cxa1812q Sony Electronics, cxa1812q Datasheet - Page 17

• Manufacturer Part Number: cxa1812q
• Description: S-terminal Compatible Video I/o
• Manufacturer: Sony Electronics

The Y signal input to Pin 13 (YIN) is clamped by the sync tip and is then branched to the Y output system and
the VFY output system. The signal sent to the Y output system passes through the 75
and is then output from Pin 31 (YOUT).
Either the C signal input from Pin 7 (CIN) or the C signal for EE output that was branched from the C input
system is selected by the control signal input to Pin 6 (SEL2). After the signal is muted to the chroma center
level by the control signal input to Pin 4 (CMUTE), the signal is branched to the VFC output system and is also
passed through the 75
output from Pin 3 (COUT2) for composite video signal generation. The role of Pin 3 is explained in more detail
later.
When Pin 12 (P.SAVE) is set high, it is power saving mode. At this time, the Y and C 75
functioning and the outputs go to high impedance.
The Y signals input to Pins 13 and 11 (EVFYIN) are clamped by the respective sync tips, and one of the
signals is selected by the control signal input to Pin 10 (SEL1). When the video signal required for the
viewfinder is different from the signal input to Pin 13, the necessary signal is input from Pin 11. Titles are
inserted by the control signals input to Pins 22 (VOB1) and 20 (VOW1). Just as in the video input system,
regarding the title insertion levels, the white level is approximately 75IRE and the black level is approximately
10IRE. Either this Y signal or the post-Y/C MIX composite video signal is selected by the control signal input
to Pin 28 (Y/VSEL), and then the signal passes through the 12 dB amplifier and is output from Pin 19
(EVFY/VOUT). When Pin 28 is high, the post-Y/C MIX composite video signal is selected. At the same time,
the 6 dB amplifier (for C output) stops functioning in order to reduce the amount of current consumption. At
this time, the output from Pin 21 (EVFCOUT) goes to high impedance.
The C signal for the viewfinder that was branched from the C output system is muted to the chroma center
level by the control signals input to Pins 22 and 20. This signal is input to the Y/C MIX circuit in order to
generate the composite video signal for the viewfinder; the signal is also passed through the 6 dB amplifier and
is output from Pin 21.
EVFYIN
CIN
YIN
• VF Video Output System
CMUTE
SEL2
11
13
4
7
6
From C input system (EE)
CLAMP
CLAMP
driver (gain=12 dB), after which it is output from Pin 5 (COUT). The signal is also
L
H
H
L
To Y output system
SEL1
10
MUTE 3
VOB1 VOW1
22
DDS 2
—17—
20
MUTE 2
To C output system
L
H
Y/VSEL
28
12dB
6dB
driver (gain=12 dB)
To VF block
19
21
drivers cease
EVFY/VOUT
EVFCOUT
CXA1812Q