THOMSON MCR61TF30, Service Manual

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SERVICE MANUAL
OM8839PS (N301)
I
2
C-bus Controlled PAL/NTSC/SECAM TV Processors
1. Features
The following features are available in all IC’s:
·Multi-standard vision IF circuit with an
alignment-free PLL demodulator without external
components
·Alignment-free multi-standard FM sound
demodulator (4.5 MHz to 6.5 MHz)
·Audio switch
·Flexible source selection with CVBS switch and
Y(CVBS)/C input so that a comb filter can be
applied
·Integrated chrominance trap circuit
·Integrated luminance delay line
·Asymmetrical peaking in the luminance channel
with a (defeatable) noise coring function
·Black stretching of non-standard CVBS or lumina-
nce signals
·Integrated chroma band-pass filter with switchable
centre frequency
·Dynamic skin tone control circuit
·Blue stretch circuit which offsets colours near
white towards blue
·RGB control circuit with “Continuous Cathode
Calibration” and white point adjustment
·Possibility to insert a“blue back” option when no
video signal is available
·Horizontal synchronization with two control loops
and alignment-free horizontal oscillator
·Vertical count-down circuit
·Vertical driver optimised for DC-coupled vertical
output stages
·I
2
C-bus control of various functions
2. General Description
The various versions of the TDA 884X/5X
series are I
2
C-bus controlled single chip TV
processors which are intended to be applied in
PAL, NTSC, PAL/NTSC and multi-standard
television receivers. The N2 version is pin and
application compatible with the N1 version,
however, a new feature has been added which
makes the N2 more attractive. The IF PLL
demodulator has been replaced by an
alignment-free IF PLL demodulator with
internal VCO (no tuned circuit required). The
setting of the various frequencies (33.4, 33.9,
38, 38.9, 45.75 and 58.75 MHz) can be made
via the I
2
C-bus.
Because of this difference the N2 version is
compatible with the N1, however, N1 devices
cannot be used in an optimised N2 application.
Functionally the IC series is split up in 3
categories, viz:
·Versions intended to be used in economy TV
receivers with all basic functions (envelope:
S-DIP 56 and QFP 64)
·Versions with additional features like E-W
geometry control, H-V zoom function and
YUV interface which are intended for TV
receivers with 110° picture tubes (envelope:
S-DIP 56)
·Versions which have in addition a second
RGB input with saturation control and a
second CVBS output (envelope: QFP 64)
The various type numbers are given in the
table below.
3. Survey of IC Types
Envelope S-DIP 56 QFP 64
TV receiver category Economy Mid/High end Economy Mid/High end
PAL only TDA 8840 TDA 8840H
PAL/NTS TDA 8841 TDA 8843 TDA 8841H
PAL/SECAM/NTSC TDA 8842 TDA 8844 TDA 8842H TDA 8854H
NTSC only TDA 8846/46A TDA 8847 TDA 8857H
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