NEC PF-68T32 Schematic
Nov. 2003
NEC Corporation
Service manual
68 Cm STEREO Color Television
MODEL : DTE-29U1TH
PF-68T32
CHASSIS : CP-785F
S/M No. : TCP785FEF0
Contents
1 - Main features 2
1-1 Specifications
2
1-2 External Terminals 2
1-3 Channel table 4
2 - Safety instruction
7
3 - Alignment instructions
8
3-1 Microcontroller configuration : Service mode
8
3-2 Microcnotroller configuration : Option
8
3-3 TV set Alignment
10
4 - IC description
12
4-1 TDA936x TV signal processor - TXT with embedded
-Controller 12
4-2 MSP341x Multistandard Sound Processor
19
4-3 TDA894x J Stereo Audio Amplifier
23
4-4 TDA835x J Vertical Amplifier
24
4-5 TDA6107JF
26
4-6 24C08 8 K bit EEPROM
27
4-7 STR-F665X
28
5 - Circuit description
30
5-1 Block diagram
30
5-2 IF
34
5-3 Source switching
35
5-4
-Controller I/O pin configuration and function 35
5-5 Sound processing
36
5-6 Sound amplification
37
5-7 Vertical deflection
38
5-8 Power supply (STR-F665X)
39
5-9 TV start-up, TV normal run and stand by mode operations
43
6 - Service parts list
50
6-1 Part List
50
6-2 All Electrical Parts List
51
6-3 Control Assembly Parts Lists
64
6-4 Compaitible Components List
65
7 - Exploded view
66
8 - PCB Layout
67
8-1 Main PCB
67
8-2 AV PCB
68
9 - Circuit Diagram
69
-1--1-
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Service Manual CP-785F
1-1 Specifications
1 - Main Features
1-2 External Teminals
1-2-1 Input 1 : (The Rear Side) RCA
TV standard PAL, - B/G, H, NTSC(AV Only)
Sound system NICAM B/G
FM 2Carrier B/G
Power consumption 116W approx.
Sound Output Power 5W x 5W (at 60% mod, 10% THD)
Speaker 7W 8 ohm x 2
Teletext system 10 pages memory FASTEXT (FLOF or TOP) : Option
Aerial input 75 ohm unbalanced
Channel coverage Off-air channels, S-cable channels and hyperband
Tuning system frequency synthesiser tuning system
Visual screen size 68 Cm
Channel indicatio On Screen Display
Program Selection 100 programmes
Aux. terminal INPUT1(RCA) : Audio / Video In.
INPUT2(RCA) : Audio / Video In
OUTPUT(RCA) : MONITOR OUT
DVD:Y/Cr/Cb/Audio in
Headphone jack (3.5 mm) on the right front of cabinet
Remote Control Unit R-44N08(RD-D90) for with Teletext
Pin Signal Matching value
1(Yellow) Video Input 1.0 Vpp+/- 3dB, Impedance 75 ohm
2(White) Audio Input Left 0.5 Vrms, Impedance > 10k ohm
3(Red) Audio Input Right 0.5 Vrms, Impedance > 10k ohm
1-2-2 Input2 : (The right Side) RCA
Pin Signal Matching value
1(Yellow) Video Input 1.0 Vpp+/- 3dB, Impedance 75 ohm
2(White) Audio Input Left 0.5 Vrms, Impedance > 10k ohm
3(Red) Audio Input Right 0.5 Vrms, Impedance > 10k ohm
-2-
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Service Manual CP-785F
1-2-3 MONITOR OUTPUT & DVD INPUT(THE REAR SIDE)
Pin Signal Matching value
2 DVD Cb-in 0.7Vpp +/- 3dB, Impedence 75ohm
3 DVD Cr-in 0.7Vpp +/- 3dB, Impedence 75ohm
4 DVD Y-in 1Vpp +/- 3dB, Impedence 75ohm
5 DVD Audio Left 0.5 Vrms, Impedance > 10 kohm
6 DVD Audio Right 0.5 Vrms, Impedance > 10 kohm
7 Monitor Video-out 1Vpp +/- 3dB, Impedence 75ohm
8 Monitor Audio Left-out 0.5Vrms at RF sound FM 54% Mod(27Khz dev)
9 Monitor Audio Right-out 0.5Vrms at RF sound FM 54% Mod(27Khz dev)
74
VIDEO
A
U
D
I
O
L
(MONO)
