11AK19
is a 90 and 110 chassis capable of driving 20, 21,24,25,28,29,32,33 inch tubes at appropriate currents.
The
chassis is capable of working in both PAL and SECAM. The sound system is
capable of giving 6watts RMS output into a load of 8ohms.
One
8 page simple TELETEXT, TOPTEXT and FASTEXT is provided.
The
chassis is equipped with 21-pin scart connectors which can accept via scart the
SVHS format from VCRs so equipped.
SMALL SIGNAL PART WITH TDA884X
The
TDA8840/8842/8844 combine all small signal functions required for a colour TV
receiver, except tuning.
Vision IF amplifier
The
IF-amplifier contains 3 AC-coupled control stages with a total gain control range
which is higher than 66dB.
The
sensitivity of the circuit is comparable with that of modern IF-IC’ s. The
video signal is demodulated by means of a PLL carrier regenerator. This circuit
contains a frequency detector and a phase detector. The AFC output is obtained
by using the VCO control voltage of the PLL and can be read via the I2C-bus.
For fast search tuning systems the window of the AFC can be increased with a
factor 3. The setting is realised with the AFW bit.
Depending
on the type the AGC-detector operates on top-sync level (single standard
versions) or on top sync and top white-level (multi standard versions). The
demodulation polarity is switched via the I2C-bus. The AGC detector
time-constant capacitor is connected externally. This mainly because of the
flexibility of the application. The time-constant of the AGC system during
positive modulation is rather long to avoid visible variations of the signal
amplitude. To improve the speed of the AGC system a circuit has been included
which detects whether the AGC detector is activated every frame period. When
during 3 frame periods no action is detected the speed of the system is
increased. For signals without peak white information the system switches
automatically to a gated black level AGC. Because a black level clamp pulse is
required for this way of operation the circuit will only switch to black level
AGC in the internal mode.
The
circuits contain a video identification circuit which is independent of the
synchronisation circuit. Therefore search tuning is possible when the display
section of the receiver is used as a monitor. The ident output is supplied to
the tuning system via the I2C-bus. The video ident circuit can be made less
sensitive by means of the STM bit. This mode can be used during search tuning
to avoid that the tuning system will stop at very weak input signals.
Video
Switches
The
circuits have two CVBS inputs (internal and external CVBS) and Y/C input. When
the Y/C input is not required the Y input can be used as third CVBS input. The
selection of the various sources is made via the I†C-bus. The circuit has one
CVBS output.
Sound
Circuit
The
sound band pass and trap filters have to be connected externally. The filtered
intercarrier signal is fed to a limiter circuit and is demodulated by means of
a PLL demodulator. This PLL circuit tunes itself automatically to the incoming
carrier signal so that no adjustment is required.
The
volume is controlled via the I2C-bus. The de-emphasis capacitor has to be
connected externally. The non-controlled audio signal can be obtained from this
pin. The FM demodulator can be muted via the I2C-bus. This function can be used
to switch-off the sound during a channel change so that high output peaks are
prevented. The TDA8840/8842 contain an automatic volume levelling (AVL) circuit
which automatically stabilises the audio output signal to a certain level which
can be set by the viewer by means of the volume control. This function prevents
big audio output fluctuations due to variations of the modulation depth of the
transmitter. The AVL function can be
activated via the I2C-bus.
Synchronisation
circuit
The
sync separator is preceded by a controlled amplifier which adjusts the sync
pulse amplitude to a fixed level. These pulses are fed to the slicing stage which
is operating at 50% of the amplitude. The separated sync pulses are fed to the
first phase detector and to the coincidence detector. This coincidence detector
is used to detect whether the line oscillator is synchronised and can also be
used for transmitter identification. The first PLL has a very high statical
steepness so that the phase of the picture is independent of the line
frequency.
The
horizontal output signal is generated by means of an oscillator which is
running at twice the line frequency. Its frequency is divided by 2 to lock the
first control loop to the incoming signal. The time-constant of the loop can be
forced by the I†C-bus (fast or slow).
If
required the IC can select the time-constant depending on the noise content of
the incoming video signal.
To
protect the horizontal output transistor, the horizontal drive is immediately
switched off when a power-on-reset is detected.
The
drive signal is switched-on again when the normal switch-on procedure is
followed.
Via
the I2C-bus, adjustments can be made of the horizontal and vertical geometry.
The vertical saw tooth generator drives the vertical output drive circuit which
has a differential output current. For the EW drive a single ended current
output is available.
When
the horizontal scan is reduced to display 4 : 3 pictures on a 16 : 9 picture
tube an accurate video blanking can be switched on to obtain well defined edges
on the screen.
