R
11AK36-Vestel
-- 11AK36--ltVestel
ManualService
CONTENTS
SAFETY PRECAUTIONS ............................................................................................................................... |
2 |
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PERI-TV SOCKET ......................................................................................................................................... |
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1 |
INTRODUCTION ...................................................................................................................................... |
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2 SMALL SIGNAL PART WITH STV2248: .................................................................................................. |
3 |
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2.1 |
Vision IF Amplifier3 .......................................................................................................................... |
3 |
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2.2 |
QSS Sound Circuit (QSS Versions) ................................................................................................. |
3 |
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2.3 |
AM Demodulator .............................................................................................................................. |
3 |
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2.4 |
FM Demodulator and Audio Amplifier (Mono Versions): .................................................................... |
3 |
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2.5 |
Video Switching ............................................................................................................................... |
3 |
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2.6 |
Synchronization Circuit .................................................................................................................... |
3 |
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2.7 |
Chroma and Luminance Processing: ................................................................................................ |
4 |
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2.8 |
RGB output circu˝t ........................................................................................................................... |
4 |
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2.9 |
µ-Controller ...................................................................................................................................... |
4 |
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3 |
TUNER ................................................................................................................................................... |
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4 |
SOUND OUTPUT STAGE TDA2822 ........................................................................................................ |
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5 VERTICAL OUTPUT STAGE WITH TDA8174A ........................................................................................ |
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6 |
POWER SUPPLY (SMPS) ..................................................................................................................... |
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7 |
DISCRETE VIDEO AMPLIFIER ............................................................................................................... |
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8 SERIAL ACCESS CMOS 8K EEPROM 24C08 ....................................................................................... |
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9 |
SAW FILTERS ........................................................................................................................................ |
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10 IC DESCRIPTIONS AND INTERNAL BLOCK DIAGRAM ...................................................................... |
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10.1 |
ST92195 ....................................................................................................................................... |
6-7 |
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10.2 |
STV224X Video processor: .............................................................................................................. |
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10.3 |
UV1315, UV1316, UV1336 ............................................................................................................ |
8-9 |
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10.4 |
TDA2822 .......................................................................................................................................... |
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10.5 |
TDA8174AW .................................................................................................................................... |
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10.6 |
UC3842/3....................................................................................................................................... |
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10.7 |
E Eprom 24CO8 ............................................................................................................................ |
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Saw filterís list ................................................................................................................................ |
11 |
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GENERAL BLOCK DIAGRAM ........................................................................................................... |
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12 AK36 TITANIUM TELETEXT - Language Groups ................................................................................ |
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13 AK36 CHASSIS MANUAL ADLUSTMENT PROCEDURE .................................................................. |
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SERV›CE ADJUSTMENTS ............................................................................................................ |
15-16 |
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OPTION LIST..................................................................................................................................... |
17 |
15.1 |
OP1 ñ Peripheral Options .............................................................................................................. |
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15.2 |
OP2 ñ Reception Standard Options ............................................................................................... |
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15.3 |
OP3 ñ Video Options ..................................................................................................................... |
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15.4 |
OP4 ñ TV Features ........................................................................................................................ |
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15.5 |
OP5 ñ Channel Tables ................................................................................................................... |
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15.6 |
TX1 ñ Teletext Options ................................................................................................................... |
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16. |
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TUNER SETTING .............................................................................................................................. |
19 |
17 CIRCUIT DIAGRAM of VIDEO PRECESSOR..................................................................................... |
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CIRCUIT DIAGRAM of SMPS ............................................................................................................ |
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CIRCUIT DIAGRAM of MICRO CONTROLLER ................................................................................... |
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CIRCUIT DIAGRAM of VIDEO ............................................................................................................ |
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CIRCUIT DIAGRAM of DEFLECTION ................................................................................................. |
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CIRCUIT DIAGRAM of CRT ................................................................................................................ |
25 |
18 |
WAVEFORMS ...................................................................................................................................... |
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1
DO NOT CHANGE ANY MODULE UNLESS THE SET IS SWITCHED OFF
The mains supply part of the switch mode power supplyís transformer is live.
Use an isolating transformer.
The receiver complies with the safety requirements.
SAFETY PRECAUTIONS
The service of this TV set must be carried out by qualified persons only. Components marked with the warning symbol on the circuit diagram are critical for safety and must only be replaced with an identical component.
-Power resistor and fused resistors must be mounted in an identical manner to the original component.
-When servicing this TV, check that the EHT does not exceed 26kV.
TV set switched off:
Make short-circuit between HV-CRT clip and CRT ground layer.