R
DVD-Y
85
9
6
OUT DVD IN
2
Cb
3
Cr
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Service Manual CP-785F
1-3 Channel table
FREQUENCY TABLE CP-785F
CH AUSTRALIA N/Z land
C00 46.25
C01 57.25
C02 64.25
C03 86.25
C04 95.25
C05 102.25
C5A 138.25
C06 175.25
C07 182.25
C08 189.25
C09 196.25
C10 209.25
C11 216.75
N01 - 45.25
N02 - 55.25
N03 - 62.25
N08 - 203.25
N09 - 210.25
N10 - 217.25
-- C21 471.25
C22 479.25
C23 487.25
C24 495.25
C25 503.25
C26 511.25
C27 519.25
C28 527.25
C29 534.25
C30 541.25
C31 548.25
C32 555.25
C33 562.25
C34 569.25
C35 576.25
C36 583.25
C37 590.25
C38 597.25
C39 603.25
C40 610.25
C41 617.25
C42 624.25
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Service Manual CP-785F
CH AUSTRALIA N/Z land
C43 631.25
C44 638.25
C45 645.25
C46 652.25
C47 659.25
C48 666.25
C49 673.25
C50 680.25
C51 687.25
C52 694.25
C53 701.25
C54 708.25
C55 715.25
C56 722.25
C57 729.25
C58 736.25
C59 743.25
C60 750.25
C61 757.25
C62 764.25
C63 771.25
C64 779.25
C65 786.25
C66 793.25
C67 800.25
C68 807.25
C69 814.25
C70 C71 C72 C73 C74 C75 C76 C77 S01 105.25
S02 112.25
S03 119.25
S04 126.25
S05 133.25
S06 140.25
S07 147.25
S08 154.25
S09 161.25
S10 168.25
S11 231.25
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Service Manual CP-785F
CH AUSTRALIA N/Z land
S12 238.25
S13 245.25
S14 252.25
S15 259.25
S16 266.25
S17 273.25
S18 280.25
S19 287.25
S20 294.25
S21 303.25
S22 311.25
S23 319.25
S24 327.25
S25 335.25
S26 343.25
S27 351.25
S28 359.25
S29 367.25
S30 375.25
S31 383.25
S32 391.25
S33 399.25
S34 407.25
S35 415.25
S36 423.25
S37 431.25
S38 439.25
S39 447.25
S40 455.25
S41 463.25
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Service Manual CP-785F
2 - Safety instruction
WARNING: Only competent service personnel may carry out work involving the testing or repair
of this equipment.
X-RAY RADIATION PRECAUTION
1. Excessive high voltage can produce potentially hazardous X-RAY RADIATION. To avoid
such hazards, the high voltage must not exceed the specified limit. The nominal value of the
high voltage of this receiver is 28~30 KV at max beam current. The high voltage must not
under any circumstances, exceed 32 KV. Each time a receiver requires servicing, the high
voltage should be checked. It is important to use an accurate and reliable high voltage meter.
2.The only source of X-ray Radiation in this TV receiver is the picture tube. For continued X-ray
RADIATION protection, the replacement tube must be exactly the same type tube as
specified in the parts list.
SAFETY PRECAUTION
1. Potentials of high voltage are present when this receiver is operating. Operation of the
receiver outside the cabinet or with the back board removed involves a shock hazard from the
receiver.
1) Servicing should not be attempted by anyone who is not thoroughly familiar with the
precautions necessary when working on high voltage equipment.
2) Discharge the high potential of the picture tube before handling the tube. The picture tube is
highly evacuated and if broken, glass fragments will be violently expelled.
2. If any Fuse in this TV receiver is blown, replace it with the FUSE specified in the
Replacement Parts List.