Overvoltage
conditions can be detected via the EHT tracking pin. When an overvoltage
condition is detected the horizontal output drive signal will be switched-off
via the slow stop procedure but it is also possible that the drive is not
switched-off and that just a protection indication is given in the IC-bus
output byte. The choice is made via the input bit PRD.
Chroma and Luminance processing
The
circuits contain a Chroma band pass and trap circuit. The filters are realised
by means of gyrator circuits and they are automatically calibrated by comparing
the tuning frequency with the X-tal frequency of the decoder.
The
luminance delay line and the delay for the peaking circuit are also realised by
means of gyrator circuits.
The
centre frequency of the Chroma band pass filter is switchable via the I†C-bus
so that the performance can be optimised for “front-end” signals and external
CVBS signals.
During
SECAM reception the centre frequency of the Chroma trap is reduced to get a
better suppression of the SECAM carrier frequencies.
Colour
Decoder
The
decoder contains an alignment-free X-tal oscillator, a killer circuit and two
colour difference demodulators. The 90° phase shift for the reference signal is
made internally.
The
IC contains an automatic colour limiting (ACL) circuit which prevents that
oversaturation occurs when signals with a high Chroma-to-burst ratio are
received. The ACL circuit is designed such that it only reduces the chroma
signal and not the burst signal. This
has the advantage that the colour sensitivity is not affected by this
function. The base-band delay line is
integrated in the PAL/SECAM IC’ s.
The
demodulated colour difference signals are internally supplied to the delay
line. The matrixed signals are externally available. The colour difference matrix switches
automatically between PAL/SECAM and NTSC, however, it is also possible to fix
the matrix in the PAL standard.
Which
colour standard the IC can decode depends on the external X-tals. The X-tal to
be connected to pin 34 must have a frequency of 3.5 MHz (NTSC-M, PAL-M or
PAL-N) and pin 35 can handle X-tals with a frequency of 4.4 and 3.5 MHz. To
prevent calibration problems of the horizontal oscillator the external
switching between the 2 X-tals should be carried out when the oscillator is forced
to pin 35. For a reliable calibration of the horizontal oscillator it is very
important that the X-tal indication bits (XA and XB) are not corrupted. For
this reason the X-tal bits can be read in the output bytes so that the software
can check the I†C-bus transmission.
RGB
output circuit and black-current stabilisation
The
colour-difference signals are matrixed with the luminance signal to obtain the
RGB-signals. The TDA 884X device has one linear RGB input. This RGB signal can
be controlled on contrast and brightness.
The
output signal has amplitude of about 2 volts black-to-white at nominal input
signals and nominal settings of the controls.
To
increase the flexibility of the IC it is possible to insert OSD and/or teletext
signals directly at the RGB outputs.
This
insertion mode is controlled via the insertion input (pin 26 in the S-DIP 56-
and pin 38 in the QFP-64 level). This blanking action at the RGB outputs has
some delay which must be compensated externally.
To
obtain an accurate biasing of the picture tube a Continuous Cathode
Calibration circuit has been developed.
This
function is realised by means of a 2-point black level stabilisation circuit.
When
the TV receiver is switched-on, the RGB output signals are blanked and the
black current loop will try to set the right picture tube bias levels. Via the
AST bit a choice can be made between automatic start-up or a start-up via the
m-processor.
VIDEO
SWITCH TEA6415C
In
case of three or more external sources are used, the video switch IC TEA6415C
is used. The main function of this device is to switch 8 video input sources on
the 6 outputs.
Each
output can be switched on only one of each input. On each input an alignment of
the lowest level of the signal is made (bottom of sync. top for CVBS or black level
for RGB signals).
Each
nominal gain between any input and output is 6.5dB.For D2MAC or Chroma signal
the alignment is switched off by forcing, with an external resistor bridge,
5VDC on the input. Each input can be used as a normal input or as a MAC or
Chroma input (with external resistor bridge). All the switching possibilities
are changed through the BUS.
Driving
75ohm load needs an external resistor.
It is possible to have the same input connected to several outputs.
AM
DEMODULATOR TDA9830
The
TDA9830 is designed for AM-sound demodulation used in L and L’ standard.
Sound
IF Input:
The
sound IF amplifier consists of three AC-coupled differential amplifier stages
each with approximately 20dB gain.
At
the output of each stage is a multiplier for gain controlling. The overall
control range is approximately -6 to +60dB and the frequency response (-3dB) of
the IF amplifier is approximately 6 to 70MHz. The steepness of gain control is
approximately 10mV/dB.