Short C808 before changing IC841 or other components in primary side of the SMPS part.
Measurements:
Voltage readings and oscilloscope traces are measured under the following conditions:
Antenna signalís level is 60dB at the color bar pattern from the TV pattern generator. (100% white, 75% color saturation) Brightness, contrast, and color are adjusted for normal picture performance.
Mains supply, 220VAC, 50Hz.
PERI-TV SOCKET
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SCART 1 PINING |
1 Audio right output |
0.5Vrms / 1K |
2 Audio right input |
0.5Vrms / 10K |
3 Audio left output |
0.5Vrms / 1K |
4 Ground AF |
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5 Ground Blue |
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6 Audio left input |
0.5Vrms / 10K |
7 Blue input |
0.7Vpp / 75ohm |
8 AV switching input |
0-12VDC /10K |
9 Ground Green |
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10 - |
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11 Green input |
0.7Vpp / 75ohm |
12 - |
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13 Ground Red |
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14 Ground Blanking |
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15 Red input |
0.7Vpp / 75ohm |
16 Blanking input |
0-0.4VDC, 1-3VDC / 75 Ohm |
17 Ground CVBS output |
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18 Ground CVBS input |
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19 CVBS output |
1Vpp / 75ohm |
20 CVBS input |
1Vpp / 75ohm |
21 Ground |
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1 INTRODUCTION
11AK36 is a 90 chassis capable of driving 14î tubes at the appropriate currents. The chassis is capable of operating in PAL, SECAM and NTSC standards. The sound system is capable of giving 3 watts RMS output into a load of 16 ohms. One page and US Closed Caption is also provided. The chassis is equipped with a 21 pin Eu-Scart connector.
2
2 SMALL SIGNAL PART WITH STV2248:
STV2248 video processor is essential for realizing all small signal functions for a color TV receiver.
2.1 Vision IF Amplifier3
The vision IF amplifier can demodulate signals with positive and negative modulation. The PLL demodulator is completely alignment-free. Although the VCO (Toko-coil) of the PLL circuit is external, yet the frequency is fixed to the required value by the original manufacturer thus the Toko-coil does not need to be adjusted manually. The setting of the various frequencies (38.9 or 45.75 MHz) can be made via changing the coil itself.
2.2 QSS Sound Circuit (QSS Versions)
The sound IF amplifier is similar to the vision IF amplifier and has an external AGC de-coupling capacitor. The single reference QSS mixer is realised by a multiplier. In this multiplier the SIF signal is converted to the inter-carrier frequency by mixing it with the regenerated picture carrier from the VCO. The mixer output signal is supplied to the output via a high-pass filter for attenuation of the residual video signals. With this system a high performance hi-fi stereo sound processing can be achieved. The AM sound demodulator is realised by a multiplier. The modulated sound IF signal is multiplied in phase with the limited SIF signal. The demodulator output signal is supplied to the output via a low-pass filter for attenuation of the carrier harmonics. The AM signal is supplied to the output via the volume control.
2.3. AM DEMODULATOR
The AM demodulated signal results from multiplying the input signal by itself, it is available on AM/FM output.
2.4 FM Demodulator and Audio Amplifier (Mono Versions):
The FM demodulator is realized as narrow-band PLL with external loop filter, which provides the necessary selectivity without using an external band-pass filter. To obtain a good selectivity a linear phase detector and constant input signal amplitude are required. For this reason the inter-carrier signal is internally supplied to the demodulator via a gain controlled amplifier and AGC circuit. The nominal frequency of the demodulator is tuned to the required frequency (4.5/ 5.5/6.0/6.5 MHz) by means of a calibration circuit that uses the clock frequency of the µ-controller/Teletext decoder as a reference. The setting to the wanted frequency is realized by means of the software. It can be read whether the PLL frequency is inside or outside the window and whether the PLL is in lock or not. With this information it is possible to make an automatic search system for the incoming sound frequency. This is realized by means of a software loop that alternate the demodulator to various frequencies, then select the frequency on which a lock condition has been found. De-emphasis output signal amplitude is independent of the TV standard and has the same value for a frequency deviation of ±25 kHz at the 4.5 MHz standard and for a deviation of ±50 kHz for the other standards. When the IF circuit is switched to positive modulation the internal signal on de-emphasis pin is automatically muted. The audio control circuit contains an audio switch and volume control. In the mono inter-carrier sound versions the Automatic Volume Leveling (AVL) function can be activated. The pin to which the external capacitor has to be connected depends on the IC version. For the 90 types the capacitor is connected to the EW output pin (pin 20). When the AVL is active it automatically stabilizes the audio output signal to a certain level.
