SONY DI5510 Service Manual
TECHNICAL THEORY
FOR SERVICING
DISCMAN
POWER SUPPLY CIRCUIT
OPERATION MANUAL
[photo: D-E705]
COMPACT DISC
COMPACT PLAYER
Contents
1. POWER SUPPLY CIRCUIT CORRESPONDENCE TABLE ·················································································································· 3
2. OPERATION OF THE D-E705 SERIES POWER SUPPLY CIRCUIT ···································································································· 4
2-1. Types of Power Supply········································································································································································ 4
2-2. Identifying the Power Supplies ··························································································································································· 4
2-3. Circuit Voltage ····················································································································································································· 5
2-4. Charging Circuit ·················································································································································································· 15
2-5. APC Circuit ························································································································································································· 19
2-6. ESP (Electronic Shock Protection) Circuit ·········································································································································25
3. OPERATION OF THE D-365 SERIES POWER SUPPLY CIRCUIT ······································································································ 26
3-1. Types of Power Supply········································································································································································ 26
3-2. Identifying the Power Supplies ··························································································································································· 26
3-3. Circuit Voltage ····················································································································································································· 27
3-4. Charging Circuit (Operation of the CHARGE MONITOR IC403) ···································································································· 35
4. OPERATION OF THE D-245 SERIES POWER SUPPLY CIRCUIT ······································································································ 36
4-1. Types of Power Supply········································································································································································ 36
4-2. Identifying the Power Supplies ··························································································································································· 36
4-3. Circuit Voltage ····················································································································································································· 37
4-4. Charging Circuit ·················································································································································································· 47
5. APPENDIX: TYPES AND APPLICATIONS OF SECONDARY BATTERIES FOR PORTABLE EQUIPMENT
(RECHARGEABLE BATTERIES) ··························································································································································· 48
5-1. Nickel-Cadmium Rechargeable Battery·············································································································································· 48
5-2. Nickel-Hydrogen Rechargeable Battery·············································································································································· 55
5-3. Lithium-Ion Secondary Battery··························································································································································· 59
— 2 —
1. POWER SUPPLY CIRCUIT CORRESPONDENCE TABLE
Table 1-1 shows the power supply circuit correspondence table. This new technical theory for servicing shows the power supply block
diagrams of the following models among the respective power supply circuit series.
• D-E705 series power supply system n D-E705
• D-365 series power supply system n D-365
• D-245 series power supply system n D-245
However, among the D-245 series models, those that do not have the ESP circuit do not have the D-RAM IC drive voltage generator
circuit which is described here in chapter "4. OPERATION OF THE D-245 SERIES POWER SUPPLY CIRCUIT."
Table 1-1 Power supply circuit correspondence table
Power supply circuit series
D-E705 series
D-365 series
D-245 series
Model names
D-E700/E800
D-E705/E805
D-263/265
D-365/375/368/369CK
D-465/475
D-E500/E504
D-140/141/143/141CK/142CK/144K/145/147CR/148CR
D-150AN/151/151C/151V/152CK/152CKT/153/155
D-162CKC/162CKT
D-240/247/242CK/242SK/242CKT/243CK/245
D-330/340/345
D-451SP
D-835K/837K/838K/840K/842K/844K/848K
Reference pages
pages 3 to 25
pages 26 to 35
pages 36 to 47
— 3 —
2. OPERATION OF THE D-E705 SERIES POWER SUPPLY CIRCUIT
2-1. Types of Power Supply
The D-E705 series compact CD player can be operated on the following three types of power supply.
♦ DC power supply
• AC adapter .............................................................................. 4.5 V (supplied)
♦ Battery
• Dry cell battery (size AA, 2 pcs).............................................. 3.0 V (optional), or
• Rechargeable nickel-hydrogen battery (NH-DM2AA)........... 2.4 V (supplied)
2-2. Identifying the Power Supplies
When the system controller IC801 is started up, it identifies from where the main power voltage is supplied. It also stops operation
if batteries that do not satisfy the specifications are used. The system controller IC identifies the power supplies from the following
three detections.
(1) Pin %¶[DCINMNT] : The voltage that is obtained by dividing the DCIN input voltage by the resistors.
(2) Pin %•[BATMNT] : The voltage that is obtained by dividing the battery terminal voltage by the resistors.
