Televisions (Teletext-capable), captain systems, video cameras, personal computers
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Featuressuperimposition of video images (VIDEO IN)
1) Allows
and computer images (RGB IN).
2) During superimposition, the subcarrier locked onto
the video input burst signal RGB is modulated with
the RGB signals by the APC circuit, preventing
unnatural color disturbance due to switching.
3) Both the RGB and video input signals are pedestal-
clamped, maintaining a natural image even during
fluctuation in luminosity.
4) Using a half down pulse, the video signal can be
reduced by 5dB to darken the background and
make the superimposed RGB image easier to see.
5) Carrier leak is suppressible to less than 70mV
P-P
(V
OUT
= 2V
P-P
) without adjustment.
6) Can be adapted for analog RGB input.
7) Compact 24-pin SZIP package minimizes external
components.
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Block diagram
BA7230LS
VIDEO OUT
1
2
SYNC IN
Y IN
R-Y IN
3
+
+
4
B-Y IN
BURST LEVEL
ADJUSTMENT
V
B
5
6
V
C
V
A
7
MOD
MOD
8
9
VCXO
10
BFP IN
APC PHASE
11
ADJUSTMENT
AR
13
PD
12
PD
14
AG
AB
15
MATRIX
B-Y OUT
17
B-Y
GND
19
HD
PCP IN
21
22
HDP IN
20
VIDEO IN
16
Y OUT
R-Y
18
R-Y OUT
Y
S
P IN
23
V
CC
24
V
CC
1
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