3. When replacing a high wattage resistor (oxide metal film resistor) in circuit board, keep the
resistor 10 mm away from circuit board.
4. Keep wires away from high voltage or high temperature components.
5. This receiver must operate under AC 240 volts, 5O Hz. NEVER connect to DC supply or any
other power or frequency.
PRODUCT SAFETY NOTICE
Many electrical and mechanical parts in this equipment have special safety-related
characteristics. These characteristics are often passed unnoticed by a visual inspection and the
X-ray Radiation protection afforded by them cannot necessarily be obtained by using
replacement components rated for higher voltage, wattage, etc. Replacement parts which have
these special safety characteristics are identified in this manual and its supplements, electrical
components having such features are identified by designated symbol on the parts list. Before
replacing any of these components, read the parts list in this manual carefully. The use of
substitutes replacement parts which do not have the same safety characteristics as specified in
the parts list may create X-ray Radiation.
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Service Manual CP-785F
3 - Alignment instructions
3-1 Microcontroller configuration : Service mode
To switch the TV set into service mode please see instruction below.
1 - Select pr. number 91
2 - Adjust sharpness to minimum value and exit all menu.
3 - Quickly press the key sequence : RED - GREEN - menu
To exit SERVICE menu press menu key or Operate(Std By) key.
In Service Mode press OK to stop the microcontroller i.e. the I2C bus is free and the set can be
controlled by external equipment. Press OK again to allow the microcontroller to control the set again.
Section ITEMS
BARE DTE-29U1TH
REMARK
DATA (PF-68T32)
For AGC 32 23 Variable
Adjustment BIAS R/G 31/31 31/31 Variable/Variable
(Variable) DRIVE R/G/B 32/32/32 32/32/32 Variable/Variable/FIX
H-PARALLEL 31 26 FIX
H-BOW 42 34 FIX
H-SHIFT 25 33 Variable
V-SLOPE 32 31 Variable
V-Amplitude 39 20 Variable
V. S-Correction 13 29 FIX
V SHIFT 32 30 Variable
H-WIDTH 32 42 Variable
EW Parabola 32 23 Variable
Up-Conner 32 32 Variable
Dn-Conner 32 32 Variable
EW Trapezium 32 29 Variable
For Option 04 04 FIX (Tuner option Code)
Function (HOTEL)CH LOCK OFF Off
Change (HOTEL) Max Vol 15 43
(OPTION) Clock Pr. 01 07
SVHS ON 0FF
AV START OFF OFF
KEY LOCK OFF OFF
SCREEN 24 30
DVD IN OFF ON
AUTO OFF OFF ON
3-2 Microcontroller configuration : Option
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Service Manual CP-785A
Option Function
* Note : These Function is changed only Service Mode not Factory mode. So you must use the user s remote controller
- Change the PR. No. to 91 ==> change the sharpness to 00(min) in Picture control Menu ==> Exit the User control Menu ==> Press the
[RED],[GREEN],[MENU] quickly
- Then the Service Menu is appeared.
FUNCTION Description Remark
Option - This is the tuner option code. 0,1,2,3 :For D/W Remote controller
4,5,6,7 :For NEC Remote controller
CH LOCK ON/OFF - Channel Setting : Impossible/possible
- When this function is active, It is impossible to change
the channel data(can not enter the INSTALL menu)
Max Vol 00~43(max) - this is the limited Volume function.
- it is variable to 43(max) from 00(min).
Clock Pr. - it change the reference channel for Automatic clock setting.
SVHS ON/OFF - When SVHS is active, The AV mode is changed to SVHS mode. CP-785F can t operate the S-VHS.
It operate to the CP-785A(DTE-29/25G5TH)
AV START ON/OFF - When AV start is active, the set always start in av1 mode
(main AC switch on/off & remote controller on/off)
- In case if virgin EEPROM, the default setting is OFF.
KEY LOCK ON/OFF - When active the local keyboard can t be used.
- In case if virgin EEPROM, the default setting is OFF.
SCREEN - It is adjust screen point.
- It requires for screen adjustment at the manufacture.