(3) Pin ^¡[CHGMNT2] : The voltage from the rechargeable battery detection terminal
("H": When the supplied rechargeable battery is inserted)
Table 2-1 Power supply identification table
Pin %¶[DCINMNT]
DC supply (from AC adapter)
Battery Rechargeable battery
Dry cell battery
* 2-1: When a rechargeable battery is inserted, the input of Pin ^¡[CHGMNT2] goes high.
H
L
L
Pin %•[BATMNT]
H
H
H
Pin ^¡[CHGMNT2]
L (H
*2-1
)
H
L
— 4 —
2-3. Circuit Voltage
3[V]
REGULATOR
DCIN
IC401
POWER CONTROL
2.75[V]
DC-DC CONVERTER
IC401,T401,Q403,Q405
12[V]
REGULATOR
IC504
COIL/MOTOR DRIVE
1 VIN VOLTAGE
2 VCPU VOLTAGE
3 VCC VOLTAGE
4 VG VOLTAGE
12[V]
2.75[V]
3[V]
DC VOLTAGE
or
BATTERY VOLTAGE
BATTERY
SERIES
REGULATOR
Q414,Q402
D407
Fig. 2-1 Power supply voltage generation block diagram
During AC adaptor drive operation, the following four outputs of the power supply voltage are generated. (Refer to Fig. 2-1.)
1 VIN voltage
• The external voltage input to the DC jack is regulated by the SERIES REGULATOR (Q414, Q402), passed through D407 and output
as the VIN voltage (approx. 4.5 V).
• When the Discman is operated on battery, the battery terminal voltage is supplied as the VIN voltage.
2 VCPU voltage n "POWER CONTROL IC401"
• This voltage is used for driving the system controller IC801, and is 3.0 V.
3 VCC voltage n "2.75 V DC-DC CONVERTER (POWER CONTROL IC401, T401, Q403, Q405, etc.)"
• This voltage is used by the RF AMP IC501, DIGITAL SIGNAL PROCESSOR IC502, COIL/MOTOR DRIVE IC504, etc., and is 2.75 V.
4 VG voltage n "COIL/MOTOR DRIVE IC504"
• This voltage is used by the POWER CONTROL IC401, etc., and is approx. 12 V.
Generation of the respective voltages is described below.
1. Generation of VIN Voltage
When the DC plug of the A C adapter is connected to the DC jac k, the input v oltage is regulated by the SERIES REGULATOR (Q414 and
Q402), passed through D407 and is output to the POWER CONTROL IC401 and others as the VIN voltage.
— 5 —
2. Generation of VCPU Voltage
The VCPU voltage generation circuit block diagram is shown in Fig. 2-2.
(1) AC adapter drive operation.
When the DC plug of the A C adapter is connected to the DC jack, the SERIES REGULATOR (Q414, Q402) is turned on and so the VIN
voltage (approx. 4.5 V) is sent to pin#º [VIN] of the POWER CONTROL IC401 via D407, which starts up IC401. The VIN voltage is
also sent to pin@™ [VDO] of the POWER CONTROL IC401 via D404. As the POWER CONTROL IC401 is started up, the VCPU
voltage 3.0 V is generated by the SERIES REGULATOR inside IC401. The VCPU voltage thus generated is sent from pin @º [VCPU] to
pin1 [VDD] and pin$¶ [VDD] of the system controller IC801 to start up the system controller IC801. The POWER CONTR OL IC401
has a built-in step-up/step-down regulator, but the step-up circuit inside IC401 is not used in AC adapter drive mode because the volta ge
of 3.3 V or higher is input to pin@™ [VDO] of IC401 all the time. (The switching waveform is not output from pin@¡ [SW] of IC401.)
