Samsung SDR430 Circuit Descriptions
3. General information
3-1. Circuit description
3-1-1. Front
3-1-2. Rear
Earphone
jack
Up/Down
Volume
LED Disc tray Emergency
Figure 3-1
Stop/ Open
button
HOLE
Digital output
terminal
(Optional)
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Sound output
terminal
Master/Slave
select pin
Interface terminal
Figure 3-2
Power terminal
3-1
3-2. Circuit description
3-2-1. RF
3-2-1(A) RIC1(TA1293F)
RIC1(TA1293F)is used in combination with TC 9453F as bipolar IC developed for CD/DVD RF signal
system. In main, it receives the pick-up output converted into I/V and performs DVD waveform equalization(EQ), CD equalization(EQ), astigmatic focus error signal generation, 1-beam tracking error
signal generation(by DPD method), 3-beam tracking error signal generation FE TE RF GAIN adjutment and laser power control, etc.
1) Reference potentiometer
RIC1 selects a single power method and from pick-up input singnal terminl works on the basis
VrA of 2.1.V.
2) CD/DVD-RF signal system : RICL(TA1293F)
Figure 3-3 shows the flow of RF signal generated in pick-up.
¡Ü EQ control parameter
1. EGF(58pin) : Change the peak frequency with EQ frequency features.
(Convert PWM signal, (C9453F(168-pin) into DC via low-pass fiter and supply it.)
2. EGF(57pin) : Change the boost of EQ frequency features.
3. VRCK(17pin) : Input the base clock and link the peak frequency witt it.
4. EQD(24pin) : Change the group delay characteristics with EQ frequency features.
CD/DVD play signal is equalized according to the above control parameter setting and output to
RFD(45pin) and this signal is transferred to TC9453F and detected as digital signal.
3-2
Figure 3-3
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Circuit description
3-3-3. SERVO circuit description
3-2-2(A) Outline
SERVO system of DVD is divided into FOCUS SERVO, TRACKING SERVO, STEP MOTOR LINKED SERVO
and SPINDLE MOTOR CONTROL SERVO.
1) FOCUS SERVO
Focus the optical spot outputted from object lens on disc surface correctly by maintaining a regular distance beween object lens of Pick-up and disc for surface vibration of disc.
2) TRACKING SERVO
Make the object lens follow the disc track in use of tracking error signal created from Pick-up.
3) STEP MOTOR LINKED SERVO
When the tracking actuator inclines to outer as the object lens follow the track at play, move
STEP motor a little. and prevent it from leaning.
4) SPINDLE MOTOR CONTROL SERVO
Control the disc motor to maintain a constant angular velocity in use of FG signal outted in Drive
IC.
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3-3
Circuit description
3-2-2(B) SERVO SYSTEM BLOCK DIAGRAM
3-4
Figure 3-4
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Circuit description
3-2-2(C) Operation descriptions
1) Focusing SERVO
(1)Focus input
The focus loop is changed from open loop to close loop. The triangular waveform moves the object lens up and down in 158pin terminal of SIC1 at Focus SERVO ON. At that time, S curve is
inputted to 150 pin terminal of SIC1. SBAD (152pin terminal of SIC1) signal, summing signal of
PD A, B, C, D, is gernerated at occu rrence of S curve and zero cross(1.7V)point is found by S
curve and focused on when SBAD signal exceeds a regular value. The focus loop is changed into
close loop and the object lens follows the moving of disc, maintaining a regular distance with disc.
While, this operations are same in CD and DVD.
158pin terminal of SIC1(FOO)
150pin terminal of SIC1(FEI)
152pin terminal of SIC1(SBAD)
Figure 3-5
(2)Play
When focus loop gets to close loop at focus servo on, both 150pin and 158pin terminal of SIC1
are contolled by Vref voltage(approx.1.7V)and focus on cascade on the disc up and down.
Verf
Verf
1V
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3-5
Circuit description
2) TRACKING SERVO
¢Å NORMAL PLAY MODE
(1)For DVD
Make the signal outputted though PD A, B, C, D of Pick-up, tracking error signal in use of phase
difference of A+C and B+D in RIC1and inputted to SIC1151(TEI) terminal. This signal is outputted to SIC1 159 terminal(TRO) via digital equalizer and impressed to tracking actuator through
DIC1. SIC1 159 terminal is contolled in Vref(approx 1.7V)at normal play.
(2)For CD, VCD
Reccive the signal outputted though E,F of Pick-up, from RIC1, differently from DVD and make
the tracking error signal though RIC133pin terminal.
¢Å SEARCH MODE
Search mode is divided into fine seek, moving the tracking actuator a little and coarse serch, moving
much in use of STEP motor. The coarse search will be described in STEP linked servo and now, the fine
seek is explained shortly. If the object lens is located near target, cut off the tracking loop and
give the control signal as many as desired count to move the tracking actuator via SIC1 159pin terminal(TRO).
3) STEP LINKED SERVO
¢Å NORMAL PLAY MODE
During the play signal come from 162pin of SIC1 where according to movement of the tracking
actuator along the track, and the signal is turn into terminal 50 of micom.
¢Å COARSE SEARCH MODE
After making seek lead the track make search for ID , and check up the number of must-go-track, in
case the remaining track is within the extend of fine seek, move the fine seek to object track. In
case pick up move in the long distance, the step motor move to half-step use the profile of must-go
velocity in micom(MIC1).
4) SPINDLE MOTOR CONTROL SERVO
The FG is generated DIC2 39terminal rotation of disk, and this signal is inputted SIC1 175terminal
where is outputted SIC1 163terminal with ckeck up velocity.
This signal is supplied in DIC2 25terminal where control velocity of rotation at disk. The disk is
rotated standard angular velocity(CAV FORM) without relations of the inside and the outside of
circumference of pick up.
3-6
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