JVC PC-X250 User manual

PC-X250
Contents
Safety precaution ------------------ 2 Block/Wiring Diagram ------------------ 25
Disassembly method -------------- 4 Circuit Diagram -------------------------- 27
Adjustment method ---------------- 6 PCB drawing ----------------------------- 29
TOC read ---------------------------- 10 Assembly ---------------------------------- 32
Major IC Description -------------- 11 Packing ------------------------------------ 42
No. 28001
Oct. 2001
COPYRIGHT © 2001 VICTOR COMPANY OF JAPAN,LTD (By JCA)
SERVICE MANUAL
CD PORTABLE COMPONENT SYSTEM
PC-X250
Area Suffix
J ---- USA
C ---- Canada
Unit No
SP-PCX250 Unit No
SP-PCX250
Unit No
CA-PCX250

PC-X250
1. This design of this product contains special hardware and many circuits and components specially for
safety purposes. For continued protection, no changes should be made ti the original design unless
authorised in writing by the manufacturer. Replacement parts must be identical to those used in the
original circuits. Services should be performed by qualified personel only.
2. Alterations of the design or circuitry of the product should not be made. Any design alterations of the
product should not be made. Any design alterations or additions will void the manufacturer's warranty
and will further relieve the manufacturer of responsibility for personal injury or property damage
resulting therefrom.
3. Many eletrical and mechanical parts in the products have special safety-related characteristics.
These characteristics are often not evident from visual inspection nor can the protection afforded by
them necessarily be obtain by using replaement components rated for higher voltage, the Parts
List of Service manual. Electrical components having such features ate identified by the shading on the
schematics and by ( ! ) on the parts List in the Service Manual. The use of a substitute
repalcement which does not have the same safety characteristics as the recommended replacement
parts shown in the Parts List of Service manual may create shock, fire, or other hazards.
4. The leads in the products are routed and dressed with ties, clamps, tubing's, barriers and the like to
be separated from live parts, high temperatures parts, moving parts and/or sharp edges for the
prevention of electric shcok and fire hazard. When service is required, the original leat routing and
dress should be observed, and it should be confirmed that they have been returned to normal, after
re-assembling.
5. Leakage current check (Electrical Shock hazard testing)
After re-assembling the product, always perform an isolation check on the exposed metap Parts of the
product (antenna terminals, knobs, metal cabinet, screw heads, headphone jack, control shafts, etc.)
to be sure the product is safe to operate without danger of electrical shock.
Do not use a line isloation transformer during this check.
Plug the AC line cord directly into the AC outlet. Using a "Leakage Current Tester", measure the
leakage current from each ecposed metal parts of the cabinet, particularly and exposed metal
part having a return path to the chassis, to a known good earth ground. Any leakage current must
not exceed 0.5mA AC (r.m.s.)
Alternate check method
Plug the AC line cord directly into the AC outlet. Use an AC voltmeter having, 1,000 ohms per
volt or more sensitvity in the following manner. Connect a 1,500 ohm 10W resistor paralleled by a
0.15uF AC-type capacitor between an exposed
metal part and a known good earth ground.
Measure the AC voltage across the resistor with
the AC voltmeter.
Move the resistor connection to each exposed
metal part, particularly and exposed metal part
having a return path to te chassis and
measure the AC voltage across the resistor. Now,
reverse the plug in the AC outlet and repeat
each measurement. Voltage measured Any must
not exceed 0.75 V AC (r.m.s.). This corresponds
to 0.5 mA AC (r.m.s.).
1. This equipment has been designed and manufactured to meet international safety standards.
2. It is the legal responsibility of the repairer to ensure that these safety standards are maintained.
3. repairs must be made in accordance with the relevant safety standards.
4. It is essential that safety critical components are replaced by approved parts.
5. It mains voltage selector is provided, check setting for local voltage.
CAUTION
Burrs formed during moulding may be left over on some parts of the chassis. Therefore,
pay attention to such burrs in the case of performing repair of this system.
Safety Precautions
Warning
1 - 2