IF
AGC:
The
automatic gain control voltage to maintain the AM demodulator output signal at
a constant level is generated by a mean level detector.The AGC-detector charges
and discharges the capacitor at pin 3 controlled by the output signal of the
AM-demodulator compared to an internal reference voltage. The maximum
charge/discharge current is approximately 5 mA.
AM-demodulator
The
IF amplifier output signal is fed to a limiting amplifier (two stages) and to a
multiplier circuit.
However
the limiter output signal (which is not any more AM modulated) is also fed to
the multiplier, which provides AM demodulation (in phase demodulation). After
lowpass filtering (fg @ 400kHz) for carrier rejection and buffering, the
demodulator output signal is present at pin 6.
Audio
Switch
This
circuit is an operational amplifier with three input stages and internal
feedback network determining gain (0dB) and frequency response (fg @ 700kHz).
Two of the input stages are connected to pin 7 and pin 9, the third input stage
to an internal reference voltage. Controlled by the switching pins 10 and 12,
one of the three input stages can be activated and a choice made between two
different AF signals or mute state. The selected signal is present at pin 8.
The decoupling capacitors at the input pins are needed, because the internally generated
bias voltage for the input stages must not be influenced by the application in
order to avoid DC-plop in case of switching.
Reference
Circuit:
This
circuit is a band gap stabiliser in combination with a voltage regulation
amplifier, which provides an internal reference voltage of about 3.6V nearly
independent from supply voltage and temperature. This reference voltage is
filtered by the capacitor at pin 4 in order to reduce noise. It is used as a
reference to generate all important voltages and currents of the circuit. For application in 12V power supply concepts,
there is an internal voltage divider in combination with a Darlington
transistor in order to reduce the supply voltage for all IC function blocks to
approximately 6V.
DIGITAL
TV SOUND PROCESSOR TDA9875
The
TDA9875 is a single-chip Digital TV Sound Processor. Supported standards are M, B/G, D/K, I and L.
Description
of the demodulator and decoder section:
SIF
Input:
Two
input pins are provided, SIF1 e.g. for terrestrial TV and SIF2 e.g. for a
satellite tuner. The selected signal is passed through an AGC circuit and then
digitized by an 8-bit ADC operating at 24.576MHz.
AGC:
The
gain of the AGC amplifier is controlled from the ADC output by means of a
digital control loop employing hysteresis.
The AGC has a fast attack behaviour to prevent ADC overloads and slow
decay behaviour AGC oscillations. For AM
demodulation AGC must be switched off.
Mixer
The
digitized input signal is fed to the mixers, which mix one or both input sound
carriers down to zero IF. A 24-bit control word for each carrier sets the
required frequency.
FM
and AM Demodulation
An
FM or AM input signal is fed via a band-limiting filter to a demodulator that
can be used for either FM or AM demodulation.
Apart from the standard (fixed) de-emphasis characteristic, an adaptive
de-emphasis is available for encoded satellite programs. A stereo decoder recovers the left and right
signal channels from the demodulated sound carriers.
FM
Identification:
The
identification of the FM sound mode is performed by AM synchronous demodulation
of the pilot signal and narrow-band detection of the identification
frequencies. The result is available via the I†C-bus interface.
NICAM
Demodulation:
The
NICAM signal is transmitted in a DQPSK code at a bit rate of 728 kbit/s. The
NICAM demodulator performs DQPSK demodulation and feeds the resulting bitstream
and clock signal onto the NICAM decoder and, for evaluation purposes, to PCLK
(pin 1) and NICAM (pin 2).
NICAM
Decoder:
The
device performs all decoding functions in accordance with the “EBU NICAM 728
specification”. After locking to the frame alignment word, the data is
descrambled by applying the defined pseudo-random binary sequence; the device
will then synchronise to the periodic frame flag bit C0.
The
status of the NICAM decoder can be read out from the NICAM status register by
the user. The OSB bit indicates that the decoder has locked to the NICAM data.
The VDSP bit indicates that the decoder has locked to the NICAM data and that
the data is valid sound data.
SOUND
OUTPUT STAGE TDA2614/TDA2615/TDA2616Q
TDA2615
is used as the AF output amplifier for stereo applications. It is supplied by
–12VDC coming from a separate winding in the SMPS transformer. An output power
of 2*6W (THD=0.5%) can be delivered into an 8ohm load.
TDA2616Q
is used as the AF output amplifier for stereo and dolby prologic applications.
It is supplied by –16VDC coming from a separate winding in the SMPS
transformer. An output power of 2*12W (THD=0.5%) can be delivered into an 8ohm
load.
TDA2614
is used as the AF output amplifier for mono applications. It is supplied by
–12VDC coming from a separate winding in the SMPS transformer. An output power
of 2*6W (THD=0.5%) can be delivered into an 8ohm load.