DVD IN ON/OFF - When DVD IN is active, The AV mode is changed to DVD mode.
AUTO OFF ON/OFF - When AUTO OFF is active, If broadcasting signal is not present.
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Service Manual CP-785F
3-3 TV set Alignment
3-3-1 - G2 alignment
- TV in AV mode without video signal Black screen.
- TV preset with WP Red, WP Green and WP Blue equal to 32.
- TV preset with Black R, Black G equal to 32.
- Set TV in NORMAL I mode
- Adjust screen volume ( on FBT ) such that the highest cathod cut-off voltage measured on CRT
board, is V cut off
5V.
Screen size Vcut-off
25 140V
29 140V
3-3-2 - White balance
- Select a dark picture and adjust Black G and Black R to the desired colour temperature.
- Select a bright picture and adjust WP Red, WP Green, WP Blue to the desired colour
temperature.
3-3-3 - Focus
- Adjust the Focus volume ( on FBT ) to have the best resolution on screen.
3-3-4 - Vertical geometry
- Adjust the Vertical Amplitude, Shift, S-
Correction and Slope to compensate for vertical
distortion.
3-3-5 - Horizontal picture centering
- Adjust H Shift to have the picture in the center of the screen.
3-3-6 - East / West correction
- Adjust the H Parall, H Bow, H Width, EW Parabo, Up Corner, Dw Corner, EW trapez to
compensate for geometrical distortion.
H. Parall EW.Parabola
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Service Manual CP-785F
3-3-7 - AGC
- Adjust the antenna signal level at 68 dBV 2 (UHF - CH25)
- Set RF AGC to 0.
- Increase RF AGC level and stop when the level on pin 6 of TDA936x goes below 2.5 Vdc
H. Bow
H.Width
Up Corner
Dw Corner
-12-
Service Manual CP-785F
4 - IC description
4-1 TDA936x TV signal processor - Teletext decoder with embedded -Controller.
- TDA936x : TEXT Available
CHASSIS(MODELS) IC MARKING TEXT TV STANDARD
CP-785F TDA9365 10 PAGE TEXT
(DTE-29U1TH) (DW9365/N2) (Pan-Eur opeun) PLA/SECAM
(PF-68T32) (DW9365/CH3)
TV-signal Processor
Multi-standard vision IF circuit with alignment-free PLL demodulator
Internal (switchable) time-constant for the IF-AGC circuit
Source selection between ’Internal’ CVBS and external CVBS or Y/C signals
Integrated chrominance trap circuit
Integrated luminance delay line with adjustable delay time
Asymmetrical delay line type peaking in the luminance channel
Black stretching for non-standard luminance signals
lntegrated chroma band-pass filter with switchable centre frequency
Only one reference (12 MHz) crystal required for the -Controller, Teletext and the colour
decoder
PAL / NTSC or multistandard colour decoder with automatic search system
Internal base-band delay line
RGB control circuit with ’Continuous Cathode Calibration’, white point and black level off set
adjustment so that the colour temperature of the dark and the bright parts of the screen can
be chosen independently.