PC-X250
Preventing static electricity
Electrostatic discharge (ESD), which occurs when static electricity stored in the body, fabric, etc. is discharged,
can destroy the laser diode in the traverse unit (optical pcikup). Take care to prevent this when performing repairs.
1.1. Grounding to prevent damage by static electricity
Static electricity in the work area can destroy the optical pickup (laser diode) in devicessuch as DVD players.
Be careful to use proper grounding in the area where repairs are being performed.
1.1.1. Gound the workbench
1.
Ground the workbench by laying conductive material (such as a conductive sheet) or an iron plate over
it before placing the traverse unit (optical pickup) on it.
1.1.2. Ground yourself
1.
Use an anti-static wrist starp to release and static electricity built up in your body.
1.1.3. Handling the optical pcikup
1.
In order to maintain quality during transport and before installation, both sides of the laser diode on the
replacement optical pickup are storted. After replacement, return the shorted parts to their original condition.
(Refer to the text.)
2.
Do not use a tester to check the condition of the laserdiode in the optical pickup. The tester's internal power
source can easily destory the laser diode.
1.2. Handling the traverse unit (optical pickup)
1.
Do not subject the traverse unit (optical pcikup) to strong shocks, as it is a sensitive, complex unit.
2.
Cut off the shorted part of the flexible cable using nippers, etc. after replacing the optical pickup. For specific
details, refer to the replacement procdeure in the text. Remove the anti-static pin when replacing the traverse
unit. Be careful not to take too long a time when attaching itto the connector.
3.
Handle the flexible cable carefully as it may break when subjected to strong force.
4.
It is not possible to adjust the semi-fixed resistor that adjusts the laser power. Do not return it.
1 - 3

PC-X250
Disassembly method
Removing the rear panel
1.
From behind the body, remove the Five screws
A
retaining the rear panel.
2.
Then remove the Two screws
B
retaining the bottom of rear panel.
3.
Take out the rear panel from the body.
Note:
Be careful of the FM antenna white wire, it is connection with the tuner PCB up side.
You can directly take out from the tuner PCB.
When you re-assembly the product, plug the FM antenna white wire into the Tuner PCB's
"FM ANT" position.
Screw A.
Screw A.
Screw B.
1 - 4

Removing the Audio Board
1.Open & remove the rear panel
2. Remove the Connector CN201, CN202, CN203, CN405, CN502, CN801
& CN301 on the Audio Board.
3. Remove the two Screws Cretaining the Audio Board.
CN202 Screw C
CN201
CN502
CN203
CN801 CN405
CN301
Screw D
Removing the CD Mechanism
1 Open & remove the rear panel
2 Remove the Audio PCB
3 Remove the Two Screws Dretaining the CD Tray Backet.
Removing the Tuner PCB Screw E
1 Open & remove the rear panel.
2 Remove the Audio PCB.
3 Remove CD mechanism.
4 Remove the Eight Screws Eretaining
on the Tuner Board.
PC-X250
1 - 5