VERTICAL
OUTPUT STAGE WITH TDA8351/8356
The
TDA8351/8356 vertical deflection circuit can be used in 90° and 110° deflection
systems with field frequencies from 50 up to 120Hz. With its bridge
configuration the deflection output can be DC coupled with few external
components.
Only
a single supply voltage for the scan and a second supply for the fly back are
needed. The TDA8356 is intended for 90° systems and the TDA8351 is intended for
110° systems. The drive voltage is
amplified by an amplifier and fed to two amplifiers, one is inverting and the
other is a non inverting amplifier.
The
outputs (pins 7 and 4) are connected to the series connection of the vertical
deflection coil and feedback resistor Rsense (R702//R703). The voltage across
Rsense is fed via pin 9 to correction amplifier, to obtain a deflection current
which is proportional to the drive voltage. The supply voltage for the
TDA8351/8356 is 15VDC at pin 3. The supply voltage generator has a separate
supply voltage of 45VDC at pin 6.
VIDEO
OUTPUT AMPLIFIER TDA6107Q
The
TDA6107Q consists of three monolithic video output amplifiers. The amplifier
can be seen as an operational amplifier with negative feedback.
The
advantage of negative feedback is that the amplifier characteristics do not
play an important role up to certain frequencies. The internal flash diodes protect the
amplifiers against flash over in the picture tube. The only protections required at the cathode
outputs are a flash resistor and a spark gap.
The
TDA6107Q has an internal thermal protection circuit which gives a decrease of
the slew rate at high temperatures.
Furthermore,
the device needs only one power supply voltage (Vdd).
In
contrast to previous types of DMOS video amplifiers, all the external resistors
(Rf, Ri and Ra) are integrated, so the gain is fixed and saves 9 resistors.
Furthermore,
the reference voltage is integrated, it saves a resistor divider and a
decoupling capacitor. So, the replacement value of the TDA6107Q is very high.
The
TDA6107Q is provided with a black current data pin. Since TDA884X is used as
drive device, no adjustments are required for gain and black setting, as the
TDA884X has I†C white point adjustment and black current set-up.
SINGLE/MULTISTANDARD
VIF/SIF-PLL and FM-PLL/AM DEMODULATOR TDA9818
The
TDA9818is an IC for multistandard vision IF signal processing, sound AM and FM
demodulation.
It
is a gain controlled wide band VIF-amplifier (AC-coupled). It is applicable for
IF frequencies of 38.9 MHz, 45.75 MHz and 58.75 MHz. True synchronous
demodulation is provided with active carrier regeneration. It has a VCO
frequency which can be switchable between L and L accent (alignment external)
picture carrier frequency. The TDA9818
has a SIF input for single reference QSS mode (PLL controlled). SIF AGC
detector is to provide gain controlled SIF amplifier. The AM demodulator is
without extra reference circuit. The supply voltage is +5VDC at pin 21.
COMBFILTER
SAA4961
The
SAA 4961 is a one-chip, PAL/NTSC comb filter IC with internal delay lines,
filters, clock control, synchronisation and signal switches. The comb filter
function is realised in a switched capacitor technique, so it has time discrete
but amplitude continuous processing.
The
Y/CVBS input is first clamped and then fed to the delay-line and comb filter
section via a low pass pre-filter.
This
filter can be bypassed via the external LPF-on pin. This pin is internally
pulled up, to put the filter default on. The Y/CVBs input is also fed to the
sync separator, where horizontal and vertical reference pulses are made.
Bypass
mode can be forced via BYP (pin 3).FSC (pin 1) is the subcarrier input which is
connected to the colour decoder. Input
FSCSW pin indicates if fsc or 2*fsc is used.
The
Sys1,2 pins (20, 23) indicate which system standard is processed. Sys2 is
internally pulled up, Sys1 is internally pulled down.
Therefore
when the Sys1,2 inputs are left open, automatically PAL 4.43MHz is forced.
SAA4961output
pin 15 “CVBS” can be used for parallel-synced teletext decoders, to guarantee
that the teletext display always has a correct timing relation with the main
picture. Comb filter is disabled by setting SAA4961 pin 3 “BYP” high.
POWER
SUPPLY (SMPS)
The
DC voltages required at various parts of the chassis are provided by an SMPS
transformer controlled by the IC MC44604 which is designed for driving,
controlling and protecting switching transistor of SMPS. The transformer
produces 150/115V for FBT input, –14V for audio output IC, S+5V for
microcontroller, +15V for vertical output (field scan) and +33V for tuner and
some other ICs and transistors.
