4
1.2.3 Tracking / Slider Servo
ATB: The tracking balance compensation is
achieved by outputting the offset from
the TBAL output at pin 46 of the digital
servo IC, and by biasing the charge pump
resistor for phase-difference error of
RFIC.
The difference is detected by processing
TE at pin 34 of IC 201 with an internal
digital equalizer.
TDO: In addition to the servo output, the low-
band components, such as the kick-brake
for jump, are added for TDO output.
SLDO: The low-band components of TE are
processed by the internal digital
equalizer, and deadband is added for
SLDO output. The offset voltage for
pickup movement is also included in the
SLDO output.
4
34
46
50
24
26
27
16
17
47
5
6
7
8
OEIC
PICKUP
IC101
RFIC
IC201
DIGITAL
SERVO IC
IC501
MECH.
CONTROL
IC151
DRIVER
• TRACKING / SLIDER SERVO
TE
TE RF
B1
B2
B3
B4
TRKG
COIL
TBAL
ADDRESS
&
BUS
TDO
19
SLDO
M
26
28
CP
SLDR
3
12
41
57
48
25
95
OEIC
IC101
RFIC
IC301
A/D
IC701
LSI II
IC201
DIGITAL
SERVO
IC161
DRV
• SPDL SERVO
RFO
RF
CLK
(27M)
8 bit
ATC
APC
AFC
ASC
V165
DUTY50
FG
VPWM
PPWM
RPWM
FPWM
31
50
32
RF
IC302
(1/2)
IC271
(2/2)
IC271
(1/2)
FG
SPDL +
SPDL -
SPDL
SPDO
(Base)
SPDO
(Compatible)
3
|
10
200
|
207
179
176
178
180
177
161 163 166 167
159
VCO
12
13
M
1.2.4 SPINDLE SERVO
For a CD, the RF signal output from pin 32 of the RF IC is converted
to binary in IC201. By comparing the binary value with the reference
CLK (clock), the SPDL ERR signal is output from pin 48.
For a DVD, the SPDL ERR signal is generated from the PWM signal
output from LSI-
ΙΙ
. Upon receiving this signal via pin 31, IC201
also outputs it from pin 48, switching from the CD SPDL ERR
signal.