Ad
j
ustment method
Measurement instruments required for Tuner section
adjustment
1Low frequency oscillator Voltage applied to tuner ---------- +B:DC 4.9V
This oscillator should have a capacity to output VT:DC 12V
0dBs to 600 at an oscillation frequency of Reference measurement ----- 26.1mV(0.28V)/3
50Hz-20KHz output
Input positions ----- AM : Standard loop antenna
2Electronic voltmeter FM : TP1 (hot) and TP2 (GND)
3Distortion meter
4Frequency counter Standard measurement position of volume
5Wow & flutter meter
6Test tape Bass ----------------------------------------------------- Off
TCC-112 : Tape speed and running unevenness (3KHz) Active hoper bass pro ------------------------ Off
TCC-140 : Reference level (1KHz) Up and down adjustment of volume ----- Vol : 23
TCC-182A : Head angle (8KHz) , playback frequency
characteristics (1KHz) and dubbing frequency Precautions for measurement
characteristics (125Hz and 8KHz) 1 Apply 30PF and 33 Kohm to the IF sweeper output
Because of frequency - mixed tape with 63 , 1 , 10 and side and 0.082UF and 100 Kohm in series to the
14KHz (250nWb/m -24dB) , use this tape together sweeper input side .
with a filter . 2 The IF sweeper output level should be made as
7Black tape low as possible within the adjustable range .
TYPE I : AC - 225 3 Since the IF sweeper is a fixed device , there is no
TYPE II : AC - 514 need to adjust this sweeper .
8Torque gauge : For play and back tension 4 Since a ceramic oscillator is used , there is no need
FWD(TW2111A) , REV(TW2121a) and FF/REW(TW2231A) to perform any MIX adjustment .
5 Since a fixed coil is used , there is no need to
Measurement conditions adjust the FM tracking .
6 The input and output earth systems are separated .
Power supply voltage ---------------- AC 120V (60Hz) In case of simultaneously measuring the voltage in
Reference output -------------- Speaker : 0.866V/3 both of the input and output systems with an
Headphone : 0.245V/32 electronic voltmeter for two channels , therefore , the
Reference frequency and ----- 1KHz , AUX : 450~500mV earth should be connected particularly carefully .
input level 7 In the case of BTL connection amp. , the minus
Input for confirming recording and ------- AUX : -28dBs terminal of speaker is not for earthing . Therefore , be
playback characteristics sure not to connect any other earth terminal to this
Measurement output terminal ---------- Speaker J3002 terminal . This system is of an BTL system .
* Load resistance --------------------------- 3 8 For connecting a dummy resistor when measuring
the output , use the wire with a greater code size .
Radio Input signal 9 Whenever any mixed tape is used , use the band
pass filter (DV-12V)
AM frequency -------------------------------- 400Hz
AM modulation ---------------------------------- 30%
FM frequency --------------------------------- 1 KHz
FM frequency deviation ------------------------ 22.5KHz
PC-X250
1 - 6

TAPE DECK ADJUSTMENTS
1 HEAD AZIMUTH ADJUSTMET
( 1 ) Load the test tape TCC-182A 8KHz for azimuth
adjustment.
( 2 ) Press the PLAY button.
( 3 ) Use a cross-tip screwdriver to turn the screw for azimuth
adjustment so that the left and right output are maximized
( 4 ) Press the STOP button
( 5 ) After completion of the adjustment. Use thread lock(TB-1401B)
to secure the azimuth-adjustment screw.
2 AC BIAS FREQUENCY ADJUSTMENTS
( 1 ) Connect frequency counter to CN202(BS);
( 2 ) R/P swith in recording state;
( 3 ) Adjusting T801 use a plastic screwdriver, AC bias frepuency ;61kHz +/- 1kHz..
3 TAPE SPEED ADJUSTMENT
( 1 ) Insert the test tape(MTT-111N,3,000 HZ)
( 2 ) Press the PLAY button.
( 3 ) Use a flat-tip screwdriver to turn the VR 501.
Adjust VR501 so that the frequency counter
become 3,000Hz
TAPE HEAD AND SPEED ADJUSTMENT DIAGRAM
CASS DECK
A DECK B DECK
A
P HEAD
L. SW
A
L. SW
E HEAD
P/R HEAD
PC-X250
1 - 7

Tape recorder section
Measurement Standard Adjusting]
conditions Values positions
Confirmation Test tape 1 Playback the test tape TCC-182A (8KHz) Maximum Adjust the head
of head angle :TA-182A(8KHz) 2 With the recording & playback mechanism, output azimuth screw
Measurement output adjust the head azimuth screw so that the only when the
terminal left and right output levers become head has been
:Speaker terminal maximum, After adjustment, lock the head changed
Sperker R azimuth at least by half turn.
(Load resistance:3 )
:Headphone terminal
Confirmation Test tape Adjust VR501 so that the frequrncy counter Tape speed VR501
of tape speed :TCC-112(3000Hz) reading becomes 3,010Hz +/-15Hz when of deck
playing back the test tape TCC-112 (3000Hz) with :3,010Hz
Measurement output playback and recording mechanism after +/-15Hz
terninal ending forward winding if the taoe.
:Headphone terminal
Reference Values for Confirmation Items
Measurement Standard Adjusting]
conditions Values positions
Wow & flutter Test tape When the test tape TCC-112 (3000Hz) has been 0.25% or
:TCC-112(3000Hz) played back with the recording and playback less
mecganism at the beginning of forward (WRMS)
Measurement outut winding, the frequency counter reading of
terminal wow & flutter should be 0.25% or less
:Headphone terminal (WRMS).
Items Measrrnment methed
ITEMS Measrrnment methed
PC-X250
1 - 8

