF Amp
Wobble
ALPC
DAC
IC301
MT1505E
DSP
Servo
Audio
34.57MHz
IC201
MT1501E
DECODER ENCODER
ATIP Demodulator
Write Strategy
Write S/H Singnal
I/F
Data IC202
2MB
SDRAM
H O
S
T
5V
12V
I/F
Cable
Audio
Mute
Circuit
L,R
Line Out
Audio
L,R
IC501
M63024FP
5Ch Servo DRIVE
3.3V
Reset
BLOCK DIAGRAM
FUNCTIONAL BLOCK DIAGRAM