Hitachi 61HDX98B Manual page 10

BLOCK DIAGRAM EXPLANATION A/V SELECTOR
C. VIDEO (MAIN) and R/L (AUDIO MAIN):
NTSC Video and NTSC Audio is routed from the
DM-1 Block diagram. They are shown in the Block
Diagram as one line, but they are separate signals.
Anytime a signal is routed from the DM-1 or going to
the DM-1 module, they must be sent through a DM-1
I/F block. This block reduces the noise by a noise can-
cellation process. This process uses the output of a
comparator and routes the output back to the negative
input to subtract the noise. It also level shifts the signal
to make it useable by the circuit to which it is routed.
DM-1 I/F BA4558:
This is the noise cancellation and level shift block.
AUDIO/VIDEO SELECTOR TA8851BN:
This is the selector IC. Dependant upon the customer's
viewing preference, the DM-1 will communicate via
I2C bus communications and select the NTSC signal
which is sent to the demodulator. The demodulator
prepares the NTSC signal for the DM-1 module.
This IC selects the following inputs;
Main tuner
Video One, Two or Three
S-In One, Two or Three
PinP Video and Audio outputs. This can be any of the
input provided above except the PinP has it's own
tuner.
Note: PinP isn't available when the customer has se-
lected Direct TV or ATSC as it's source. This is be-
cause, as will be shown later, the PinP Video is super
exposed upon the NTSC video only.
Any video source selected for the Main picture will be
routed to the 3D Y/C module.
Note: There are NO Component inputs on this set.
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