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Multimedia ICs
Video signal switcher, 1 × 3-channel
with clamped-input
BA7653AF
The BA7653AF is a video-signal switching IC that contains a three-channel clamped-input multiplexer. The inputs
are sync-tip clamped (synchronous edge of the video input signals are aligned to the same voltage), and as the input
impedance is extremely large, it is possible to use a small value for the clamp capacitor (the recommended capacitor
is 0.01µF (FZ) ceramic).
•
Applications
Video cassette recorders, television and camcorders
•
Features
1) Small clamp capacitors can be used (ceramic,
3000pF (Min.), 0.01µF (FS) (recommended)).
2) Low supply voltage operation possible. Supply voltage range is 3.7V to 7.7V.
3) Superimposition used for fast switching speed with
low switching noise (70nsec. Typ.).
4) Low power consumption (when V
CC = 5V, 25mW
Typ.).
5) Wide dynamic range (3.1V
P-P Typ. for VCC = 5V).
6) Excellent frequency characteristics (10MHz, 0dB
Typ.).
7) Low interchannel crosstalk ( – 70dB Typ.).
8) Voltage can be applied to the control pins even
when V
CC is not applied.
•
Absolute maximum ratings (Ta = 25°C)
Parameter
Symbol Limits Unit
V
CC 9V
mW
Topr °C
Tstg °C
500
∗
Pd
– 25 ~ + 75
– 55 ~ + 125
Applied voltage
Power dissipation
Operating temperature
Storage temperature
∗
When mounted on a 50mm × 50mm board, reduced by 5mW for each increase in Ta of 1°C over 25°C.
•
Recommended operating conditions (Ta = 25°C)
Parameter Symbol Limits Unit
V
CC V4.0 ~ 7.0
Power supply voltage
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Multimedia ICs BA7653AF
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Electrical characteristics (unless otherwise noted, Ta = 25°C and VCC = 5.0V)
Parameter Symbol Unit ConditionsMin. Typ. Max.
V
CC 3.7 — —
—
7.7 V
I
CC 2.7 5.0 8.2 mA
V
om 2.6 3.1 — VP-P
GV – 0.5 0 dB
C
ta – 70 dB
G
f – 3.0 0 dB
V
TH L — — 1.0
V
V
TH H 2.5 — —
45
× 20 (V)
V
CC – VF
VTH =
——
f = 1kHz, THD = 1.0%
f = 1MHz, V
IN = 1.0VP-P
f = 4.43MHz, VIN = 1.0VP-P
f = 10MHz / 1MHz, VIN = 1.0VP-P
VCC – CTL Threshold Level
0.5
1.0
Operating voltage
Supply current
Maximum output level
Voltage gain
Interchannel crosstalk
Frequency characteristic
CTL switching voltage
•
Guaranteed design parameters (unless otherwise noted, Ta = 25°C and VCC = 5.0V)
Parameter Symbol Unit ConditionsMin.
DG — 0 0.5 %
DP — 0.5 1.0 deg
Typ. Max.
Differential gain
Differential phase
V
IN = 1.0VP-P, standard staircase signal
V
IN = 1.0VP-P, standard staircase signal
•
Pin descriptions
1 IN1
2 CTLa
3 IN2
4 CTLb
5 IN3
6V
CC
7OUT
8GND
Pin No. Pin name
Input 1
Control input a
Input 2
Control input b
Input 3
Supply voltage
Output
GND
Function
•
Control pin truth table
CTLa CTLb OUT
L L IN1
H L IN2
L H IN3
H H IN3
•
Block diagram
1
2
3
4
8
7
6
5
IN1
CTLa
IN2
CTLb
GND
OUT
IN3
Logic
VCC
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Multimedia ICs BA7653AF
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Input / output circuits
1 IN 1 1.65V
2 CTLa — —
3 IN 2 1.65V
4 CTLb — —
50µA
100
IN1
V
CC
VCC
VCC
VCC
2.3V
1.9V
50k
CTLa
50µA
100
2.3V
1.9V
50k
CTLb
50µA
Pin No.
IN2
Pin name
DC voltage
(V
CC = 5V)
Input / output
impedance
Equivalent circuit
10M
Ω
or more
10MΩ
or more
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Multimedia ICs BA7653AF
50µA
100
V
CC
VCC
VCC
VCC
OUT
1mA
GND
5 IN 3 1.65V
6VCC 5.0V —
7 OUT 0.95V
8 GND 0V —
Pin No.
IN3
Pin name
DC voltage
(V
CC = 5V)
Input / output
impedance
Equivalent circuit
10M
Ω
or more
26Ω
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Multimedia ICs BA7653AF
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Application examples
1
2
3
4
8
7
6
5
IN1
CTLa
IN2
CTLb
GND
OUT
V
CC
IN3
Logic
Logic
Logic
VCC
C. Video In
C. Video In
C. Video In
C. Video Out
0.01µ
0.01µ
0.01µ
47µ 0.1µ
+
When superimposition is used
1
2
3
4
8
7
6
5
IN1
CTLa
IN2
CTLb
GND
OUT
IN3
Logic
Logic
Logic
47µ 0.1µ
VCC
VCC
DC1.7V or more
DC1.7V or more
C. Video or DC Out
C. Video In
0.01µ
Fig. 1
+
•
Operation notes
(1) To ensure stable clamp operation, the output
impedance of the previous stage connected to the
inputs should be 1kΩ or lower.
(2) If large input clamp capacitors are used, the time
constant of the circuit will mean that some time will be
required until stable operation after power is applied.
The value for the input clamp capacitors is 0.1µF Max.
(0.01µF (FZ) ceramic capacitor recommended).
(3) The BA7653AF is a three-channel multiplexer, but
two-channel operation is also possible. In this case, if
the unused input is left open it will oscillate, but this will
not effect the other inputs and cause problems. If this is
a concern, ground the unused input via a capacitor, or
connect it directly to V
CC.
(4) If control inputs are left open they will be unstable,
set to H or L.
(5) When using superimposition, the DC voltage directly applied to the inputs should be at least 1.7V.
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Multimedia ICs BA7653AF
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External dimensions (Units: mm)
SOP8
0.4 ± 0.11.27
0.15
0.3Min.
0.15 ± 0.1
0.11
6.2 ± 0.3
4.4 ± 0.2
5.0 ± 0.2
85
41
1.5 ± 0.1
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