MICROCONTROLLER
SDA525X
The
device is TV TEXT tuning and control system based on the SDA 525X TV TEXT
microcontroller. It is designed for a low cost mono TV-SET with analogue
picture and sound control. Neverthless the system offers an on screen display
(OSD) and IR remote control of all functions.
SDA525X
has the following features:
-
Display of program number, channel number, TV standard, analogue values, sleep
timer, parental control, and mute is done by OSD.
-
Single LED for IR active, standby and on mode indication.
-
1 Control line to select external source.
-
3 Control lines for TV standard selection.
-
Frequency synthesis tuning (62.5 kHz steps)
-
192 step fine tuning
-
Channels corresponding to standards B/G, OIRT, L and I (I+)
-
Mono sound control by analogue voltage
-
System configuration with service mode.
SERIAL
ACCESS CMOS 8K (1024*8) EEPROM ST24C08
The
ST24C08 is a 8Kbit electrically erasable programmable memory (EEPROM),
organised as 4 blocks of 256*8 bits.
The
memory is compatible with the I†C standard, two wire serial interface which
uses a bi-directional data bus and serial clock. The memory carries a built-in 4 bit, unique
device identification code (1010) corresponding to the I†C bus definition. This is used together with 1 chip enable
input (E) so that up to 2*8K devices may be attached to the I†C bus and
selected individually.
CLASS
AB STEREO HEADPHONE DRIVERTDA1308
The
TDA1308 is an integrated class AB stereo headphone driver contained in a DIP8
plastic package. The device is
fabricated in a 1 mm CMOS process and has been primarily developed for portable
digital audio applications.
SAW
FILTERS
Saw
filter type : Model:
G1965M
: PAL-SECAM B/G MONO
G3962M
: PAL-SECAM B/G GER&NIC STEREO, PAL I’ NIC STEREO, INT-1
G1984
: PAL-SECAM B/G GER&NIC STEREO INT-2
J1951M
: PAL-I MONO
J3950M
: PAL-I NIC STEREO
J1956M
: PAL-I MONO
K2955M
: PAL-SECAM B/G-D/K MONO, PAL-SECAM B/G-D/K-I’, MONO, PAL-SECAM B/G-D/K-L MONO
K2958M
: PAL-SECAM B/G-D/K (38) MONO
K2962M
: PAL-SECAM B/G-L/L’ MONO
G3957M
: PAL-SECAM B/G-L/L’ GER&NIC BG/L STEREO
K6256K
: PAL-SECAM B/G-D/K-I-L/L’ MONO, PAL-SECAM B/G-D/K-I, L/L’ GER&NIC BG/L
STEREO,
PAL-SECAM
B/G-D/K-I-L/L’ I, NICAM STEREO, PAL-SECAM B/G-D/K-I-L/L’ GER&NIC I B/G-L,
STEREO
K6259K
: PAL-SECAM B/G-D/K-I-M/N (EURO) MONO
M1963M
: PAL M/N MONO, NTSC M MONO, PAL M/N-NTSC M MONO
BTSC
STEREO/SAP/DBX-DECODER and AUDIO PROCESSOR TDA9855
The
TDA9855 is a BTSC stereo/SAP/dbx decoder and audio processor. It performs all
functions to transform the composite baseband signal into the appropriate audio
output signals to line out and to the loudspeaker output stages.
TDA8840/8842/8844:
The
TDA884X is IýC-bus controlled single chip TV processor which is intended to be
applied in PAL, NTSC, PAL/NTSC and multi-standard television receivers. These
IC’ s are nearly pin compatible with the TDA837X TV processors but have a
higher degree of integration because the delay line (TDA4665 function) and the
SECAM decoder have been integrated. In addition to these functions some
additional features have been added like “Continuous Cathode Calibration (2-point black current loop which results in an accurate biasing of the 3
guns), adjustable luminance delay time, blue stretching and dynamic skin tone
control. 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, L’, I and I’.
The low IF output impedance has been designed for direct drive of a wide
variety of SAW filters with sufficient suppression of triple transient. 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, L’, I and I’.
The low IF output impedance has been designed for direct drive of a wide
variety of SAW filters with sufficient suppression of triple transient.
TEA6415C:
General
Description:
The
main function of the TEA6415C is to switch 8 video input sources on the 6
outputs. Each output can be switched to
only one of the inputs whereas but any same input may be connected to several
outputs.
All
switching possibilities are controlled through the I2C-bus.
TDA9830:
General
description:
The
TDA9830, a monolithic integrated circuit, is designed for AM-sound demodulation
used in L- and L’-standard. The IC
provides an audio source selector and also mute switch.