2.5Video Switching
The video processor (STV2248C) has three CVBS inputs and two RGB inputs. The first CVBS input is used for external CVBS from SCART 1, the second is used for either CVBS from FAV, and the third one is used for internal video. The selection between both external video inputs signals is realized by means of software switches.
2.6 Synchronization Circuit
The video processor (STV224X) performs the horizontal and vertical processing. The external horizontal deflection circuit is controlled via the Horizontal output pulse (HOUT). The vertical scanning is performed through an external ramp generator and a vertical power amplifier IC controlled by the Vertical output pulse (VOUT).
The main components of the deflection circuit are:
ïPLL1: the first phase locked loop that locks the internal line frequency reference on the CVBS input signal. It is composed of an integrated VCO (12 MHz) that requires the chroma Reference frequency (4.43MHz or 3.58MHz crystal oscillator reference signal), a divider by 768, a line decoder, and a phase comparator.
ïPLL2: The second phase locked loop that controls the phase of the horizontal output
(Compensation of horizontal deflection transistor storage time variation). Also the horizontal position adjustment is also performed in PLL2.
ïA vertical pulse extractor.
ïA vertical countdown system to generate all vertical windows (vertical synchronization window, frame blanking pulses, 50/ 60Hz identification window...).
ïAutomatic identification of 50/60Hz scanning.
ïPLL1 time constant control.
ïNoise detector, video identification circuits, and horizontal coincidence detector.
ïVertical output stage including de-interlace function, vertical position control.
ïVertical amplitude control voltage output (combined with chroma reference output and Xtal 1 indication).
3
2.7 Chroma and Luminance Processing:
The chroma decoder is able to demodulate PAL, NTSC and SECAM signals.
The decoder dedicated to PAL and NTSC sub-carrier is based on a synchronous demodulator, and an Xtal PLL locked on the phase reference signal (burst).
The SECAM demodulation is based on a PLL with automatic calibration loop. The color standard identification is based on the burst recognition. Automatic and forced modes can be selected through the I2C bus.
NTSC tint, and auto flesh are controlled through I2C bus.
Xtal PLL can handle up to 3 crystals to work in PAL M, PAL N and NTSC M for South America. ACC an ACC overload control the chroma sub-carrier amplitude within 26dB range. Both
ACC s are based on digital systems and do not need external capacitor.
All chroma filters are fully integrated and tuned via a PLL locked on Xtal VCO signal.
A second PLL is used for accurate fine-tuning of the SECAM bell filter. This tuning is achieved during the frame blanking. An external capacitor memorizes the bell filter tuning voltage.
A base-band chroma delay-line rebuilds the missing color line in SECAM and removes transmission phase errors in PAL. The base-band chroma delay line is clocked with 6MHz signal provided by the horizontal scanning VCO.
The luminance processor is composed of a chroma trap filter, a luminance delay line, a peaking function with noise coring feature, a black stretch circuit.
Trap filter and luminance delay lines are achieved with the use of bi-quad integrated filters, auto-aligned via a master filter phase locked loop.
2.8 RGB output circuit:
The video processor performs the R, G, B processing. There are three sources:
1.Y,U,V inputs (coming from luma part (Y output), and chroma decoder outputs (R-Y, B-Y outputs).
2.External R,G,B inputs from SCART (converted internally in Y,U,V), with also the possibility to input YUV signals from a DVD player, (YUV specification is Y=0.7 V PP , U= 0.7 V PP , V = 0.7V PP for 100% color bar).
3.Internal R,G,B inputs (for OSD and Teletext display)
The main functions of the video part are:
-Y,U,V inputs with integrated clamp loop, allowing a DC link with YUV outputs,
-External RGB inputs (RGB to YUV conversion), or direct YUV inputs,
-Y,U,V switches,
-Contrast, saturation, brightness controls,
-YUV to RGB matrix,
-OSD RGB input stages (with contrast control),
-RGB switches,
-APR function,
-DC adjustment of red and green channels,
-Drive adjustments (R, G, B gain),
-Digital automatic cut-off loop control,
-Manual cut-off capability with I2C adjustments,
-Half tone, oversize blanking, external insertion detection, blue screen,
-Blanking control and RGB output stages.
2.9 µ-Controller
The ST92195 is the micro-controller, which is required for a color TV receiver. ST92195D1 is the version with one page Teletext . The IC has the supply voltages of 5 V and they are mounted in PSDIP package with 56 pins.