Electrical Performance
Measurement Standard Adjusting
conditions Values positions
Adjustment of Mode:Forward or 1 With the recording and playback
recording bias reverse mode mechanism, load thd test tapes
current Recording mode TDK-60 , and set the mechanism to the recording 4.5 A
(Reference Test tape and pausing condition in advance . +/-0.5 A
Value) TDK-60
Measurement output 2 After connecting 100 in series to the
termial recorder head, measure the bias current
:Both recording and with a valve voltmeter at both of the
headphone terminals terminals
Adjustment of Reference frequency 1 with the recording and playback Output
recording and :1KHz and 8KHz mechanism, load the test tapes (TDK-60) deviation
playback (REF.:-20dB) and set the mechanism to the between
frequency Test tape recording and pausing condition in 1KHz and
characteristics TDK-60 advance 8KHz
Measurement input 2 While repetitively inputting the reference :-1dB +/-2dB
terminal frequency signal of 1KHz and 10KHz from
:OSC IN OSC IN, record and playback the tape.
Reference Values for Electrical Function Confirmation Items
Measurement Standard Adjusting
conditions Values positions
Recording Forward or reverse 1 While changing over to and form BIAS 1 61KHz
bias Test tape and 2, confirm that the frequency is +/-1KHz
frequency TDK-60 changed
Measurement 2 With the recording and playback
terminal : BIAS TP on mechanism, load the test tape.
P.C. board (TDK-60 ) , and set the
mechanism to the recording and pausing
condition in advance.
3 Confirm that the BIAS TP frequency on the
P.C. board is 61KHz +/-1KHz
ITEMS Measrrnment methed
Items Measrrnment methed
PC-X250
1 - 9

Flow of functional operation until TOC read
Check Point
Check that the voltage at the pin
16 of IC903 is OV (a moument)?
Check that the voltage at the
pin64 of IC901 + side is + 5V?
Confirm that the Focus error
s-cuve signal at the pin16 of
IC901 is approx.2V p-p
Tracking error waveform at TOC reading Confirm that the signal from
pin27 IC901 is 0V as a
accelerated pulse during
approx.400ms
Confirm the waveform of
the Tracking error signal
at the pin15 of IC901 (R975)
(See fig-1)
Confirm the eys-pattern
at the lead of TP1
Power ON Power Key Slider turns REST
SW ON.
Automatic tuning
of TE offset
Laser ON
Detection of disc
Automatic tuning of
Focus offset
Automatic measurement of
Focus A-curve amplitude
Disc is rotated
Focus servo ON
(Tracking servo ON)
Automatic measurement of
Tracking error amplitude
Automatic tuning of
Tracking error balance
Automatic tuning of
Focus error balance
Automatic tuning of
Focus error gain
Automatic tuning of
Tracking error gain
TOC reading
Play a disc
Approx 3sec
pin 15 of
IC901(TO)
Tracking
servo
off status
Tracking
servo
on status
Disc to be
braked to
stop
TOC reading
finishes
Disc status
to rotate
Automatic measurement
of TO amplitude and
automatic tuning of
TO balance
500mV/div, 2mS/div Fig.1
VREF
Approx
1.8V
PC-X250
1 - 10

RAM: Data memory
ROM: Program memory
DP: Data pointer register
BNK: Bank register
APG: RAM page flags
AC: Accumulator
ALU: Arithmetic and logic unit
B: B register
OPG: ROM page flag
PC: Program counter
IR: Instruction register
STS1: Status register 1
STS2: Status register 2
STS3: Status register 3
STS4: Status register 4
STS5: Status register 5
PLA: Segment data and strobe programmable logic
array
WAIT.C:Waiting time counter
Description of major ICs
LC587008
PC-X250
1 - 11
System Block Diagram for the LC587008, LC587006 and LC587004

