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EN 168
9.
DVDR980-985 /0X1
switching. The output of the pre-selector switches is connected
to the STV 6410, and then the signal is routed via the 75-Ohm
driver BA 7623 to the Rear Out S-Video socket.
Also the video quality will be S-Video, the digital board supplies
also CVBS and Y/UV to the corresponding sockets.
Y/UV Signals:
The Y/UV In signal is routed direct to the digital board, there is
no Y/UV IN -> Y/UV Out loop through in low power standby. As
the digital board supplies only RGB signals, a RGB Y/UV
matrix is used. This matrix consists of the operational amplifier
TSH95 which generates the U and V signals according the
formulas: 2U=B-0,338R-0,661G, 2V=R-0,838G-0,161B. Then
the signals are routed to the UV Output sockets via the 75-Ohm
driver BA 7623. The corresponding Y signal is coming from the
digital board via the STV 6410. The 75 Ohm Y socket is driven
by the 75-Ohm driver BA 7623 and finally connected to the of
the Y/UV Output.
Detection of Status-Information
WSS on Y/C-Plug:
•
Picture-Ratio-Information (16:9 or 4:3) on SVHS-
connections is coded via the average DC-level of the
Chroma-signal-line, detection is realised by using an
analogue-input-port of the CC-C.
•
ADC- value lower or equal 40h ( 4:3-picture-ratio delivered
•
ADC-value greater 40h ( 16:9-picture-ratio available on
plug
•
Y/C-Rear is determined via Port40/AIN3 (Pin14) of CC
(WSRI-line) and Port41/AIN4 (Pin15) is used for Y/C-Front
(WSFI-line).
Generation of Status-Information
WSS on Y/C-Plug:
The appropriate DC-level on Chroma-signal-line for Y/C-Rear-
Out is produced via Port57 (Pin10) of the CC-C (WSRO-line).
•
4:3 - Picture-ratio supported on Y/C-Plug: Port57 set to 0
•
16:9 - Picture-ratio supported on Y/C-Plug: Port57 set to 1
9.4.9
Audio routing Analogue board (Europe / Nafta)
General Description:
The Audio- I/O switching is realised by the STV6410 I/O switch.
2
By I
C Bus (SDA-0/SCL-0) it is possible to control all the Audio
in- and outputs (for detailed Information we refer to the
STV6410 routing overview).
Analog audio coming from DV-Board and second rear Cinch
input is routed via MSP3415 to the STV 6410. After selecting
the audio source via STV 6410, the signal must be transformed
into the digital domain. For this, the UDA 1360TS (ADC) is
responsible. An input-voltage of up to 2Vrms can be handled
from the IC´s. For further processing, the UDA 1360TS (ADC)
2
delivers the data-in I
S format to the digital-board. After a
certain delay the (processed) data come back from the digital
board to the UDA 1328 (DAC). The UDA 1328 (DAC)
2
transforms the I
S data back into the analog domain and feeds
the signals direct to the MC33078 (OPV). From the MC33078
(OPV) the signals are delivered back to the STV 6410 and also
direct to the 2nd rear out Cinch. The other outputs (Scart,
Cinch) are supported by the STV 6410.
Detailed Description STV 6410:
2
The STV 6410 is an I
C bus controlled audio and video switch
matrix, which is able to handle audio input signals up to 2 Vrms.
The used outputs are equipped with internal level adjustment
possibility. Low distortion and very good channel separation is
a typical peculiarity of this IC. The output resistance is very low
and the frequency bandwidth is up to 50 kHz.
Circuit-, IC Descriptions and List of Abbreviations
Detailed Description UDA 1360:
The UDA 1360TS is a stereo Analog-to-Digital Converter
employing bitstream conversion techniques.
2
The UDA supports the I
S-bus data format and the MSB-
justified data format with word lengths of up to 20 bits. The IC
supports also 2Vrms input signals and is designed for 3V3
supply voltage.
The device is able to handle system clocks of 256fs and 384fs.
Typical THD+N at 0dB is -85dB and a S/N performance up to
97dB is possible.
Detailed Description UDA 1328:
The UDA1328 is a 6 channel DAC employing bitstream
conversion techniques, which can be used either in L3
microcontroller mode or in static pin mode.
2
The UDA 1328 supports the I
S-bus data format with word
lengths of up to 24 bits.
Digital sound features can be controlled with the L3 interface.
System clock can be set to 256fs or 384fs.
The Device also provides 2 high quality differential outputs.
Typical THD+N at 0dB is -95dB and a S/N of up to 106dB is
possible.
Supply voltage is 3V3.
Detailed Description MC 33078:
The MC33078 is a dual operational amplifier for audio
applications.
It offers low voltage noise (4,5nV/√Hz) and high frequency
performances (15MHz Gain Bandwidth product, 7V/s slew
rate).
In addition the MC33078 has a very low distortion (0,002%).
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