(2) Battery drive operation
When the battery is inserted, the battery voltage is sent to pin#º [VIN] of the POWER CONTROL IC401 as the VIN v oltage to start up
IC401. As IC401 starts up, IC401 measures the input voltage at pin@™ [VDO]. IC401 has a built-in VDO voltage detection circuit. If
IC401 detects that the input voltage to pin@™ [VDO] is less than 3.3 V, the PNM wave *
2-2
is generated by the SYSTEM CONTROLLER
section inside IC401 and so the switching waveform is output from pin@¡ [SW]. IC401 maintains the input voltage of pin @™ [VDO] to
3.3V or higher by the self step-up circuit consisting of the switching output from pin@¡ [SW], L401, D404 and C439 at all times. On the
other hand, the input voltage to pin@™ [VDO] of the POWER CONTROL IC401 is sent to the SERIES REGULATOR inside IC401 to
generate the VCPU voltage 3.0 V. The VCPU voltage thus generated is sent from pin@º [VCPU] to pin1 [VDD] and pin$¶ [VDD] of
the system controller IC801 to start up IC801. The step-up circuit inside IC401 operates only when a Discman is in the STOP mode.
When a Discman is in a mode other than the STOP mode, the 2.75 V generator circuit, which is discussed later, starts operation and
outputs the switching waveform from pin@ª [VOUT2] of the POWER CONTROLLER IC401, so the input of pin2 [IN] of the 4 V
REGULATOR IC402 is kept to approx. 3.5 V or higher at all times by the step-up cir cuit consisting of the switching output from pin@ª
[VOUT2], Q403, T401, D406, and C418. The output of the step-up circuit changes in the range of approx. 3.5 V to 8 V depending on the
conditions of load and power supply . The output volta ge that is stepped up to 4 V or higher is input to the 4 V REGULATOR IC402 and
is stepped down to 4 V by the SERIES REGULATOR inside IC402. The output voltage in the range of 3.5 V to 4 V is sent to pin@™
[VDO] of the POWER CONTROL IC401 via D404 from pin3 [OUT] of IC402 which stops operation of the step-up circuit inside
IC401.
*2-2: PNM (Pulse Number Modulation) wave
In the PNM wave, the pulse width is kept constant b ut the number of pulses is changed, whereas in the PWM wa ve, the duty ratio of the
pulse is changed.
— 6 —
IC401 POWER CONTROL
DCIN
BATTERY
R448
C439
L406
+
C430
D404
SERIES REGULATOR
Q414
+
C408
+
C418
OUT
R411
Q402
IN
2
3
IC402
4[V] REGULATOR
D406
D407
L401
5
2
C434
T401
3
4
Q403
R419
+
C428
INM3
RF3
VIN
SW
VDO
VOUT2
36
35
30
VCPU GENERATOR
21
22
ERROR
AMP.
+
-
3[V]
REFERENCE
29
VOLTAGE
REGULATOR
20
VCPU
TO IC403
OSC
VOLTAGE
DETECTOR
SYSTEM CONTROLLER
SECTION
17
PCB
— 7 —
Fig. 2-2 VCPU voltage generation circuit block diagram
VDD
1
— 8 —
VDD
47
SYSTEM CONTROLLER
PCON
27
IC801
4
TP401
VCC
TO IC801
5pin VCCMNT
VIN
VOLTAGE
C423
1
T401
5
3
C424
R428
R427
3
2
4
2
Q405
+
L403
R439
RV401
C433
R441
+
C402
VCC VOLTAGE
2.75[V]
C403
R440
1
Q403
IC401 POWER CONTROL
from IC504
1pin VG
12[V]
VOUT2
29
AMP.
COMP.
SAW
+
-
-
12
6
VREF
C435
DTC3
from IC801
27pin PCON
PCB
17
SYSTEM
ERROR AMP.
CONTROLLER
SECTION
OSC
16
3
RF2
SYNC
C415
R415
from IC502
46pin 176K
176.4[kHz]
(4fs)
Fig. 2-3 VCC voltage generation circuit block diagram
+
-
REF
INP2
5
Approx.0.6[V]
4
INM2
— 9 —
— 10 —
3. Generation of VCC Voltage
Fig. 2-3 shows the VCC voltage generation circuit block diagram.