LC72131 Block Diagram
PC-X250
1 - 12

LC72131 Pin Functions
Pin No.
Symbol (MFP pin Nos. are Type Functions Circuit configuration
in parentheses.)
XIN
XOUT
FMIN
AMIN
CE
CL
DI
DO
VDD
1 (1)
22 (20)
16 (14)
15 (13)
3 (2)
5 (4)
4 (3)
6 (5)
17 (15)
Xtal OSC
Local oscillator
signal input
Local oscillator
signal input
Chip enable
Clock
Data input
Data output
Power supply
¥ Crystal resonator connection
(4.5/7.2 MHz)
¥ FMIN is selected when the serial data input DVS bit is
set to 1.
¥ The input frequency range is from 10 to 160 MHz.
¥ The input signal passes through the internal divide-by-
two prescaler and is input to the swallow counter.
¥ The divisor can be in the range 272 to 65535. However,
since the signal has passed through the divide-by-two
prescaler, the actual divisor is twice the set value.
¥ AMIN is selected when the serial data input DVS bit is
set to 0.
¥ When the serial data input SNS bit is set to 1:
Ñ The input frequency range is 2 to 40 MHz.
Ñ The signal is directly input to the swallow counter.
Ñ The divisor can be in the range 272 to 65535, and
the divisor used will be the value set.
¥ When the serial data input SNS bit is set to 0:
Ñ The input frequency range is 0.5 to 10 MHz.
Ñ The signal is directly input to a 12-bit programmable
divider.
Ñ The divisor can be in the range 4 to 4095, and the
divisor used will be the value set.
Set this pin high when inputting (DI) or outputting (DO)
serial data.
¥ Used as the synchronization clock when inputting (DI) or
outputting (DO) serial data.
¥ Inputs serial data transferred from the controller to the
LC72131.
¥ Outputs serial data transferred from the LC72131 to the
controller.
The content of the output data is determined by the
serial data DOC0 to DOC2.
¥ The LC72131 power supply pin (VDD = 4.5 to 5.5 V)
¥ The power on reset circuit operates when power is first
applied.
PC-X250
1 - 13

LC72131 Pin Functions
Pin No.
Symbol (MFP pin Nos. are Type Functions Circuit configuration
in parentheses.)
VSS
BO1
BO2
BO3
BO4
IO1
IO2
PD
AIN
AOUT
IFIN
21 (19)
7 (6)
8 (7)
9 (8)
10 (9)
11 (10)
13 (12)
18 (16)
19 (17)
20 (18)
12 (11)
Ground
Output port
I/O port
Charge pump
output
LPF amplifier
transistor
IF counter
¥ The LC72131 ground Ñ
¥ Dedicated output pins
¥ The output states are determined by BO1 to BO4 bits in
the serial data.
Data: 0 = open, 1 = low
¥ A time base signal (8 Hz) can be output from the BO1
pin. (When the serial data TBC bit is set to 1.)
¥ Care is required when using the BO1 pin, since it has a
higher on impedance that the other output ports (pins
BO2 to BO4).
¥ All output ports are set to the open state following a
power on reset.
¥ I/O dual-use pins
¥ The direction (input or output) is determined by bits IOC1
and IOC2 in the serial data.
Data: 0 = input port, 1 = output port
¥ When specified for use as input ports:
The state of the input pin is transmitted to the controller
over the DO pin.
Input state: low = 0 data value
high = 1 data value
¥ When specified for use as output ports:
The output states are determined by the IO1 and IO2
bits in the serial data.
Data: 0 = open, 1 = low
¥ These pins function as input pins following a power on
reset.
¥ PLL charge pump output
When the frequency generated by dividing the local
oscillator frequency by N is higher than the reference
frequency, a high level is output from the PD pin.
Similarly, when that frequency is lower, a low level is
output. The PD pin goes to the high impedance state
when the frequencies match.
¥ The n-channel MOS transistor used for the PLL active
low-pass filter.
¥ Accepts an input in the frequency range 0.4 to 12 MHz.
¥ The input signal is directly transmitted to the IF counter.
¥ The result is output starting the MSB of the IF counter
using the DO pin.
¥ Four measurement periods are supported: 4, 8, 32, and
64 ms.
1 - 14
PC-X250

