Philips L04A AB, Service Manual, Page: 73 / 90

Circuit Descriptions, List of Abbreviations, and IC Data Sheets EN 73 L04A AB 9.
9. Circuit Descriptions, List of Abbreviations, and IC Data Sheets
Index of this chapter:
9.1 Introduction
9.2 Power Supply
9.3 Deflection
9.4 Control
9.5 Tuner and IF
9.6 Source Select
9.6 Source Select
9.7 Video Processing
9.8 Audio Processing
9.9 Picture in Picture (PIP)
9.10 Abbreviation list
9.11 IC Data Sheets
Notes:
• Only new (not recently published) circuits are described in
this chapter. For the other circuit descriptions, see the
L04A AA Service Manual.
• Figures can deviate slightly from the actual situation, due
to different set executions.
• For a good understanding of the following circuit
descriptions, please use the diagrams in sections “Block
Diagrams, ...”, and/or “Electrical Diagrams”. Where
necessary, you will find a separate drawing for clarification.
9.1 Introduction
The "L04A AB" chassis is a 2fh TV chassis for the China market
only. For the year 2004 only two large screen sizes are
available (29 and 34inch) in Real Flat 4:3 execution.
The 110 deg. 4:3 CRT comes with East/West Correction. In
addition to the parameter mentioned above, it also needs the
Horizontal Parallelogram, Horizontal Bow, Horizontal Shift,
East/West Width, East/West Parabola, East/West Upper and
Lower Corners, and East/West Trapezium correction.
In comparison to L04A AA this is a 2fh chassis. For this a new
board is added for 2fh signal processing, the so-called ‘Trident
board’. Trident Board is design to handle the standard video
display source(1fH) of either CVBS or YPbPr and High
definition video display source of 1920/1080i in 2fH according
to China GB draft for digital tv display. The scan rate
conversion from 1fH to 2fH in interlace or progressive scanning
format is performed at the scaling part of SVP chip. The SVP
also perform NTSC/PAL/SECAM video decoding function, but
this is not used. Basically, 3 output display format has been
selected to match with our 31.25/31.50 KHz CRT deflection
system design. There are 1080i/50Hz,625i/100Hz and 480p/
60Hz.
Since the deflection part is newly designed it also will use more
power thus the power supply has been modified. this chassis is
has the following (new) features:
•
Video: Enhanced video features, video drivers, and Active
Control.
• Power Supply: Adapted to supply the Hercules IC, and to
enable 0.5 W Standby power dissipation. Also provisions
are made for future extensions like DVD and iDTV.
The standard architecture consists of a Main panel, the Trident
Module consisting of a ‘Interface’ panel and ‘Trident’ panel, a
CRT (Picture Tube) panel, a Side AV panel, and a Front
Interface panel. The Main panel consists primarily of
conventional components with some surface mounted devices
in the audio and video processing part.
The functions for video/audio processing, microprocessor (P),
and CC/Teletext (TXT) decoder are all combined in one IC
(TDA1200x, item 7200), the so-called third generation Ultimate
One Chip (UOC-III) or “Hercules”. This chip is mounted on the
“solder” side of the main panel, and has the following features:
•
Control, small signal, mono/stereo, and extensive Audio/
Video switching in one IC.
• Upgrade with digital sound & video processing.
• Alignment free IF, including SECAM-L/L1 and AM.
• FM sound 4.5/5.5/6.0/6.5, no traps/bandpass filters.
• Full multi-standard color decoder.
• One Xtal reference for all functions (microprocessor, RCP,
TXT/CC, RDS, color decoder, and stereo sound
processor).
The tuning system features 181 channels with on-screen
display. The main tuning system uses a tuner, a
microcomputer, and a memory IC mounted on the main panel.
The microcomputer communicates with the memory IC, the
customer keyboard, remote receiver, tuner, signal processor IC
and the audio output IC via the I2C bus. The memory IC retains
the settings for favorite stations, customer-preferred settings,
and service / factory data.
Figure 9-1 Block diagram Video
The UOC-III interfaces with the DPTV SVP a digital video
processor which converts the 1fh video signal into 2fh. (see
Block diagram video) and is placed on the Trident panel. This
architecture makes it necesarry that a TDA9332 which does
the 2fh video output processing. Also a OSD generator is
added the MTV030. These latter functions of the UOC are
therefore not used.
The chassis uses a Switching Mode Power Supply (SMPS) for
the main voltage source. The chassis has a 'hot' ground
reference on the primary side and a cold ground reference on
the secondary side of the power supply and the rest of the
chassis.
HOP
TDA9332
MTV030
UOC III
(HERCULES)
CVI CRT PANEL
(TDA6108)
OSD
GENERATOR
SVP
AD9883
SOG
YPbPr
(1080i)
SAW SAW
VIF SIF
CRT Panel
2 fH Deflection
Stage
FB
SDRAM
4x1MB
E_14770_044.eps
010904
Tu
n
e
r
AV1
/2
AV
O/P
SVHS
R
G
R G B BLK SVM
H V B R G
H V CLK
Y
B
H
EW
V+
V-
8V
EHT
BCL
Hfb
5V
IIC
CVBS
YUV
RESET
SOG
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