The Text/OSD signals are internally supplied from the -Controller/Teletext decoder
Contrast reduction possibility during mixed-mode of OSD and Text signals
Horizontal synchronisation with two control loops and alignment-free horizontal oscillator
Vertical count-down circuit
Vertical driver optimised for DC-coupled vertical output stages
Horizontal and vertical geometry processing
Horizontal and vertical zoom function for 16 : 9 applications
Horizontal parallelogram and bow correction for large screen picture tubes
-13-
Service Manual CP-785F
-Controller
80C51 -controller core standard instruction set and timing
1 s machine cycle
32 - 128Kx8-bit late programmed ROM
3 - 12Kx8-bit Auxiliary RAM (shared with Display and Acquisition)
Interrupt controller for individual enable/disable with two level priority
Two 16-bit Timer/Counter registers
WatchDog timer
Auxiliary RAM page pointer
16-bit Data pointer
IDLE and Power Down (PD) mode
14 bits PWM for Voltage Synthesis Tuning
8-bit A/D converter
4 pins which can be programmed as general I/0 pin, ADC input or PWM (6-bit) output
Data Capture
Text memory 10 pages
Inventory of transmitted Teletext pages stored in the Transmitted Page Table (TPT) and
Subtitle Page Table (SPT)
Data Capture for US Closed Caption
Data Capture for 525/625 line WST, VPS (PDC system A) and Wide Screen Signalling
(WSS) bit
decoding Automatic selection between 525 WST/625 WST
Automatic selection between 625 WST/VPS on line 16 of VBI
Real-time capture and decoding for WST Teletext in Hardware, to enable optimised -
processor throughput
Automatic detection of FASTEXT transmission
Real-time packet 26 engine in Hardware for processing accented, G2 and G3 characters
Signal quality detector for video and WST/VPS data types
Comprehensive teletext language coverage
Full Field and Vertical Blanking lnterval (VBI) data capture of WST data
Display
Teletext and Enhanced OSD modes
Features of lever 1.5 WST and US Close Caption
Serial and Parallel Display Attributes
Single/Double/Quadruple Width and Height for characters
Scrolling of display region
Variable flash rate controlled by software
Enhanced display features including overlining, underlining and italics
Soft colours using CLUT with 4096 colour palette
Globally selectable scan lines per row (9/10/13/16) and character matrix [12x10, 12xl3,
12x16 (VxH)]
Fringing (Shadow) selectable from N-S-E-W direction
Fringe colour selectable
Meshing of defined area
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Service Manual CP-785F
Contrast reduction of defined area
Cursor
Special Graphics Characters with two planes, allowing four colours per character
32 software redefinable On-Screen display characters
4 WST Character sets (GO/G2) in single device (e.g. Latin, Cyrillic, Greek, Arabic)
G1 Mosaic graphics, Limited G3 Line drawing characters
WST Character sets and Closed Caption Character set in single device
Data Capture
The Data Capture section takes in the analogue Composite Vid o and Blanking Signal (CVBS),
and from this extracts the required data, which is then decoded and stored in memory.
The extraction of the data is performed in the digital domain. The first stage is to convert the
analogue CVBS signal into a digital form. This is done using an ADC sampling at 12MHz. The
data and clock recovery is then performed by a Multi-Rate Video Input Processor (MuIVIP).
From the recovered data and clock the following data types are extracted WST Teletext
(625/525), Closed Caption, VPS, WSS. The extracted data is stored in either memory (DRAM)
via the Memory Interface or in SFR locations.
Data Capture Features
- Video Signal Quality detector
- Data Capture for 625 line WST
- Data Capture for 525 line WST
- Data Capture for US Closed Caption
- Data Capture for VPS data (PDC system A)
- Data Capture for Wide Screen Signalling (WSS) bit decoding
- Automatic selection between 525 WST/625WST
- Automatic selection between 625WST/VPS on line 16 of VBI
- Real-time capture and decoding for WST Teletext in Hardware, to enable optimised
microprocessor throughput
- 10 pages stored On-Chip
- lnventory of transmitted Teletext pages stored in the Transmitted Page Table (TPT) and
Subtitle Page Table (SPT)
- Automatic detection of FASTEXT transmission
- Real-time packet 26 engine in Hardware for processing accented, G2 and G3 characters
- Signal quality detector for WST/VPS data types
- Comprehensive Teletext language coverage
- Full Field and Vertical Blanking Interval (VBI) data capture of WST data
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Service Manual CP-785F
+8V
13
43
24
23
42
40
CVBS/Y
IFIN
TUNERAGC
SOUND
TRAP
27 37
VIDEO SWITCH
VIDEO IDENT.
VIDEO FILTERS
38
(35) (35)
(32)
28 29 44 31 60 55 59 58 57 2 3 4 9 12
10 PAGE
MEMORY
TELETEXT/OSD
DISPLAY
+3.3V
5654 61
(20)
AUDEXT
SIFIN
QSSOUT/AMOUT
AMOUT
RESET
VPE
LED OUT (2x)
VST OUT
ADC IN (4x)
I/O PORTS (4x)
1+62-64
SCL SDA
5-8
10/11
VISION IF
ALIGNMENT-FREE
PLL DEMOD.