(1) Operation when the operating mode is switched from STOP mode (SLEEP state) to PLAY mode
When either the PLAY key of the Discman or the PLAY key or the FF k e y or the REW key of the remote control is pressed, the system
controller IC801 outputs the "L" signal from pin@¶ [PCON]. When "L" is output, the SYSTEM CONTROLLER section inside IC401
starts its internal operation. As the SYSTEM CONTR OLLER section star ts internal operation, the PWM wa veform that is generated by
the PWM comparator inside IC401, is output from pin@ª [VOUT2] of the PO WER CONTR OL IC401. As the PWM wav eform is output
from pin@ª [VOUT2] of IC401, Q403 and Q405 start the switching operation which starts up the STEP-UP/DO WN DC-DC CONVER TER
that generates 2.75 V. The switching output from Q405 is smoothed out by C403 and is divided by the voltage-divider resistors of R439,
RV401, and R440. The output voltage from the voltage-divider resistors is fed back to pin5 [INP2] of IC401. Based on this feedback
voltage, IC401 controls the duty ratio of the PWM waveform that is generated by the PWM comparator, in order to control the output
voltage. The switching output from Q405 is at the same time smoothed out by L403 and C402 to generate the VCC voltage (2.75 V ). As
the VCC voltage is generated, the DSP IC502 starts up so tha t the 4fs signal is sent to pin!§ [SYNC] of the PO WER CONTR OL IC401.
As the 4fs signal is input to IC401, the SYSTEM CONTROLLER section inside IC401 switches the operation clock to the input 4fs
signal from internal oscillation to execute its operation.
(2) Operation when the operating mode is switched from PLAY mode to STOP mode (SLEEP state)
When either the STOP key of the Discman or that of the remote control is pressed, the system controller IC801 outputs the "H" signal
from pin@¶ [PCON]. This "H" signal stops the PWM output from pin@ª [VOUT2] of the POWER CONTROL IC401 to output the "L"
signal. This "L" output turns off Q403 and Q405 and stops outputting the VCC v oltage. As the VCC voltage is stopped, the 4fs signal is
no longer input to pin!§ [SYNC] of the POWER CONTR OL IC401. When the SYSTEM CONTROLLER section inside IC401 detects
that the input to pin!¶ [PCB] goes "H", it stops its internal operation. Note that when the RESUME function is turned off, the system
controller IC801 moves the optical pickup to the innermost circumference, and sets the output from pin@¶ [PCON] to "H". When the
RESUME function is turned on, the optical pickup is not moved to the innermost circumference.
The waveform timing chart during generation of the VCC voltage is shown in Fig. 2-4.
1
Q403
GATE
0_
2
Q405
COLLECTOR
3
BASE
0_
Q405
0_
4
TP401
VCC
0_
Fig. 2-4 Waveform timing chart during generation of the VCC voltage
– 12[V]
– 5[V]
– 3[V]
– -7[V]
– 2.75[V]
— 11 —
4. Generation of VG voltage
Figure 2-5 shows the VG voltage generation circuit block diagram.
As the VCC voltage 2.75 V is generated as shown, the D/A CONVERTER IC301 starts up. As IC301 starts up, X301 starts oscillating.
Then, the 384fs (16.9 [MHz]) signal is supplied to pin&¢ [XIN] of IC502 as the master clock of the DSP IC502 from pin!£ [CKO] of
IC301. Next, when the DSP IC502 starts up, 4fs (176.4 [kHz]) signal is generated from the 384fs signal that is input to pin&¢ [XIN] using
the frequency-divider inside IC502. Then the 4fs (176.4 [kHz]) signal is output from pin$§ [176K] to pin!§ [SYNC] of the POWER
CONTROL IC401. IC401 then outputs the 4fs (176.4 [kHz]) signal (see Fig. 2-6) to the COIL/MO TOR DRIVE IC504. As the 4fs (176.4)
[kHz]) signal is input to the COIL/MOTOR DRIVE IC504, the CHARGE PUMP circuit inside IC504 starts functioning and the VG
voltage (approx. 12 V) is generated. Approx. 12 V is output from pin1 [VG] of IC504.
Even though the VG voltage is nominally approx. 12 V, it changes in practice depending on the VIN voltage. For information during
repair, the CHARGE PUMP circuit inside IC504 is judged to be operating correctly when a voltage appro ximately three times higher than
the input signal to pin#™ [VCG] of the COIL/MOTOR DRIVE IC504 is output from pin1 [VG] of IC504.
The clock timing during generation of the VG voltage is shown in Fig. 2-6.
