Circuit Descriptions - Philips L04LAA Service Manual

Circuit Descriptions, List of Abbreviations, and IC Data Sheets
9. Circuit Descriptions, List of Abbreviations, and IC Data Sheets
Index of this chapter:
1. Introduction
2. Power Supply
3. Deflection
4. Control
5. Tuner and IF
6. Source Selection
7. Audio
8. Video
9. Abbreviations
10. IC Data Sheets
Notes:
•
Only new circuits compared to the L01.1 chassis are
described in this chapter. For the other circuit descriptions,
see the manual of the L01.1 chassis.
•
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 "L04" chassis is a global TV chassis for the model year
2004 and is used for TV sets with large screen sizes (from 21
to 36 inch), in Super Flat and Real Flat executions (both in 4:3
and 16:9 variants).
There are three types of CRT namely the 100 degrees, 110
degrees and Wide Screen CRT.
•
The 100 deg. 4:3 CRT is raster-correction-free and does
not need East/West Correction (except when used in AP
regions), therefore the corrections needed are Horizontal
Shift, Vertical Slope, Vertical Amplitude, Vertical S-
Correction, Vertical Shift, and Vertical Zoom for geometry
corrections.
•
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.
•
The Wide Screen TV sets have all the correction of the
110 deg. 4:3 CRTs and also have additional picture format
like the 4:3 format, 16:9, 14:9, 16:9 zoom, subtitle zoom,
and the Super-Wide picture format.
In comparison to its predecessor (the L01.1), this chassis is
has the following (new) features:
•
Audio: The sound processor is part of the UOC processor
(called "Hercules").
•
Video: Enhanced video features, video drivers, and Active
Control.
•
Control: Comparable to L01.1 (e.g. Dual clock, I/O
mapping, I/O switching).
•
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 (called
"family board"), a Picture Tube panel, a Side I/O panel, and a
Top Control 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:
L04L AA
•
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
(depends on region).
•
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.
The on-screen graphics and closed caption decoding are done
within the microprocessor where they are added to the main
signal.
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.
9.2
Power Supply
9.2.1
Block Diagram
FILTER& MH coil
WITCH RECTIFIER
Degaussing upply (V_DG)
RELAY
Derived from =Vaudio
DEGAU
Figure 9-1 Block diagram power supply
Stdby_con signal
The Hercules generates this signal. This line is logic "low" (0 V)
under normal operation and in semi-Standby of the TV, and is
"high" (3.3 V) during Standby.
Power_down signal
The AUX SMPS generates this signal. It is logic "high" (3 .3 V)
under normal operation of the TV and goes "low" (0 V) when the
AC power (or Mains) input voltage supply goes below 70 V_ac.
B (Hercules port)
This port is used to switch the AUX SMPS output V_aux "On/
Off". This is required for DVD and iDTV (for future extensions).
9. EN 81
Vbatt (to deflection & DVD interface board)
-Vaudio
+Vaudio
MAIN MP
+6V (from AUX MP for tdby feedback)
tdby_Con (from HERCULE )
Power_Down (to HERCULE )
+3V (to derive HERCULE supply 1.8V)
+6V (to derive HERCULE & TUNER)
AUX MP
supply +5V & +3.3V)
Vaux (for IDTV)
B (connected to HERCULE port B to
switch ON/OFF Vaux)
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