TDA2614/TDA2615/TDA2616Q:
General
Description of TDA2614:
The
TDA2614 is a power amplifier in a 9-lead single-in-line (SIL9) plastic medium
power package. It has been especially designed for mains fed applications.
General
Description of TDA2615:
The
TDA2615 is a dual power amplifier in a 9-lead single-in-line (SIL9). It has
been especially designed for mains fed applications.
General
Description of TDA2616Q:
The
TDA2616Q is a dual power amplifier. It is supplied in a 9-lead SIL-bent-to DIL
plastic power package (SOT157). It has
been especially designed for mains fed applications.
TDA8351/8356:
General
Description:
The
TDA8356 is a power circuit for use in 90ł colour deflection system for field
frequencies of 50 to 120 Hz. The circuit
operates as a highly efficient class G system.
The
TDA8351 is a power circuit for use in 110ł colour deflection system for field
frequencies of 50 to 120 Hz. The circuit
operates as a highly efficient class G system.
TDA6107Q:
The
TDA6107Q includes three video output amplifiers in a SIL 9 MP (Single In Line 9
pins Medium Power) package SOT111BE, using high-voltage DMOS technology, and is
intended to drive the three cathodes of a colour picture tube.
In
contrast to previous types of DMOS video amplifiers, all external resistors
(Rf, Ri and Ra) are integrated, so the gain is fixed and it saves 9 resistors.
To
obtain maximum performance, the amplifier should be used with black-current
control and mounted on the CRT panel.
SAA4961:
The
SAA4961 is an adaptive alignment-free one chip comb filter compatible with both
PAL and NTSC systems and provides high performance in Y/C separation.
It
is possible to switch the comb filter into one of the following 3 modes:
1.
Comb mode : In this mode, luminance and chrominance comb filter function are
active. Chrominance output pin (pin 12)
outputs comb filtered chrominance signal, luminance output pin (pin 14) outputs
comb filtered luminance signal and CVBS output pin (pin 15) outputs delay
compensated CVBS signal.
2.
Comb off mode : In this mode, luminance comb filter function is turned off, but
chrominance comb filter function operates.
Chrominance output pin (pin 12) outputs comb filtered chrominance
signal, luminance output pin (pin 14) outputs delay compensated CVBS signal and
CVBS output pin (pin 15) outputs delay compensated CVBS signal.
3.
Bypass mode: In this mode, no IC-function is active. Cext is bypassed to
chrominance output pin (pin 12) and Yext/CVBS is bypassed to luminance output
pin (pin 14) and CVBS output pin (pin 15).
MC44604:
General
description:
The
MC44604 is an enhanced high performance controller that is specifically
designed for off-line and DC-to-DC converter applications. It offers a really safe and reliable power
management thanks particularly to its protection features (foldback,
overvoltage detection, soft start, accurate demagnetization detection). Its
high current totem pole output is also ideally suited for driving a power MOSFET,
but can also be used for driving a bipolar transistor in low power converters.
In addition to these features, the MC44604 offers an efficient stand-by mode.
SDA525X:
General
description:
The
SDA525X is designed for a low cost mono TV-set with analogue picture and sound
control. IN SDA525X the following IC’ s are used and supported:
Non-volatile
memory : SDA 2526 or SDA2546
PLL
: SDA 3202-3, SDA 3302
IR
transmitter: SDA 2208-3 or SDA 2218
IR
preamplifier: SFH 506-32
TDA9875:
General
description:
The
TDA9875 is a single-chip Digital TV Sound Processor (DTVSP) for analogue and
digital multi-channel sound systems.
TDA9818:
General
description:
The
TDA9818 is an integrated circuit for multistandard vision IF signal processing,
sound AM and FM demodulation.
ST24C08:
The
ST24C08 is a 8Kbit electrically erasable programmable memory (EEPROM),
organized as 4 blocks of 256 * 8 bits.
The memory operates with a power supply value as low as 2.5V. Both
Plastic Dual-in-Line and Plastic Small Outline packages are available.
TDA9855
General
description:
The
TDA9855 is a bipolar-integrated BTSC stereo/SAP decoder with hi-fi audio
processor (IýC-bus controlled) for application in TV sets.
11AK19
CHASSIS MANUAL ADJUSTMENTS PROCEDURE
In
order to enter the service mode, first enter the installation menu (or press
blue button on the remote control handset) and then press the digits 4, 7, 2 and 5
respectively.
For
ADJUST settings:
Select
Adjust using DN or UP button and press RIGHT or LEFT button to enter it. To
select different adjust parameters, use DN or UP button. To change the selected parameter, use LEFT or
RIGHT button.