AGC/AFC
VIDEO AMP .
CHROMA
PAL/SECAM/NTSC
DECODER
H/V SYNC SEP.
H-OSC. + PLL
(32)
30
41
18
39
14
19
17
H
34 16 33 25 26 22 21 36
(20) 46 47 48 45
50
49
53
52
51
BLKIN
BCLIN
BO
GO
RO
COR
CONTR/BRIGHTN
OSD/TEXT INSERT
CCC
WHITE-P . ADJ.
HOUT
V-DRIVE
EHTO
EWD
R/V
Y
R
R
V
H
G
G
B
B
BL
RGB/YUV INSERT
RGB/YUV MATRIX
SATURATION
YUV/RGB MATRIX
U
V
G/Y
B/U
BL
V
V-DRIVE +
GEOMETRY
ROM/RAM
CVBS
I
2
C-BUS
TRANSCEIVER
VST PWM-DAC
I/O PROTS
TELETEXT
ACQUISITION
SYNC
EW GEOMETRY
H-DRIVE
2
nd
LOOP
H-SHIFT
BASE-BAND
DELAY LINE
REF
REF
QSS SOUND IF
AGC
QSS MIXER
AM DEMODULTOR
ENIANCED
80C51 CPU
LUMA DELAY
PEAKING
BLACK STRETCH
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Service Manual CP-785F
SYMBOL PIN DESCRIPTION
n.u. 1 Port 1.3 Not used.
SCL 2 I2C bus clock line
SDA 3 I2C Data line
SW2 4 TV, AV1:High
DVD, AV2:Low
OCP 5 Port 3.0 : Over Current Protection
RF AGC in 6 ADC 1 : For factory use only ( High impedance )
Key-in 7 ADC 2 : local key input ( High impedance )
S/W1 8 TV,DVD:High
AV1, AV2:Low
VssC/P 9 digital ground for -controller core and peripheral
LED 1 10 port 0.5 ( 8mA current sinking capability )
LED 2 11 port 0.6 ( 8mA current sinking capability )
VSSA 12 analog ground of teletext decoder and digital ground of TV processor
SEC PLL 13 SECAM PLL decoupling
VP2 14 2nd supply voltage TV-processor
DECDIG 15 decoupling digital supply of TV-processor
PH2LF 16 phase-2 filter
PH1LF 17 phase-1 filter
GND3 18 ground 3 for TV-processor
DECBG 19 bandgap decoupling
AVL/EWD 20 East / West drive output
VDRB 21 vertical drive B output
VDRA 22 vertical drive A output
IFIN1 23 IF input 1
IFIN2 24 IF input 2
IREF 25 reference current input
VSC 26 vertical sawtooth capacitor
TUNERAGC 27 tuner AGC output
SIFIN1 28 SIF input 1
SIFIN2 29 SIF input 2
GND2 30 ground 2 for TV processor
SIF AGC 31 AGC sound IF
REF0 32 n.u.
HOUT 33 horizontal output
FBISO 34 flyback input / sandcastle output
QSS out 35 QSS intercarrier output
EHT0 36 EHT/Overvoltage protection
PLLIF 37 IF PLL loop filter
IFVO 38 IF video output
VP1 39 main supply voltage TV-processor
CVBSINT 40 internal CVBS input
GND1 41 ground 1 for TV-processor
CVBS/Y 42 external CVBS/Y input
CHROMA 43 chrominance input (SVHS)
AMOUT 44 n.u.
