Page 1
CX-3078 2
1234
1234
C
D
F
A
B
E
+
++ +5V
+5V
MD
0.25V 0.5V 0.59V 0.18V
0.22VCDLD0CDLD1CN1101
24
5
26
7 LPCO2
PU unit LDONCD
LDPOWER
LDONDVDLPC23.9-¦3.9-¦3.9-¦3.9-¦
- +
0.17V0.25V 0.18V
+5V
DVDLD0DVDLD1
LPCO1
LPC13.9-¦3.9-¦3.9-¦3.9-¦
- +
-
+
-
+
Reg.
78LD
CD
LDDVD
LD 78MD
65LD
65MD
1 Front End Part (MN35103UB, MN35104UB:IC1501)
MN35103UB and MN35104UB are 1-chip LSI for DVD-Player. The connection of this LSI to the Driver IC,
SDRAM, Flash-ROM, Audio-DAC, etc. can configure the DVD-Player System.
This LSI contains Front End (SODC/FE) that performs RF signal /Servo /Decode processings, Back End
(AV decoder/BE) that performs the video decode processing such as MPEG1/MPEG2/JPEG and audio decode
processing such as DVD-Audio/AC-3/DTS/MP3, and the system controller (Siscon) for controlling the system.
Front End part realizes the arithmetic processing of optical head signal and RF signal processing,
the digital signal processing for DVD-ROM reproduction that conforms to DVD standards (16-8 Demodulation,
Error correction), the digital signal processing for CD-DA/CD-ROM (Error correction), AV decoder transmission,
servo control, spindle motor control and seek control.
Please take note that, since (FEP) and (SODC) with DVD mecha-module (MS3) of CX-3016 are integrated into
one chip at MN35103UB and MN35104UB, the waveforms of servo system on the front end which had
previously appeared at MS3, i.e., the waveforms of FE, TE and AS, cannot be seen anymore.
1.1 Analog Block (MN35103UB, MN35104UB:IC1501)
The analog block for IC1501 generates the servo signals including focus and tracking, processes addition of
RF signals, and controls the laser power of pickup.
The servo system contains focus operation amp, focus offset adjustment circuit, 3-beam tracking operation amp,
phase difference tracking detection circuit, tracking offset adjustment circuit, TE2 value-making circuit.
Also, RF signal processing system contains the functions of AGC and equalizer.
1.1.1 APC Circuit
The optical output for the laser diode (LD) has large minus temperature characteristics. Therefore, the constant
optical output cannot be obtained when LD is driven by the constant current. APC circuit controls the electric
current so as to provide constant output at the monitor diode (MD). MN35103UB and MN35104UB contain two
types of APC circuits, one for DVD and another for CD. The LD electric current for DVD (CD) can be obtained by
dividing the voltage measurements between DVDLD1 (CDLD1) and 5V by 15.6 (3.9 4=
15.6 ). For DVD (CD),
the results are approx. 26mA (44mA).
1. CIRCUIT DESCRIPTIONS
Page 2
CX-3078
3
5 678
567
8
C
D
F
A
B
E
-
++
OFFSET ADJ
1+(Pfbal/0x10000)
1+(Pfbal/0x10000)
1-(Pfbal/0x10000)
Analog block
Servo block
FE+
Pfepofs
-
++
OFFSET ADJ
FE-
Pfenofs
1+(Pfbal/0x10000)
1-(Pfbal/0x10000)
1+(Pfbal/0x10000)
1-(Pfbal/0x10000)
+ VIN6
15- 92
+ VIN7
13- 93
+ VIN8
11- 94
+ VIN5
16- 91
CN1101
B4 B3
B2 B1
-
Dfesv
FE x1 or x4
-
++
OFFSET ADJ
Analog block
Servo block
TE+
Pfepofs
-
++
OFFSET ADJ
TE-
Pfenofs
+ VIN2
15- 96
+ VIN3
13- 97
+ VIN4
11- 98
+ VIN1
16- 95
CN1101
B4 B3 B2 B1
-
Dfesv
TE x1 or x4
-+
-+
-+
-+
EQ
EQ
EQ
EQ
PC
PC
-
++
OFFSET DAC
Analog block Servo block
TE+
Pfepofs
-
++
OFFSET DAC
TE-
G
G
Pfenofs
+ VIN9
VREFH20 k-¦
VHALF 17-
CN1101
A
-
Dfesv
TE -6dB 15dB(3dB STEP)
-6dB 15dB(3dB STEP)
30kHz
30kHz 0dB/12dB
0dB/12dB
+ VIN10
VREFH20 k-¦
VHALF 10- C
1.1.2 FE Generation Circuit
Focus Error (FE) Generation Circuit
Each of input signals from B1 to B4 which had been quartered by PU within the analog block is input to IC 1501
passing through the resistance and becomes a signal of FE+=
-(B1+
B3) and FE -=-(B2+
B4) after adding a focus
offset adjustment value. Then, the signal is AD-converted within the servo block and adds an offset cancel value
to become FE, generating a signal of FE=
(FE+
)
-(FE -).
1.1.3 TE Generation Circuit
Trackings Error (TE) Generation Circuit
For DVD, TE is generated, with the application of a phase contrast method, from the phase difference of (B2+
B4)
and (B1+
B3). For CD, TE is generated, with the application of a 3-beam method, by sending the signal to the
variable amp set for the tracking offset adjustment via outer-attached resistance and then by AD-converting it to
make the formula of TE=
A
-C.
DVD (TE from phase difference)
CD (3-beam TE)