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Circuit Descriptions, List of Abbreviations, and IC Data Sheets
period and delivers the energy to C2465 during the Line
scanning period. Throughout the Frame period, the charging
and discharging of C2456 works alternatively. However, at the
first half of the Frame scanning, TS7451 is "on" and consumes
all the charge from C2456. When entering 2nd half Frame
period, TS7451 is "off", so C2456 will gradually charge up to the
required flyback supply.
C2463, R3464 and D6457 are for boosting the base voltage of
TS7451 during the flyback period and the 1st half Frame period
as well. C2463 is charged by D6457 during the 2nd half
scanning. R3467 and R3468 are for oscillation damping.
The V_guard protection is to protect the Frame stage if a fault
condition happens. The V_guard will sense the pulse with
voltage > 3.8 V and period < 900 us. Any signal out of this
range will be considered as fault, and the chassis will be shut
down.
9.3.8
Tilt and Rotation
The rotation control signal is a PWM output from the UOC. It is
filtered by R3252, R3246, R3259 and C2259. The DC voltage
after filtering at C2259 will be amplified by R3245 (Main Board)
and R3390 (CRT panel).
The output stage functions similarly as in L01.1/M8 with
rotation IC TDA8941P. TS7331/TS7382 and TS7332/TS7381
will function alternatively corresponding to the rotation setting.
9.3.9
CRT panel
The RGB amplifier stage is exactly the same as in L01.1/M8.
However, the RGB amplifier IC has been changed to
TDA6107AJF or TDA6108AJF. The "A" indication is with gain
of "80" rather than "50" in L01.1/M8. The diode D6332 used in
the former chassis, to solve the bright screen during start up, is
not required because this IC has the error correction
implemented.
Scavem
In certain versions, the Scavem feature is used to enhance the
sharpness of the picture. The RGB signals are first
differentiated and subsequently amplified before feeding to an
auxiliary coil known as the SVM coil. The current, flowing
through the SVM coil during the picture intensity transients,
modulates the deflection field and thus the scan velocity.
During the first half of the intensity increase, the scan velocity
is increased (thus decreasing the current density by spreading
it on a wider area). During the second half of the intensity
increase, the scan velocity is decreased (increasing the current
density by concentrating it on a smaller area). The increasing
current density transition is sharpened. A decreasing current
density transition is processed in a similar way and is also
sharpened.
In this chassis the SCAVEM signal is different from its
predecessor because the Hercules generates the differential
SCAVEM signal inside the IC.
The supply of the SCAVEM is taken from V_bat through a 1k5
/ 5 W resistor. Compared with the L01.1/M8, this has the
advantage of getting better performance for the pattern with
tremendous SCAVEM current (like V_sweep). In this former
chassis, because the supply was taken from the 200 V through
a 8k2 / 5 W resistor, the supply dropped significantly during a
large SCAVEM current. In this chassis, the drop due to the
pattern will be less because of the lower supply voltage
impedance.
In the Main Board, 1st stage amplification is taken care by 7208
with the pull up resistors (3361, 3387) located in the CRT panel.
TS7361 and TS7362 is the current buffer delivering the current
to the output stage. The diode D6361 is to lightly bias these
transistors, to get rid of the zero crossover of the stage.
L04E AA
After that, the signal is ac-coupled to TS7363 and TS7364
where the emitter resistors (R3364 and R3370) will determine
the final SCAVEM current. TS7363 and TS7364 are biased by
R3363, R3366, R3367 and R3368.
C2387, R3388, R3389, R3365, R3369, C2384, and C2385 are
used for suppressing unwanted oscillations.
The function of TS7376 is to limit the SCAVEM current from
going too high. It basically senses the voltage after R3373 and
clamps the SCAVEM signal through D6367 and C2376.
9.4
Control
The Micro Controller is integrated with the Video Processor,
and is called the Hercules. For dynamic data storage, such as
SMART PICTURE and SMART SOUND settings, an external
NVM IC is being used.
Another feature includes an optional Teletext/Closed Caption
decoder with the possibility of different page storage depending
on the Hercules type number.
The Micro Controller ranges in ROM from 128 kB with no TXT-
decoder to 128 kB with a 10 page Teletext or with Closed
Caption.
9.4.1
Block Diagram
The block diagram of the Micro Controller application is shown
below.
Power Supply
STBY_CON
POWER GOOD
KEYBOARD/
PROTECTION
KEYBOARD/PROTECTION
CIRCUIT
VIDEO
INPUT
VOLUME/MUTE/TREBBLE /BASS/PANORAMA
ONO AUDIO PROC.
OUTPUT
AUDIO A P
LIGHT SENSOR
LED
ONITOR
IR
OUTPUT
LIGHT SENSOR
LED
IR
Figure 9-4 Micro Controller block diagram
9.4.2
Basic Specification
The Micro Controller operates at the following supply voltages:
•
+3.3 V_dc at pins 33, 125, and 19.
•
+1.8 V_dc at pins 126, 36, and 33.
•
I2C pull up supply: +3.3V_dc.
9.4.3
Pin Configuration and Functionality
The ports of the Micro Controller can be configured as follows:
•
A normal input port.
•
An input ADC port.
•
An output Open Drain port.
•
An output Push-Pull port.
•
An output PWM port.
•
Input/Output Port
The following table shows the ports used for the L04 control:
9.
EN 77
WRITE
PROTECT
NVM
ST24C16W6
ERCULES
Micro
IIC
Controller
Data
Lines
LTI\CTI
orizontal
Pulse
TUNER
DEFLECTION
E_14480_070.eps
120504
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