Pin No. Pin Description Notes
¥ Connection to the 0.5 ´VDD voltage generator circuit used as the
analog signal ground.
Applications must connect a capacitor of about 10 µF between this pin
and VSS to exclude power supply ripple.
28 Vref
¥ Chip enable
Data is written to the internal latch when this pin goes from high to low.
The internal analog switches operate at this point. Data transfer is
enabled when this pin is high.
2CE
¥ Serial data and clock inputs used for IC control.
1
30
DI
CL
¥ Ground3 VSS
¥ Power supply29 VDD
LC75342 Pin Functions.
¥ Electronic volume and tone control testing
This pin must be tied to VSS during normal operation.
4VSS
¥ Unused.
These pins must be left open or connected to VSS during normal
operation.
15
16
27
NC
PC-X250
1 - 15
DI 1 30 CL
CE 2 29 VDD
VSS 3 28 VREF
TEST 4 27 NC
LOUT 5 26 ROUT
LBASS2 6 25 RBASS2
LBASS1 7 24 RBASS1
LTRE 8 23 RTRE
LIN 9 22 RIN
LSELO 10 21 RSELO
L4 11 20 R4
L3 12 19 R3
L2 13 18 R2
L1 14 17 R1
NC 15 16 NC
TOP VIEW
LC75342
LC75342 Pin Assignment

1 - 16
PC-X250
LC75342 Pin Functions
Pin No. Pin Description Notes
¥ Input signal connections
14
13
12
11
17
18
19
20
L1
L2
L3
L4
R1
R2
R3
R4
¥Connections for the resistors and capacitors that form the bass band
filters.
7
6
24
25
LBASS1
LBASS2
RBASS1
RBASS2
¥ Input selector outputs
10
21
LSEL0
RSEL0
¥ Volume and equalizer outputs
5
26
LOUT
ROUT
8
23
LTRE
RTRE ¥ Connections for the capacitors that form the treble band filters.
9
22
LIN
RIN ¥ Volume control and equalizer input

LC78622 Pin Function
Note: The same potential must be supplied to all power supply pins, i.e., VDD, VVDD, LVDD, RVDD, and XVDD.
Pin No. Symbol I/O Function
51 SBCK I Subcode readout clock input. This is a Schmitt input. (Must be connected to 0 V when unused.)
52 FSX O Output for the 7.35 kHz synchronization signal divided from the crystal oscillator
53 WRQ O Subcode Q output standby output
54 RWC I Read/write control input. This is a Schmitt input.
55 SQOUT O Subcode Q output
56 COIN I Command input from the control microprocessor
57 CQCK I Input for both the command input clock and the subcode readout clock. This is a Schmitt input.
58 RES I Chip reset input. This pin must be set low briefly after power is first applied.
59 TST11 O Test output. Leave open. (Normally outputs a low level.)
60 16M O 16.9344 MHz output.
61 4.2M O 4.2336 MHz output
62 TEST5 I Test input. A pull-down resistor is built in. Must be connected to 0 V.
63 CS I Chip select input. A pull-down resistor is built in. Must be connected to 0 V if not controlled.
64 TEST1 I Test input. No pull-down resistor. Must be connected to 0 V.
LC78622 Pin Assignment
PC-X250
1 - 17

