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

3 - Alignment instructions

8 3-1 Microcontroller configuration : Service mode

8 3-2 Microcnotroller configuration : Option

8 3-3 TV set Alignment

4 - IC description

4-1 TDA936x TV signal processor - TXT with embedded

-Controller 12

4-2 MSP341x Multistandard Sound Processor

4-3 TDA894x J Stereo Audio Amplifier

4-4 TDA835x J Vertical Amplifier

4-5 TDA6107JF

4-6 24C08 8 K bit EEPROM

4-7 STR-F665X

5 - Circuit description

5-1 Block diagram

5-2 IF

5-3 Source switching

5-4

-Controller I/O pin configuration and function 35

5-5 Sound processing

5-6 Sound amplification

5-7 Vertical deflection

5-8 Power supply (STR-F665X)

5-9 TV start-up, TV normal run and stand by mode operations

6 - Service parts list

6-1 Part List

6-2 All Electrical Parts List

6-3 Control Assembly Parts Lists

6-4 Compaitible Components List

7 - Exploded view

8 - PCB Layout

8-1 Main PCB

8-2 AV PCB

9 - Circuit Diagram

-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

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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)

VIDEO

A U D

(MONO)

DVD-Y

OUT DVD IN

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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

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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

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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

CVBS/Y

IFIN

TUNERAGC

SOUND

TRAP

27 37

VIDEO SWITCH

VIDEO IDENT.

VIDEO FILTERS

(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)

34 16 33 25 26 22 21 36

(20) 46 47 48 45

BLKIN

BCLIN

COR

CONTR/BRIGHTN

OSD/TEXT INSERT

CCC

WHITE-P . ADJ.

HOUT

V-DRIVE

EHTO

EWD

R/V

RGB/YUV INSERT

RGB/YUV MATRIX

SATURATION

YUV/RGB MATRIX

G/Y B/U BL

V-DRIVE +

GEOMETRY

ROM/RAM

CVBS

C-BUS

TRANSCEIVER

VST PWM-DAC

I/O PROTS

TELETEXT

ACQUISITION

SYNC

EW GEOMETRY

H-DRIVE

LOOP

H-SHIFT

BASE-BAND

DELAY LINE

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

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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

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

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

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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