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Plasma TV Service Manual 05/01/2006
help, Audio amplifier and mute time constant,
I²C
-bus transceivers and MAD (module address), Internal
voltage stabilizer.
4. MULTI STANDARD SOUND PROCESSOR
The MSP34x0G family of single-chip Multistandard Sound Processors covers the sound processing of
all analogue TV-Standards worldwide, as well as the NICAM digital sound standards. The full TV sound
processing, starting with analogue sound IF signal-in, down to processed analogue AF-out, is
performed on a single chip.
These TV sound processing ICs include versions for processing the multichannel television sound
(MTS) signal conforming to the standard recommended by the Broadcast Television Systems
Committee (BTSC). The DBX noise reduction, or alternatively, Micronas Noise Reduction (MNR) is
performed alignment free. Other processed standards are the Japanese FM-FM multiplex standard
(EIA-J) and the FM Stereo Radio standard.
Current ICs have to perform adjustment procedures in order to achieve good stereo separation for
BTSC and EIA-J. The MSP 34x1G has optimum stereo performance without any adjustments.
5. VIDEO SWITCH TEA6415
In case of three or more external sources are used, the video switch IC TEA6415 is used. The main
function of this device is to switch 8 video-input sources on the 6 outputs.
Each output can be switched on only one of each input. On each input an alignment of the lowest level
of the signal is made (bottom of sync. top for CVBS or black level for RGB signals).
Each nominal gain between any input and output is 6.5dB.For D2MAC or Chroma signal the alignment
is switched off by forcing, with an external resistor bridge, 5VDC on the input. Each input can be used
as a normal input or as a MAC or Chroma input (with external Resistor Bridge). All the switching
possibilities are changed through the BUS. Driving 75ohm load needs an external resistor. It is possible
to have the same input connected to several outputs.
6. AUDIO AMPLIFIER STAGE WITH TDA8928
The TDA8928 is a switching power stage for a high efficiency class-D audio power amplifier system.
With this power stage a compact 2 x 10 W self oscillating digital amplifier system can be built, operating
with high efficiency and very low dissipation. No heatsink is required. The system operates over a wide
supply voltage range from +-7.5 V up to +-30 V and consumes a very low quiescent current.