Multimedia ICs
Video switch for CANAL-Plus decoder
BA7631 / BA7631F
The BA7631 and BA7631F are audio-switching ICs for decoders for scrambled pay channels used in France and
other countries. The ICs include a five-input multiplexer, a four-input multiplexer and a two-input multiplexer, and
allow decoder audio switching to be done with a single IC. When used in combination with the BA7630S common
logic control can be used for audio and video switching.
•
Applications recorders
Video cassette
•
Features
1) All the audio-switching functions required for SECAM
CANAL -plus decoder integrated onto one chip.
2) Inputs terminated with 65kΩ resistors.
3) Built-in output buffer.
4) Wide supply voltage range (4.5V to 13.0V).
5) Low total harmonic distortion (0.005% Typ.).
6) Wide dynamic range (3.6Vrms, V
CC
= 12V).
7) Same control logic as for the BA7630S can be used.
•
Absolute maximum ratings
Parameter
Applied voltage
Power dissipation
Operating temperature
Storage temperature
Symbol
V
CC
Pd
Topr
Tstg
Limits
13.5
1100
∗
(DIP)
500
∗
(SOP)
– 25 ~ + 70
– 55 ~ + 125
Unit
V
mV
°C
°C
∗
Reduced by 11mW (DIP) or 5mW (SOP) for each increase in Ta of 1°C over 25°C.
•
Recommended operating conditions (Ta = 25°C)
Parameter
Power supply voltage
Symbol
V
CC
Limits
4.5 ~ 13.0
Unit
V
1
Multimedia ICs
BA7631 / BA7631F
CC
=
•
Electrical characteristics (unless otherwise noted, Ta = 25°C and V
Parameter
Recommended operating voltage
Circuit current
Maximum output level
Voltage gain
Total harmonic distortion
Interchannel crosstalk
Input conversion noise voltage
CTL switch level
Input impedance
Not designed for radiation resistance.
12V)
Unit
V
mA
V
rms
dB
%
dB
µV
rms
V
kΩ
Conditions
—
—
f = 1MHz, THD = 0.5%
f = 1kHz, V
IN
= 3.0dBm
f = 1kHz, V
IN
= 3.0dBm
f = 10kHz, V
IN
= 3.0dBm
30kHz LPF, R
g
= 2.2kΩ
—
—
Symbol
V
CC
I
CC
V
om
G
V
THD
C
TM
V
Min.
V
TH
Z
IN
Min.
4.5
—
3.1
– 0.5
—
—
—
1.0
48.5
Typ.
12.0
14.9
3.6
0
0.005
– 75
20.0
2.0
65
Max.
13.0
24.0
—
0.5
0.1
– 60
40.0
3.0
80.5
•
Circuit operationBA7631F make it easy to construct a decoder for the scrambled pay channels. They have been
The BA7631 and
designed specifically for audio signal decoding. As shown in the application examples in Figs. 1 and 2, there are
inputs for TV, VCR, decoder, and AUX, to cover a wide range of applications. When the AUX input is not used, by
setting CTL5 to “L”, the system construction becomes the same as that of the BA7630S, and the BA7630S switching
logic can be used as is.
•
Application example
To VTR IN
CTL4 for SW3
from EXT OUT
22µF
+
1
2
BF
1
BF
16
15
22µF
+
To DECODER IN
CTL5 for SW2
CTL3 for SW2
To TV IN
CTL2 for SW1
22µF
+
V
CC
47µ
2
3
4
SW2
3
4
5
6
SW1
1
2
3
4
5
7
8
14
BF
13
12
11
22µF
+
+
22µF
+
from VTR OUT
from TV OUT
22
µ
F
from VTR
TUNER OUT
CTL1 for SW1
+
1
2
SW3
10
9
+
22µF
from
DECODER OUT
Fig.1
5
Microcontroller MCU
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