LG GSA-4167B Service Manual page 50

4-2-1. Block Diagram (Wobble CLV Servo)
Disc
Motor uni t Optical
Pick-up
HOP-7632TS
GND
WBLS H
1.65V
R375
SPD
SPD
R349
C349
1.65V
4-2-2. Wobble CLV Servo
CD-R : 4x, 8x, 16x, 24x, 32x, 40x, 48x
/CD-RW : 4x, 10x, 16x, 24x, 32x
/DVD-R : 2x, 4x, 8x, 16x(PCAV)
/DVD-R DL : 2x, 4x
/DVD-RW : 1x, 2x, 4x, 6x
/DVD+R : 2.4x, 4x, 8x, 12x, 16x(PCAV)
/DVD+R DL : 2.4x, 4x, 6x
/DVD-RAM : 2x, 3x, 3-5x(PCAV)
/DVD+RW : 2.4x, 4x, 8x
When drive write DVD-RAM/R/RW/+R/+RW/CD-R/CD-RW, the spindle motor is controlled using Wobble CLV
Spindle Servo.
The WOBSIG signal(R2S35002 37pin) input to DSP IC(R8J32007 154pin). The DSP Controller in R8J32007
uses WOBSIG as linear velocity feed back, therefore the Wobble CLV Spindle Servo doesn't work well when
WOBSIG signal is abnormal.
The spindle controller PWM output signal SPD (R8J32007 211pin) input to SPIN in Drive IC(R2S30202FP 1pin)
after Low-Pass Filtering.
The PWM output signal U,V, W signal(R2S30202FP 12, 13, 14pin) drives Spindle Motor without using a sensor.
SA
87
SB
S
88
/
SC
89
H
SD
90
MA
92
C171
MB
93
C172
MC
94
C173
MD
95
C174
WBLSH
31
IC301
R8J32007
P M
211
W U
M X
C116
WAG1
18 19
ADO
HPF AGC1
HPF
BCO
BPF
VREF
IC101
R2S35002
Motor Kick
REG
C117 C118
WAG2 WAG3
20
-
+
AGC2
HPF AGC3
+
HPF
-
HPF
WOBSIG
37
154
SP
PH
54