PINNING
-17-
Service Manual CP-785F
SYMBOL PIN DESCRIPTION
INSSW2 45 2nd RGB insertion input
Cr 46 DVD-Cr
Y 47 DVD-Y
B2IN 48 DVD-Cb
BCLIN 49 beam current limiter input
BLKIN 50 black current input
R0 51 RED Output
G0 52 GREEN Output
B0 53 BLUE Output
VDDA 54
analog supply of Teletext decoder and digital supply of
TV-Processor (3.3V)
VPE 55 OTP programming supply
VDDC 56 digital supply to core (3.3V)
OSCGND 57 oscillator ground supply
XTALIN 58 crystal oscillator input
XTALOUT 59 crystal oscillator output
RESET 60 reset
VDDP 61 digital supply to periphery (3.3V)
Audio Mute 62 Port 1.0 : Audio mute output (PushPull )
Power 63 Port 1.1 : Power output (PushPull )
IR in 64 Interrupt input 0 : R/C Infrared input
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Service Manual CP-785F
P1.3/T1
P1.6/SCL
P1.7/SDA
P2.0/TPMW
P3.0/ADC0
P3.1/ADC1
P3.2/ADC2
P3.3/ADC3
VSSC/P
P0.5
P0.6
VSSA
SECPLL
VP2
DECDIG
PH2LF
PH1LF
GND3
DECBG
AVL/EWD
VERB
VERA
IFIN1
IFIN2
IREF
VSC
TUNERAGC
AUDEEM/SIFIN1
DECSDEM/SIFIN2
GND2
SNDPLL/SIFAGC
AVL/REFO/AMOUT
P1.2/INT0
P1.1/T0
P1.0/INT1
VDDP
RESET
XTALOUT
XTALIN
OSCGND
VDDC
VPE
VDDA
BO
GO
RO
BLKIN
BCLIN
B2/UIN
G2/YIN
R2/VIN
INSSW2
AUDOUT/AMOUT
CHROMA
CVBS/Y
GND1
CVBSINT
VP1
IFVO/SVO
PLLIF
EHTO
AUDEXT/QSSO/AMOUT
FBISO
HOUT
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
.34
33
MXXxxx
TDA93/6X/8X
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Service Manual CP-785F
4-2 MSP341x Multistandard Sound Processor
The MSP341x is designed as a single-chip Multistandard Sound Processor for applications in
analogue and digital TV sets, video recorders, and PC cards.
MSP 341x features
- sound IF input
- No external filters required
- Stereo baseband input via integrated AD converters
- Two pairs of DA converters
- Two carrier FM or NICAM processing
- AVC : Automatic Volume Correction
- Bass, treble, volume processing
- Full SCART in/out matrix without restrictions
- Improved FM-identification
- Demodulator short programming
- Autodetection for terrestrial TV - sound standards
- Precise bit-error rate indication
- Automatic switching from NICAM to FM/AM or vice versa
- Improved NICAM synchronisation algorithm
- Improved carrier mute algorithm
- Improved AM-demodulation
- Reduction of necessary controlling
- Less external components
Basic Features of the MSP 341x
Demodulator and NICAM Decoder Section
The MSP 341x is designed to simultaneously perform digital demodulation and decoding of
NICAMcoded TV stereo sound, as well as demodulation of FM or AM mono TV sound. Alternatively,
two carrier FM systems according to the German terrestrial specs can be processed with the
MSP 341x.
The MSP 341x facilitates profitable multistandard capability, offering the following advantages:
- Automatic Gain Control (AGC) for analogue input: input range: 0.10 - 3 Vpp
- integrated A/D converter for sound-IF input
- all demodulation and filtering is performed on chip and is individually programmable
- easy realisation of all digital NICAM standards (B/G, I, L and D/K)
- FM-demodulation of all terrestrial standards (include identification decoding)
- no external filter hardware is required
- only one crystal clock (18.432 MHz) is necessary
- high deviation FM-mono mode (max. deviation: approx. –360 kHz)
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Service Manual CP-785F
DSP-Section (Audio Baseband Processing)
- flexible selection of audio sources to be processed
- performance of terrestrial de-emphasise systems (FM, NICAM)
- digitally performed FM-identification decoding and de-matrixing
- digital baseband processing: volume, bass, treble
- simple controlling of volume, bass, treble
Analogue Section
- two selectable analogue pairs of audio baseband input (= two SCART inputs) input level: <2 V
RMS, input impedance: >25 k‰
- one selectable analogue mono input (i.e. AM sound): Not used in this chassis
- two high-quality A/D converters, S/N-Ratio: >85 dB
- 20 Hz to 20 kHz bandwidth for SCART-to-SCART copy facilities
- loudspeaker: one pair of four-fold oversampled D/A converters
output level per channel: max. 1.4 VRMS output resistance: max. 5 k‰
S/N-ratio: >85 dB at maximum volume max. noise voltage in mute mode: < 10 V (BW: 20 Hz...
