Digital Signal Path - Mitsubishi Electric WS-48513 Troubleshooting Manual

Digital Signal Path

The basic Digital Signal path was shown in Figure 5-2.
Figure 5-4 shows the Digital Path in more detail. Digi-
tal signal sources are the DTV/AQM Tuner, 1394 In-
puts and the front panel Card Reader. There are two
1394 inputs at the rear of the DM module. A third 1394
input is on the front of the Card Reader. The Card Reader
serves as a feed through for the 1394 signals and does
not process these signals at all.
The I.F. signal from the DTV/QAM Tuner is directed to
PCB-DEMODULATOR. The I.F. signal passes
through two SAW filters, and two I.F. amp ICs,
SF5200, IC5252, SF5201 and IC5253, in that order.
The (+) and (-) I.F. signals from IC5253 are directed to
pin 69 and 68 of the Demodulator, IC52A0. The out-
put of the Demodulator is the Transport data stream
used to modulate the carrier at the station.
The Transport Data Stream (TODATA) is directed to
the Digital Module. The signal is processed by the cir-
cuitry in the DM, and results in analog RGB signals out-
put at pins 8, 4, and 6 of the VA connector.
Signals from the 1394 inputs are processed in the DM
Digital Signal Processing circuitry and are output as ana-
log RGB signals at VA connector.
Signals from the Card Reader are send to the DM over
a USB cable. The DM also processes these signals
and outputs the resulting analog RGB signals.
5-5