µ-Controller has the following features
ïDisplay of the program number, channel number, TV Standard, analogue values, sleep timer, parental control and mute is done by OSD
ïSingle LED for standby and on mode indication
ïSystem configuration with service mode
ï3 level logic output for SECAM and Tuner band switching
4
3 TUNER
Either a PLL or a VST tuner is used as a tuner.
UV1316 (VHF/UHF) is used as a PLL tuner. For only PALM/N, NTSC M applications UV 1336 is used as the PLL tuner. UV 1315 (VHF/UHF) is used as a VST Tuner.
Channel coverage of UV1316:
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2))$,5 &+$11(/6 |
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&$%/( &+$11(/6 |
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%$1' |
&+$11(/6 |
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&+$11(/6 |
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5$1*( 0+] |
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5$1*( 0+] |
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/RZ %DQG ( WR & WR 6 WR 6 WR |
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0LG %DQG ( WR ( WR 6 WR 6 WR |
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+LJK %DQG ( WR ( WR 6 WR 6 WR |
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(1). Enough margin is available to tune down to 45.25 MHz. |
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(2). Enough margin is available to tune up to 863.25 MHz. |
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Noise |
Typical |
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Max. |
Gain |
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Min. |
Typical |
Max. |
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Low band |
: 5dB |
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9dB |
All channels |
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: 38dB |
44dB |
52dB |
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Mid band |
: 5dB |
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9dB |
Gain Taper (of-air channels) |
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8dB |
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High band |
: 6dB |
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9dB |
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Channel Coverage UV1336:
%$1' &+$11(/6 )5(48(1&< 5$1*( 0+]
/RZ %DQG WR ' WR
0LG %DQG ( WR 33 WR
+LJK %DQG 444 WR WR
Noise is typically 6dB for all channels. Gain is minimum 38dB and maximum 50dB for all channels.
Channel Coverage of UV1315:
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2))$,5 &+$11(/6 |
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&$%/( &+$11(/6 |
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%$1' |
&+$11(/6 |
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5$1*( 0+] |
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5$1*( 0+] |
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/RZ %DQG ( WR & WR 6 WR 6 WR |
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0LG %DQG ( WR ( WR 6 WR 6 WR |
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+LJK %DQG ( WR ( WR 6 WR 6 WR |
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(1). Enough margin is available to tune down to 45.25 MHz. |
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(2). Enough margin is available to tune up to 863.25 MHz. |
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Noise |
Typ. |
Max. |
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Gain |
Min. |
Typ. |
Max. |
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Low band |
6dB |
9dB |
All Channels |
38dB |
44dB |
50dB |
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Mid band |
6dB |
10dB |
Gain Taper |
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8dB |
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High band |
6dB |
11dB |
(off-air channels) |
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4 SOUND OUTPUT STAGE TDA2822
TDA2822 is used as the AF output amplifier. It is supplied by +12VDC coming from a separate winding in the SMPS transformer. An output power of 3W (THD=10%) can be delivered into an 16 ohm load.
5 VERTICAL OUTPUT STAGE WITH TDA8174A
The TDA8174A is a power amplifier circuit for use in 90 and 110 colour deflection systems for 25 to 200 Hz field frequencies, and for 4 : 3 and 16 : 9 picture tubes.
6 POWER SUPPLY (SMPS)
The DC voltages required at various parts of the chassis are provided by an SMPS transformer controlled by the IC UC3842/ 3 which is designed for driving, controlling and protecting switching transistor of SMPS. The transformer produces 115V for FBT input, ±12V for audio output IC, S+5V and 8V for ST92195.
7 DISCRETE VIDEO AMPLIFIER
Three high voltage, high frequency transistor is used for RGB amplifier. This application works on fixed AC and DC gains.
5
8 SERIAL ACCESS CMOS 8K EEPROM 24C08
The 24C08 is a 8Kbit electrically erasable programmable memory (EEPROM), organized as 4 blocks of 256*08 bits. The memory is compatible with the I C standard, two wire serial interface which uses a bi-directional data bus and serial clock.
