Philips 32PFL5604H/12 Service Manual page 46

EN 46 7. Q543.3E LA
7.7 Back-End - On-board Timing Controller
(TCON)
In this platform, the Timing Controller (TCON) does not come
together with the LCD panel, but is integrated into the SSB. The
following figure shows the generic block diagram.
Generic Timing Controller Block
I2C-SET
PNX8543
LVDS Output
+12Vdisp
Figure 7-13 Block diagram Timing Controller
A Timing Controller is a key element in the "make-up" of an
LCD module. It forms the control centre, where it routes and re-
formats the data to column drivers on the LCD module.
Until now, the TCON was usually integrated into the LCD panel
and implemented through the use of ASIC devices, which
makes it impossible to re-use the TCON in other LCD panel
designs. Along with TCONs, discrete LVDS devices, using the
LVDS protocol, were also required for interface and control of
the LCD module.
A "new generation" of (programmable) Timing Controllers has
been designed which can be used on multiple LCD panel
designs. They can support non-standard resolutions and
different LCD panel configurations from various LCD
manufacturers. These TCON offer higher levels of integration
and, in addition, a new high-speed low voltage differential
interface protocol between the TCON and Column Driver (CD)
has been developed, called Reduced Swing Different
Signalling (RSDS). The use of this protocol offers higher data
transfer rates.
In this chassis, such a "new generation" programmable TCON
has been implemented. The inputs to the TCON are the LVDS
output from the PNX8543 and the +12V display supply. The
TCON converts the LVDS signal into the required format:
• mini-LVDS signals for LGD LCD panels, or
• RSDS signals for Sharp LCD panels.
The LCD bias supply block generates the bias voltages VG
and VG , as well as the source voltage V
L
V for the LCD panel.
logic
The output signal of the VCOM Calibrator, V
voltage for Liquid Crystal Driving. This can be aligned to
minimize flicker on the display resulting from non-symmetrical
voltages that aligns the liquid crystals. Both Sharp and LGD
TCONs use a programmable VCOM Calibrator IC for V
adjustment. The adjusted VCOM data will be stored inside on-
chip memory and will be automatically recalled during each
power-up. For instructions on how to program the TCON and
set the correct value of the reference voltage, refer to ComPair.
It should be noted that in this platform the use of the TCON is
display-related: the use of a different branded LCD panel
2010-Jun-29
Circuit Descriptions
For programming
Connector
purposes
VCOM Calibrator Vcom
LCD Timing
Mini-LVDS
Controller
or RSDS
FFC Cables
to Display
VGH
LCD Bias VGL
Supply
Vsource
Vlogic
Gamma
Gamma-Voltage
Voltage
Circuitry
Levels
18440_212_090227.eps
and logic voltage
source
, is a reference
com
com
automatically implies the use of another TCON, thus another
SSB.
For trouble shooting, below find an overview of the DC voltages
used on the TCON circuitry.
Table 7-2 DC voltages
Signal
VG
H
VG
L
V
CC
V
CC
V
ref
V
DD
MV
LS
7.8 Common Interface CI+
Together with this platform, an extension to the Common
Interface (CI) Conditional Access system is added, called CI+.
090227
CI+ or Common Interface Plus is a specification that extends
the Common Interface (DVB-CI) as described in the digital
broadcasting standard DVB.
The weakness of the conventional CI module used in a
Conditional Access system was the absence of a Copy
Protection mechanism, as decrypted content could be sent
over the PCMCIA interface unscrambled. With the CI+
extension, a form of copy protection is established between the
Conditional Access Module (CAM) and the Integrated Digital
Television (IDTV). The security mechanisms in CI+ are
derived/copied from POD (with the exception of Out Of Band
(OOB) used in US CA systems). For more information about
conventional CA systems using a CI module, refer to the
BJ3.0E L/PA or BL2.xU Service Manual.
The CI+ standard is downwards compatible with the existing CI
standard.
The following figure shows the implementation of the CI+
Conditional Access system in the TV543 platform.
H
Display Destination
LG Sharp
+25 V +35 V to gate drivers (high voltage)
-6 V -6 V to gate drivers (low voltage)
+3.3 V +3.3 V timing controller IC supply
voltage
+1.2 V +1.5 V timing controller IC supply
voltage
+16 V +15.2 V gamma reference voltage
+16 V +15.6 V source driver supply
- +9 V MPD IC supply voltage