Pin No. Symbol I/O Function
1 DEFI I Defect detection signal (DEF) input. (Must be connected to 0 V when unused.)
2 TAI I Test input. A pull-down resistor is built in. Must be connected to 0 V.
3 PDO O External VCO control phase comparator output
4 VVSS ÐPLL pins Internal VCO ground. Must be connected to 0 V.
5 ISET AI PDO output current adjustment resistor connection
6 VVDD ÐInternal VCO power supply
7 FR AI VCO frequency range adjustment
8 VSS Ð Digital system ground. Must be connected to 0 V.
9 EFMO O Slice level control EFM signal output
10 EFMIN I EFM signal input
11 TEST2 I Test input. A pull-down resistor is built in. Must be connected to 0 V.
12 CLV+ODisc motor control output.
13 CLVÐO Three-value output is also possible when specified by microprocessor command.
14 V/P O Rough servo/phase control automatic switching monitor output. Outputs a high level during rough servo and a low level
during phase control.
15 HFL I Track detection signal input. This is a Schmitt input.
16 TES I Tracking error signal input. This is a Schmitt input.
17 TOFF O Tracking off output
18 TGL O Tracking gain switching output. Increase the gain when low.
19 JP+OTrack jump output.
20 JPÐO Three-value output is also possible when specified by microprocessor command.
21 PCK O EFM data playback clock monitor. Outputs 4.3218 MHz when the phase is locked.
22 FSEQ O Synchronization signal detection output. Outputs a high level when the synchronization signal detected from the EFM
signal and the internally generated synchronization signal agree.
23 VDD ÐDigital system power supply.
24 CONT1 I/O General-purpose I/O pin 1
25 CONT2 I/O General-purpose I/O pin 2 Controlled by serial data commands from the microprocessor. Any of these that are unused
26 CONT3 I/O General-purpose I/O pin 3 must be either set up as input ports and connected to 0 V, or set up as output ports and
27 CONT4 I/O General-purpose I/O pin 4 left open.
28 CONT5 I/O General-purpose I/O pin 5
29 EMPH O De-emphasis monitor pin. A high level indicates playback of a de-emphasis disk.
30 C2F O C2 flag output
31 DOUT O Digital output. (EIAJ format)
32 TEST3 I Test input. A pull-down resistor is built in. Must be connected to 0 V.
33 TEST4 I Test input. A pull-down resistor is built in. Must be connected to 0 V.
34 N.C. Ð Unused. Must be left open.
35 MUTEL O Left channel mute output
36 LVDD ÐLeft channel Left channel power supply
37 LCHO O one-bit D/A converter Left channel output
38 LVSS Ð Left channel ground. Must be connected to 0 V.
39 RVSS Ð Right channel ground. Must be connected to 0 V.
40 RCHO O Right channel Right channel output
41 RVDD Ðone-bit D/A converter Right channel power supply
42 MUTER O Right channel mute output
43 XVDD ÐCrystal oscillator power supply.
44 XOUT OConnections for a 16.9344 crystal oscillator element
45 XIN I
46 XVSS Ð Crystal oscillator ground. Must be connected to 0 V.
47 SBSY O Subcode block synchronization signal output
48 EFLG O C1, C2, single and double error correction monitor pin
49 PW O Subcode P, Q, R, S, T, U, V and W output
50 SFSY O Subcode frame synchronization signal output. This signal falls when the subcodes are in the standby state.
LC78622 Pin Functions
PC-X250
1 - 18

1
2
4
3
LA6541D Pin Assignment
PC-X250
1 - 19
Level Shift Level Shift
Level Shift Level Shift
Regulator

Pin No. Pin Name Description (Function)
1V
CC Power supply (shorted with pin 30)
2 Mute ON/OFF control for all BTL AMP outputs
3V
IN1 BTL AMP 1 input
4 VG1 BTL AMP 1 input (for gain control)
5V
O
1 BTL AMP 1 output (non-inverting side)
6V
O
2 BTL AMP 1 output (inverting side)
7 GND GND (minimum electric potential)
8 GND GND (minimum electric potential)
9 GND GND (minimum electric potential)
10 VO3 BTL AMP 2 output (inverting side)
11 VO4 BTL AMP 2 output (non-inverting side)
12 VG2 BTL AMP 2 input (for gain control)
13 VIN2 BTL AMP 2 input
14 REG OUT Connection for collector of external transistor (PNP); 5 V supply output
15 REG IN Connection for base of external transistor (PNP)
16 RES Reset output
17 CDReset output delay time setting (with capacitor)
18 VIN3 BTL AMP 3 input
19 VG3 BTL AMP 3 input (for gain control)
20 VO5 BTL AMP 3 output (non-inverting side)
21 VO6 BTL AMP 3 output (inverting side)
22 GND GND (minimum electric potential)
23 GND GND (minimum electric potential)
24 GND GND (minimum electric potential)
25 VO7 BTL AMP 4 output (inverting side)
26 VO8 BTL AMP 4 output (non-inverting side)
27 VG4 BTL AMP 4 input (for gain control)
28 VIN4 BTL AMP 4 input
29 VREF Reference voltage input for level shift circuit
30 VCC Power supply (shorted with pin 1)
LA6541D Pin Functions
PC-X250
1 - 20