9 SAW FILTERS
Saw filter type : |
Model: |
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G1975M |
: |
PAL B/G MONO |
K2966M |
: |
PAL SECAM B/G/D/K/I MONO |
J1981 |
: |
PAL-I MONO |
K2966M |
: |
PAL-SECAM B/G/D/K/I/Ií MONO |
K2962M |
: |
PAL-SECAM B/G/D/K/I/L/Lí MONO |
L9653 |
: |
Secam L/Lí audio |
M1962M |
: |
PAL M/N NTSC M MONO |
IC DESCRIPTIONS AND INTERNAL BLOCK DIAGRAM
ST92195
STV224X
TUNER (UV1315, UV1316, UV1336)
TDA2822
TDA8174A
UC3842/3
24C08
SAW FILTERS
G1975M, K2966M, K2962M, M1962M
10.1 ST92195
The ST92195 is a member of the ST9+ family of micro-controllers, completely developed and produced by SGS-THOMSON Microelectronics using a proprietary n-well HCMOS process. The nucleus of the ST92195 is the advanced Core, which includes the Central Processing Unit (CPU), the ALU, the Register File and the interrupt controller. The Core has independent memory and register buses to add to the efficiency of the code. A set of on-chip peripherals form a complete sys-tem for TV set and VCR applications:
Voltage Synthesis
VPS/WSS Slicer
Teletext Slicer
Teletext Display RAM
OSD
Additional peripherals include a watchdog timer, a serial peripheral interface (SPI), a 16-bit timer and an A/D converter.
6
X &21752//(5 9(56¯21 7$%/(
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12 7;7 0212 |
,& 67 % 6: % |
3 0212 |
,& 67 & . 6: ' |
3 0212 675 |
,& 67 & . 6: ( |
3 0212 675 :66 |
,& 67 & . 6: ) |
3 0212 675 $36 :66 |
,& 67 & . 6: * |
10.2 STV224X Video processor:
The STV2246/2247/2248 are fully bus controlled ICs for TV including PIF, SIF, luma, Chroma and deflection processing. Used with a vertical frame booster (TDA1771 or TDA8174 for 90 chassis, STV9306 for 110 chassis), they allow the design of multi-standard (BGDKIMNLL, PAL/ SECAM/NTSC) sets with very few external components and no manual adjustments.
9,'(2 352&(6625 ,& 7$%/( |
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0212 |
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3$/ |
6(&$0 |
176& |
679 |
2. |
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2. |
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2. |
679 |
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2. |
2. |
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2. |
679 |
2. |
2. |
2. |
2. |
2. |
7
10.3 UV1315, UV1316, UV1336
General description of UV1315:
The UV1315 tuner belongs to the UV 1300 family of tuners, which are designed to meet a wide range of applications. It is a combined VHF, UHF tuner suitable for CCIR systems B/G, H, L, Lí, I and Ií.
Features of UV1315:
Member of the UV1300 family small sized UHF/VHF tuners
Systems CCIR:B/G, H, L, Lí, I and Ií; OIRT:D/K
Voltage synthesized tuning (VST)
Off-air channels, S-cable channels and Hyper-band
Standardized mechanical dimensions and pinning
PINNING |
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PIN VALUE |
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1. |
Gain control voltage (AGC) |
: |
4.0V, Max:4.5V |
2. |
Tuning voltage |
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3. |
High band switch |
: |
5V, Min:4.75V, Max:5.5V |
4. |
Mid band switch |
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5V, Min:4.75V, Max:5.5V |
5. |
Low band switch |
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5V, Min:4.75V, Max:5.5V |
6. |
Supply voltage |
: |
5V, Min:4.75V, Max:5.5V |
7.Not connected
8.Not connected
9.Not connected
10.Symmetrical IF output 1
11.Symmetrical IF output 2
Band switching table:
%$1' 3,1 3,1 3,1
/RZ %DQG 9 9 9
0LG %DQG 9 9 9 +LJK %DQG 9 9 9
General description of UV1316:
The UV1316 tuner belongs to the UV 1300 family of tuners, which are designed to meet a wide range of applications. It is a combined VHF, UHF tuner suitable for CCIR systems B/G, H, L, Lí, I and Ií.
Features of UV1316:
Member of the UV1300 family small sized UHF/VHF tuners
Systems CCIR: B/G, H, L, Lí, I and Ií; OIRT: D/K
Digitally controlled (PLL) tuning via I C-bus
Off-air channels, S-cable channels and Hyper-band
World standardized mechanical dimensions and world standard pinning
Complies to ìCENELEC EN55020î and ìEN55013î
PINNING |
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PIN VALUE |
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1. |
Gain control voltage (AGC) |
: |
4.0V, Max:4.5V |
2. |
Tuning voltage |
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3. |
I C-bus address select |
: |
Max:5.5V |
4. |
I C-bus serial clock |
: |
Min:-0.3V, Max:5.5V |
5. |
I C-bus serial data |
: |
Min:-0.3V, Max:5.5V |
6. |
Not connected |
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7. |
PLL supply voltage |
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5.0V, Min:4.75V, Max:5.5V |
8. |
ADC input |
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9. |
Tuner supply voltage |
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33V, Min:30V, Max:35V |
10.Symmetrical IF output 1
11.Symmetrical IF output 2
8
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