WHITE
BALANCE ADJUSTMENT:
The
following three parameters are used to make white balance adjustment. To do
this, use a Colour Analyser. Using white point RED, white point GREEN and white
point BLUE parameters, insert the + sign in the square which is in the middle
of the screen.
ADJUST
00 = White Point RED
ADJUST
01 = White Point GREEN
ADJUST
02 = White Point BLUE
AGC
ADJUSTMENT:
In
order to do AGC adjustment, enter a 60dBmV RF signal level from channel C-12.
Connect
a digital voltmeter to pin 1 of the tuner. Change the AGC parameter until you
see 3.70VDC on voltmeter display. Check that picture is normal at 90dBmV signal
level.
IF-PLL
NEGATIVE ADJUSTMENT (Only with PLL tuner):
Connect
38.9 MHz test pattern for PAL B/G, PAL-SECAM B/G, 39.5 MHz test pattern for PAL
I or 45.75 MHz test pattern for PAL M/N, NTSC M model to Z401 SAW filter input
terminals. Change the IF-PLL Negative parameter until you see IN, DOWN below.
If you cannot catch IN, DOWN position this way, using a screwdriver rotate the
VIF-COIL LT401 left or right until you see IN, DOWN.
IF-PLL
POSITIVE ADJUSTMENT (Only with PLL tuner):
Connect
33.9 MHz test pattern for SECAM L’ model to Z401 SAW filter input terminals.
Change the IF-PLL Positive parameter until you see IN, DOWN below. If you
cannot catch IN, DOWN position this way, using a screwdriver rotate the VIF-COIL
LT401 left or right until you see IN, DOWN.
LUMINANCE
DELAY ADJUSTMENT (with only TDA 8844 video processor):
Y-Delay
PAL
Enter
a PAL B/G colour and black-white bar test pattern via RF. Adjust Y-Delay PAL
till the colour transients on the colour bar of the pattern become as sharper
and colours between transients do not mix with each other as possible.
Note:
If the SAW filter is one of the G1965M, J1951M, J3950M, K2958M, K2962M, G3957M,
K6256K, K6259K or M1963M, there is constant group delay distortion, so for an
equal delay of the luminance and chrominance signal the delay must be set at a
value of 160nS. This means the adjustment must be set to the maximum value.
Y-Delay
SECAM
Enter
a SECAM B/G colour and black-white bar test pattern via RF. Adjust Y-Delay
SECAM till the colour transients on the colour bar of the pattern become as
sharper and colours between transients do not mix with each other as possible.
Note:
If the SAW filter is one of the G1965M, K2958M, K2962M, G3957M, K6256K or
K6259K, there is constant group delay distortion, so for an equal delay of the
luminance and chrominance signal the delay must be set at a value of
160nS. This means the adjustment must be
set to the maximum value.
Y-Delay
NTSC
Enter
an NTSC colour and black-white bar test pattern via RF. Adjust Y-Delay NTSC
till the colour transients on the colour bar of the pattern become as sharper
and colours between transients do not mix with each other as possible.
Note:
If the SAW filter is M1963M, there is constant group delay distortion, so for
an equal delay of the luminance and chrominance signal the delay must be set at
a value of 160nS. This means the adjustment must be set to the maximum value.
Y-Delay
Other
In
case of other colour systems, enter this system with colour and black-white bar
test pattern via RF. Adjust Y-Delay Other till the colour transients on the
colour bar of the pattern become as sharper and colours between transients do
not mix with each other as possible. Normally for an equal delay of the
luminance and chrominance signal the delay must be set at a value of
160nS. This means the adjustment must be
set to the maximum value.
VERTICAL
ZOOM ADJUSTMENT (only for 110 picture tubes):
Enter
a PAL B/G circle test pattern via RF. Change vertical zoom till you see the
upper and lower limit of the circle as close to the upper and lower limit of
the picture tube as possible.
VERTICAL
SCROLL ADJUSTMENT (only for 110 picture tubes):
Enter
a PAL B/G circle test pattern via RF. Change vertical scroll till you see the
circle exactly in the middle of the screen.
HORIZONTAL
SHIFT ADJUSTMENT:
Enter
a RED PURITY test pattern via RF.Change horizontal shift till the picture is
horizontally centred. Check whether this adjustment is correct after completing
Service Mode Adjustment.
VERTICAL
SLOPE ADJUSTMENT:
Enter
a CROSS-HATCH B/G test pattern via RF. Change vertical slope till the size of
squares on both the upper and lower part of test pattern become equal to the
squares laying on the vertical centre of the test pattern. Check and readjust
VERTICAL SLOPE item if the adjustment becomes improper after some other
geometric adjustments are done.