– 2.2 V
1
IC401
16pin SYNC 0_
– -0.4 V
2
IC401
15pin CKOUT 0_
– 4 V
Fig. 2-6 Clock timing during generation of the VG voltage
— 12 —
IC504
COIL/MOTOR DRIVE
VCC VOLTAGE
2.75[V]
DVDD
AVDD
CHARGE
VLG
IC502 DSP
UNREG
1
(4fs)
SYNC
VIN
77
1/96
1
74
XIN
176K
46
5
2
16
30
PUMP
3
CLK
(4fs)
CKOUT
15
IC401 POWER CONTROL
1
VG VG
23
32
VCG
UNREG
VG VOLTAGE
12[V]
DVDD
AVDD
XVDD
(384fs)
CKO
13
1
10
17
IC301 D/A CONVERTER
XTL1
15
X301
16.8935[MHz]
XTL0
16
Fig. 2-5 VG voltage generation circuit block diagram
— 13 —
— 14 —
2-4. Charging Circuit
Figure 2-7 shows the charging circuit block diagram.
(1) Operation of the system controller IC801 during charging
When the DC plug is connected to the DC jack, the supplied voltage is supplied to the system controller pin%¶ [DCINMNT] of IC801 and
PIN#¢ [DCIN] of POWER CONTROL IC401 via D415. Each IC detects that AC adapter is connected. After the system controller IC801
starts up and recognizes that AC adapter is connected, the system controller IC801 detects the rechar geable battery by the input terminal
of pin^¡ [CHGMHT2] as described below. When the system controller IC801 recognizes that a voltage is input to pin^¡ [CHGMNT2],
an "H" signal is output from pin!¡ [CHGON]. POWER CONTROL IC401 starts the charging operation by this "H" signal.
= Rechargeable Battery Detection =
The system controller IC801 performs the battery detection by pin^¡ [CHGMNT2]. When the rechargeable battery is inserted (see Fig.
2-8(a)), a voltage is input to pin^¡ [CHGMNT2] because cathode of the supplied rechargeable battery is exposed. When an alkaline dry
cell battery (size AA) is inserted (see Fig.2-8(b)), voltage is not input to pin^¡ [CHGMNT2] because cathode of the battery is molded. In
the system controller IC801, if no voltage is input to pin^¡ [CHGMNT2] , an "L" signal is output from pin!¡ [CHGON] and the charging
operation stops. When batteries are inserted as shown in Fig. 2-8(c), voltage is input to pin^¡ [CHGMNT2] of the system controller
IC801. An "L" signal is output from pin!¡ [CHGON] because the system controller IC801 detects that the voltage rise time is fast
(Generally, primary cell has a characteristic that the voltage rise time is faster than secondary cell.) and identifies that the inserted battery
is not a rechargeable battery, and an "L" signal is output from pin!¡ [CHGON]. Hence, the charging operation stops.
Rechargeable battery detection terminal
(Voltage is output because the
minus side of the rechargeable
battery is not molded.)
TO IC801
61pin CHGMNT2
(a)When rechargeable battery is inserted
Fig. 2-8 How to detect the rechargeable battery
Rechargeable battery detection terminal
(Voltage is not output because
the minus side of the battery
is molded.)
TO IC801
61pin CHGMNT2
(b)When alkaline battery is inserted
Rechargeable battery detection terminal
( Voltage is output because the
minus side of the rechargeable
battery is not molded.)
TO IC801
(Detects that the inserted battery is not
rechargeable battery because the voltage
rise time is fast.)
(c)Example of inserting rechargeable battery
and alkaline battery
61pin CHGMNT2
— 15 —
(2) Operation of POWER CONTROL IC401 during charging
POWER CONTROL IC401 contains the CHARGE CONTROL section which starts charging when the charge conditions shown in
T able. 2-2 are satisfied. When IC401 starts char ging, IC401 outputs the "H" signal from pin #£ [CHGSW]. This "H" signal turns Q401
on. At the same time, IC401 outputs the "H" signal inside IC401 to turn on the N-channel MOS FET Q1. As Q401 is turned on, the
voltage that is obtained by I-V converting the current flowing through the recharging battery with external resistors R412 to R414, is
input to pin1 [RS] of IC401. IC401 keeps the current constant at all times through the rechargeable battery by comparing the input
voltage at pin1 [RS] with the internal reference voltage (0.35 V) with the ERROR AMP. IC401 has a built-in monitor circuit inside the
CHARGE CONTROL section which monitors the charging voltage. The monitoring voltage is output to the system controller IC801
from pin#¡ [CHGOUT].
