Spindle Circuit - LG GSA-4167B Service Manual

4. Spindle Circuit

4-1-1. Block Diagram(FGCAV Servo)
Disc
Motor unit
SPD
R349
R375
C349
1.65V
4-1-2. FG CAV Servo
1) CD 48x CAV : CD-ROM, CD-R
2) CD 40x CAV : CD-RW
3) DVD 8x CAV : DVD+RW
4) DVD 10x CAV : DVD+R
5) DVD 12x CAV : DVD-ROM DL
6) DVD 16x CAV : DVD-ROM
7) DVD 16x PCAV : DVD+R
When drive read PRESS CD, Closed Session CD-R/RW, the spindle motor is controlled using FG CAV Spindle
Servo. FG signal(R2S30202FP 19pin) input to SFG in DSP IC(R8J32007 213pin).
The spindle controller in DSP IC uses SFG as spindle rotation frequency feedback, therefore the FG CAV
Spindle Servo doesn't work well if FG generation 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, and FG pulse output is generated as 18 pulses/rotation.
53
Optical
Pick-up
HOP-7632TS
IC301
R8J32007
SPD
P M
211
W U
M
X
U
V
W
VCK4M
Control Clock
CAV FD
CAV PD
Motor Kick
REG
12
IC601
13
R2S30202FP
14
CTL2
XCO
Generator
XCI
+
VCK4M
SPIN
1
DAVC
42
1.65
CTL1 20
21
19
FG
X301
33.8688MHz
106
107
SFG
213
R361
3.3V
SPD
CTL1
CTL2
SFG