3
CX-3311
5
6
7
8
5
6
7
8
A
B
C
D
E
F
FE = (FE1) - (FE2)
After 10 bit ADC
21
20
FE2
FE1
CN1101
115
116
VIN7
VIN8
LPF
50k Hz
Input AMP
LPF
Buffer
LPF
50k Hz
G=0 dB
Buffer AMP
ADC drive AMP
Gain switching
6 dB, 7.5 dB, 9 dB, 10.5 dB
ADC
Selector
Selector
ADC
Gain switching
Gain switching
-6 dB, 0 dB, 9.5 dB
FE1
FE2
FE signal generating circuit
+
-
1+Pfbal0,1/0x0100
1-Pfbal0,1/0x0100
Offset Cancel
Fbal coarse
adjustment value
FE
AMP
3 dB, 9 dB
1.1.2 SPDL Circuit
For the SPDL motor for the DVD mechanism module, a brush motor which is used for the CD mechanism module is adopted
instead of a brushless motor which is used for the conventional DVD mechanism module.
The SPDL circuit to drive the brush motor is as shown below.
IC1501
MN2DS0018MA
66
MD
26
OPIN3-
25
OPOUT3
16
VO3-
15
VO3+
MOTOR
IC1251
MN2DS0018MA LSI
MN2DS0018MA LSI
1.1.3 FE Generating Circuit
Focus Error (FE) Generating Circuit
Signals FE1 and FE2 from PU will be AD converted and imported to IC1501. Then, taking the offset cancel into
consideration and taking the differential, FE is generated.