Table. 2-2 Charge conditions
Input
Pin #¢[DCIN]
During charging
(3) Operation when stopping charging
During charging, the system controller IC801 detects a –∆ V (minus delta V potential) by monitoring the voltages that are input to pin%ª
[CHGMNT1] and pin^¡ [CHGMNT2]. When the system controller IC801 detects a –∆ V, it stops charging by setting pin!¡ [CHGON]
to "L". In addition to the –∆ V detection system, the system controller IC801 uses the timer system (timer of approx. four hours) at the
same time in order to stop charging.
p –∆ V charging system:
This system is most widely used for charging nickel-cadmium and nickel-hydrogen rechargeable batteries. To control charging, this
system uses the characteristic that the battery voltage reaches its peak at the charge-end, then decreases as the battery temperature rises
due to oxygen gas absorption reaction of the negative electrode. This system is called the –∆V system. Refer to chapter 5 APPENDIX:
TYPES AND APPLICATIONS OF SECONDAR Y BATTERIES FOR PORT ABLE EQUIPMENT (RECHARGEABLE BATTERIES).
H
Pin !¶[PCB]HPin !•[CHGON]
H
Output
Pin #£[CHGSW]
H
— 16 —
R419
C434
INM3
RF3
(Approx.0.35[V])
36
35
IC401 POWER CONTROL
DCIN
BATTERY
R448
L406
C430
R433
C408
Q414
+
D415
R411
Q402
Q401
D407
VIN
DCIN
RS
30
34
1
Q1
DCIN
DETECTOR
+
+
ERROR
AMP
CHARGE
CONTROL
SECTION
IC403
CHARGE MONITOR
+
-
R434
R542
R567
R412
R401
R413
R414
CHGSW
BATM
33
32
CHARGE
MONITOR
CIRCUIT
DCINMNT
CHGMNT2
57
61
IC801
59
11
27
CHGMNT1
CHGON
PCON
R823
("H":during charging)
("H":during charging)
CHGOUT
CHGON
PCB
31
18
17
CHARGE MONITOR
VOLTAGE
SYSTEM CONTROLLER
Fig. 2-7 Charging circuit block diagram
— 17 —
— 18 —
2-5. APC Circuit
Figure 2-9 shows the APC circuit block diagram.
(1) AC adapter drive operation
When the system controller IC801 detects that the PLA Y key is pressed, IC801 outputs the "L" signal from pin@¶ [PCON]. When "L" is
output, the POWER CONTROL IC401 starts its internal operation. As Q411 is turned off, the reference voltage (approx. 2 V) that is
obtained by dividing the VCPU voltage by the voltage-divider resistors of R437 and R438, is input to pin9 [INP1] of IC401. When the
POWER CONTROL IC401 starts its internal operation, the switching circuit inside IC401 starts and the APC (Automatic Power Contr ol)
circuit also starts so that the feedback voltage to pin8 [INM1] is maintained at 2 V at all times. During AC adapter drive operation, the
power voltage of 4.5 V is input to it, so only the step-down circuit consisting of the switching output from pin@§ [VOUT1] of IC401,
Q406, D410, L402, and C437, works. During AC adapter drive operation, the "L" signal is output from pin@¢ [UPCK1] of IC401 while
the "H" signal is output from pin@∞ [UPCK1B]. Thus the step-up circuit of the APC circuit does not operate (see Fig. 2-10 (1)).