16 kHz)
- one pair of four-fold oversampled D/A converters supplying a pair of SCART-outputs.
output level per channel: max. 2 V RMS, output resistance: max. 0.5 k‰
S/N-Ratio: >85 dB (20 Hz... 16 kHz)
Application Fields of the MSP 341x
In the following sections, a brief overview about the two main TV sound standards, NICAM 728
and German FM Stereo, demonstrates the complex requirements of a multistandard audio IC.
NICAM plus FM/AM-Mono
According to the British, Scandinavian, Spanish, and French TV-standards, high-quality stereo
sound is transmitted digitally. The systems allow two high-quality digital sound channels to be
added to the already existing FM/AM-channel. The sound coding follows the format of the socalled Near Instantaneous Companding System (NICAM 728). Transmission is performed
using Differential Quadrature Phase Shift Keying (DQPSK. Table below offers an overview of
the modulation parameters.
In the case of NICAM/FM (AM) mode, there are three different audio channels available:
NICAM A, NICAM B, and FM/AM-mono. NICAM A and B may belong either to a stereo or to a
dual language transmission. Information about operation mode and about the quality of the
NICAM signal can be read by the controlling software via the control bus. In the case of low
quality (high bit error rate), the controlling software may decide to switch to the analogue
FM/AM-mono sound. Alternatively, an automatic NICAM-FM/AM switching may be applied.
German 2-Carrier System (DUAL FM System)
Since September 1981, stereo and dual sound programs have been transmitted in Germany
using the 2-carrier system. Sound transmission consists of the already existing first sound
carrier and a second sound carrier additionally containing an identification signal. More details
of this standard are given in Tables below. For D/K very similar system is used.
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Service Manual CP-785F
XTAL_IN
Audio PLL
D/A
D/A
FM1/AM
Demodulator
& NICAM
Decoder
Sound IF
FM2
NICAM A
NICAM B
IDENT
ANA_IN1+
Mono
MONO_IN
SC1_IN_L
SCART1
SC1_IN_R
SC2_IN_L
SCART2
SC2_IN_R
LOUD-
SPEAKER L
LOUDSPEAKER R
D/A
SCART1_L
SCART1_R
SCARTL
SCARTR
SCARTR Switching Facilities
D/A
A/D
A/D
DSP
SCART
SC1_OUT_R
SC1_OUT_L
Loudspeaker
DACM_L
DACM_R
XTAL_OUT
TV standards
TVsystem Position of sound carrier(MHz) Sound modulation Color system Remark
B/G 5.5 / 5.7421875 FM Stereo PAL Applied
B/G 5.5 / 5.85 FM-Mono / NICAM PAL Applied
L 6.5 / 5.85 AM - Mono / NICAM SECAM-L N.A
I 6.0 / 6.552 FM-Mono / NICAM PAL N.A
D/K 6.5 / 6.2578125 D/K1 FM Stereo SECAM-East
6.5 / 6.7421875 D/K2 N.A
6.5 / 5.85 D/K-NICAM FM-Mono / NICAM
Architecture of MSP3415D
Pin connections and short description
Pin No. Pin Name Type Short description
1 TP Out Test pin
2 NC Not Connected
3 NC Not Connected
4 TP Out Test pin
5 TP Out Test pin
6 ADR_SEL In I2C bus Address select
7 STANDBYQ In Standby ( Low-active)
8 NC Not Connected
9 I2C_CL In / Out I2C Clock
10 I2C_DA In / Out I2C data
11 TP In / Out Test pin
12 TP In / Out Test pin
13 TP Out Test pin
14 NC Not Connected
15 TP Out Test pin
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