VERTICAL
AMPLITUDE ADJUSTMENT:
Enter
a PAL B/G test pattern via RF. Change vertical slope till horizontal black
lines on both the upper and lower part of the test pattern become very close to
the upper and lower horizontal sides of picture tube and nearly about to
disappear. Check and readjust VERTICAL AMPLITUDE item if the adjustment becomes
improper after some other geometric adjustments are done.
S-CORRECTION ADJUSTMENT:
Enter
a PAL B/G circle test pattern via RF. Change S-correction till the middle part
of the circle is as round as possible.
VERTICAL
SHIFT ADJUSTMENT:
Enter
a PAL B/G test pattern via RF. Change Vertical Shift till the test pattern is
vertically centred, i.e. horizontal line at the centre pattern is in equal
distance both to upper and lower side of the picture tube. Check and readjust
Vertical Shift item if the adjustment becomes improper after some other
geometric adjustments are done.
EW
WIDTH ADJUSTMENT (only for 110 picture tubes):
Enter
a PAL B/G test pattern via RF. Change EW Width till the vertical black and
white bars on both left and right side of the pattern exactly disappear.
EW
PARABOLA WIDTH ADJUSTMENT (only for 110ł picture tubes):
Enter
a PAL B/G test pattern via RF. Change EW Parabola Width till vertical lines
close to the both sides of the picture frame become parallel to vertical sides
of picture tube. Check and readjust EW Parabola Width item if the adjustment
becomes improper after some other geometric adjustments are done.
EW
CORNER PARABOLA ADJUSTMENT (only for 110ł picture tubes):
Enter
a PAL B/G test pattern via RF. Change EW Corner Parabola till vertical lines at
the corners of both sides of picture frame become vertical and parallel to
vertical corner sides of picture tube. Check and readjust EW Corner Parabola
item if the adjustment becomes improper after some other geometric adjustments
are done.
EW
TRAPEZIUM ADJUSTMENT (only for 110 picture tubes):
Enter
a PAL B/G test pattern via RF. Change EW Trapezium till vertical lines,
especially lines at the sides of the picture frame became parallel to the both
sides of picture tube as close as possible. Check and readjust EW Trapezium
item if the adjustment becomes improper after some other geometric adjustments
are done.
16:9
HORIZONTAL SHIFT ADJUSTMENT:
Enter
a RED PURITY test pattern via RF.Change horizontal shift till the picture is
horizontally centred. Check whether this adjustment is correct after completing
Service Mode Adjustment.
16:9
VERTICAL SLOPE ADJUSTMENT:
Enter
a CROSS-HATCH B/G test pattern via RF. Change vertical slope till the size of
squares on both the upper and lower part of test pattern become equal to the
squares laying on the vertical centre of the test pattern. Check and readjust
VERTICAL SLOPE item if the adjustment becomes improper after some other
geometric adjustments are done.
16:9
S-CORRECTION ADJUSTMENT:
Enter
a PAL B/G circle test pattern via RF. Change S-correction till the middle part
of the circle is as round as possible.
16:9
VERTICAL SHIFT ADJUSTMENT:
Enter
a PAL B/G test pattern via RF. Change Vertical Shift till the test pattern is
vertically centred, i.e. horizontal line at the centre pattern is in equal
distance both to upper and lower side of the picture tube. Check and readjust
Vertical Shift item if the adjustment becomes improper after some other
geometric adjustments are done.
16:9
EW WIDTH ADJUSTMENT (only for 110 picture tubes):
Enter
a PAL B/G test pattern via RF. Change EW Width till the vertical black and
white bars on both left and right side of the pattern exactly disappear.
EW
PARABOLA WIDTH ADJUSTMENT (only for 110 picture tubes):
Enter
a PAL B/G test pattern via RF. Change EW Parabola Width till vertical lines
close to the both sides of the picture frame become parallel to vertical sides
of picture tube. Check and readjust EW Parabola Width item if the adjustment
becomes improper after some other geometric adjustments are done.
16:9
EW CORNER PARABOLA ADJUSTMENT (only for 110 picture tubes):
Enter
a PAL B/G test pattern via RF. Change EW Corner Parabola till vertical lines at
the corners of both sides of picture frame become vertical and parallel to
vertical corner sides of picture tube. Check and readjust EW Corner Parabola
item if the adjustment becomes improper after some other geometric adjustments
are done.
16:9
EW TRAPEZIUM ADJUSTMENT (only for 110 picture tubes):
Enter
a PAL B/G test pattern via RF. Change EW Trapezium till vertical lines, especially
lines at the sides of the picture frame became parallel to the both sides of
picture tube as close as possible. Check and readjust EW Trapezium item if the
adjustment becomes improper after some other geometric adjustments are done.