(2) Battery drive operation
During battery drive operation, the APC circuit is controlled so that the feedback voltage to pin8 [INM1] of IC401 stays at 2 V at all
times in the same manner as in the AC adapter drive operation. However, the step-up circuit of the APC circuit works when the battery
voltage decreases. When the battery voltage decreases while the APC circuit is operating, the input voltage to pin8 [INM1] of IC401
decreases. As the input voltage to pin8 [INM1] of IC401 decreases, the output voltage from the ERROR AMP inside IC401 (i.e., output
of pin7 [RF1] of IC401) increases which decreases the input voltage to pin!¡ [DTC1]. Hence, the reference input voltage to
COMPARATOR 2 inside IC401 decreases so that a PWM waveform having a high duty ratio is output from COMPARATOR 2. The
PWM waveform thus generated is output from pin@¢ [UPCK1] and pin@∞ [UPCK1B] (see Fig. 2-10 (2)). Then Q407 and Q408 start
switching operation and the step-up circuit is activated. The APC circuit functions so that the feedback voltage to pin 8 [INM1] stays at
2 V at all times.
The Discman power supply has a built-in protection circuit that protects the laser diode from damage in case the power supply suffers a
momentary failure. When the power supply is momentarily shut down, Q417 is turned on and so the voltage that is obtained by dividing
the VCPU voltage by the voltage-divider resistors of R422 and R432, is sent to Q411 which turns on Q41 1. This decreases the re ference
voltage input to the APC circuit, i.e., pin9 [INP1] that protects the laser diode from damage.
Figure 2-10 shows the operation waveforms of the APC circuit during battery drive operation.
Describing the APC operation in more detail, the APC circuit operation maintains the PD value to 150 mV using a feedback loop inside
the RF AMP IC501. When the PD value is 150 mV, the input voltage to pin8 [INM1] of POWER CONTROL IC401 becomes approx.
2 V.
— 19 —
— 20 —
OPTICAL
PICK-UP BLOCK
(DAX-11D)
PD
LD
PD
7
IC501
RF AMP.
+
-
REF
VCPU
3[V]
R437
1M
C429
R430
R438
PCB
INP1
9
VCPU
R442
Q409
C416
R420
6
VCPU
3[V]
R417
R451
R444
Q410
R418
R443
C435
C438
R423
RF1
INM1
VREF
DTC3
DTC1
12
11
(2[V])
SYSTEM
CONTROLLER
7
ERROR
AMP.
+
8
6
-
VREF
STEP-DOWN SWITCHING CIRCUIT
SAW
STEP-UP SWITCHING CIRCUIT
SECTION
COMP.1
-
+
START-UP
+
-
COMP.1
IC401
POWER CONTROL
17
30
10
26
24
25
VIN
CMP1
VOUT1
UPCK1
UPCK1B
1
D410
2
3
Q406
L402
Q407
VIN
VOLTAGE
VIN
VOLTAGE
L404
+
C437
2.2M
Q408
+
C420
C432
L405
R404
0
Q411
Q417
R402
R432
R424
R422
from IC801
27pin PCON
VIN
VOLTAGE
VCPU
3[V]
— 21 —
TP411
IOP+
Fig. 2-9 APC circuit block diagram
— 22 —
IC602 D-RAM
DETECTOR
OPTICAL PICK-UP
BLOCK
DAX-11D
5,9-12,14-18
A0-A9
IC502
DSP
IC501
A0-A9
35-44
RF AMP.
C
25
B
26
27
28
RF AMP.
D
A
(A+B+C+D)
16
EFM
EFM
3
DSP
SECTION
68
70
69
LRCK
BCLK
DATA
LRCI
BCKI
DATI
12
13
11
I/F
D-RAM CONTROLLER
ADPCM
ENCODER
16bit→5bit
WFCK
37
TP510
7.35[kHz]:during ESP OFF
I/F
12.6[kHz]:during ESP ON
1-2,24-25
D0-D3
D0-D3
29-32
ADPCM
DECODER
5bit→16bit
I/F
IC601
D-RAM CONTROLLER
I/F
15
14
16
LRCO
BCKO
DATO
LRCK
BCK
DATA
IC301
D/A CONVERTER
24
23
D/A
CONV.
22
15
16
LO
9
RO
5
L-ch
R-ch
XTLI
X301
16.9[MHz]
XTLO
(384fs)
(NOTE:when servo operation
41
SQCK
42
CDATA
44
RW
74
XIN
is stable.)
26
SCLK
24
XLT
25
SDTI
21
SDTO
9
CLK
13
CKO
XLT
SCK
41 37
RW
26
CDATA
24
SQCK
25
Fig. 2-11 ESP (Electronic Shock Protection) circuit block diagram
SDTO
39
(384fs)
SDTI
40
IC801
SYSTEM CONTROLLER
— 23 —
— 24 —
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