1
Video ICs
VCR standard audio signal processor
BA7795LS / BA7795FS
The BA7795LS and BA7795FS are standard audio signal processor ICs. They contain a playback preamplifier, line
amplifier, recoeding amplifier, ALC circuit, EQ switch circuit and high-voltage head switch, and provide all of the functions
required for normal-audio signal processing on a single IC with a minimum number of external components required.
Applications
Video cassette recorders and tape decks
Features
1) Available in compact SZIP and SSOP-A24-pin pack-
ages.
2) High-with standing-voltage head switch (AC with
standing voltage: Min. 80V
P-P
(f = 70kHz) ).
3) Simple, three-mode EQ switch built-in (BA7795LS).
4) Built-in LINE / TUNER selector switch.
5) High-performance low-noise playback amplifier.
Input conversion noise figure 122dBV
(Typ. Rg = 680, DIN AUDIO).
6) ALC level can be varied.
7) ALC loop external mute eliminates audible noise at
power on, and ALC attack noise.
8) Signal processing circuit can be constructed with the
addition of just a few external components.
Block diagram
1
3
5
7
9
11
13
15
17
19
21
23
24
22
20
18
16
14
12
10
8
6
4
2
PB IN
GND
PB NFB
PB EQ
PB OUT
PB LINE IN
ALC FILTER
LINE IN
TUNER IN
GND
LINE OUT
REC / EE CTRL
HEAD EQ
REC HSW
RIPPLE FILTER
V
CC
EQ CTRL
PB / TU / EE CTRL
BIAS
MUTE CTRL
REC NFB
ALC LEVEL
REC OUT
REC EQ
ALC
20dB
PB
MUTE
BF
REC
8dB
TUNER
8dB
LINE
LINE
+ 20dB
BIAS
SP
PB
REC
EP
LP +
REC
EP
BA7795LS
The BA7795FS has a different pin
layout to the BA7795LS.
2
Video ICs
BA7795LS / BA7795FS
Pin descriptions
BA7795LS Pin No.
BA7795FS Pin No.
Pin name
Function
1
7
HEAD EQ
2
8
PB IN
3
9
REC HSW
4
10
GND
5
11
RIPPLE FILTER
6
12
PB NFB
7
13
V
CC
8
14
PB EQ
9
15
EQ CTRL
10
16
PB OUT
11
17
PB / TU / EE CTRL
12
18
PB LINE IN
13
19
ALC LEVEL
14
20
ALC FILTER
15
21
BIAS
16
22
LINE IN
17
23
MUTE CTRL
18
24
TUNER IN
19
1
REC NFB
20
2
GND
21
3
REC OUT
22
4
BF OUT
23
5
REC EQ
24
6
REC / EE CTRL
Head resonance capacitor switch
Playback amplifier input / playback head switch
High-withstanding voltage recording head switch
GND (playback amplifier)
Ripple filter
Playback amplifier feedback
Power supply
Playback EQ switch
EQ control
Playback amplifier output
PB / TU / EE control (PB / EE control)
Playback line amplifier
ALC level setting
ALC filter time constant
Bias
Line input
MUTE control
Tuner input (REC / EE control)
Recording amplifier feedback
GND
Recording amplifier output
Line amplifier output
Recording EQ switch (recording EQ switch 2)
REC / EE control (recording EQ switch 1)
Absolute maximum ratings (Ta = 25C)
Recommended operating conditions (Ta = 25C)
Parameter
Symbol
Limits
Unit
V
CC
13
V
BA7795LS
Pd
mW
BA7795FS
Topr
C
Tstg
C
400
1
800
2
10 ~ + 65
55 ~ + 125
1 Reduced by 4.0mW for each increase in Ta of 1
C over 25
C.
2 Reduced by 8.0mW for each increase in Ta of 1
C over 25
C.
Applied voltage
Power
dissipation
Operating temperature
Storage temperature
Parameter
Symbol
Limits
Unit
7.5 ~ 12.5
V
V
CC
Power supply voltage
3
Video ICs
BA7795LS / BA7795FS
Electrical characteristics (unless otherwise noted, Ta = 25C, V
CC
= 9V, and f = 1kHz)
Parameter
Symbol
Min.
Typ.
Max.
Unit
Conditions
I
qEE
6.3
8.3
10.8
mA
I
qPB
6.3
8.3
10.8
mA
I
qREC
4.9
6.4
8.4
mA
G
VCP
27.0
28.0
29.0
dB
V
O
= 8dBV
G
VCL
19.0
20.0
21.0
dB
V
O
= 8dBV
THD
L
--
0.1
0.3
%
V
O
= 8dBV, R
L
= 4.7k
1
V
OmL
5.0
7.2
--
dBV
THD = 1%, R
L
= 4.7k
1
V
NOL
--
81.5
75
dBV
R
g
= 4.7k
, DIN AUDIO
V
OA
7.0
6.0
5.0
dBV
R
1
/ R
2
= 8.2 / 39k
V
IN
= 23dBV
THD
A
--
0.18
0.5
%
V
IN
= 23dBV, R
L
= 4.7k
1
MT
--
82.5
72
dB
Vo = 0dBV, DIN AUDIO
G
VCR
19.0
20.0
21.0
dB
THD
R
--
0.03
0.3
%
V
O
= 8dBV
V
OmR
5.5
7.4
--
dBV
V
O
= 8dBV, R
L
= 4.7k
1
G
VOR
65
77
--
dB
THD = 1%, R
L
= 4.7k
1
G
VOP
62
68
--
dB
V
NINP
--
122.5 114
dBV
R
g
= 680
, DIN AUDIO
G
VCP-L
56
57.5
59
dB
PB IN
BF OUT
R
PH
--
11
20
R
RH
--
11
20
BV
RHAC
80
100
--
V
P-P
f = 70kHz
LINE, TUNER input
REC OUT
1 Measured at BW = 400Hz to 30kHz.
When no signal
When no signal
When no signal
Quiescent current EE
Quiescent current PB
Quiescent current REC
Line amplifier
Power supply gain (PB input)
Power supply gain (LINE1, LINE2, TU inputs)
Distortion
Maximum output level
Output residual noise
ALC level
ALC distortion
Mute attenuation ratio
Recording amplifier
Voltage gain
Distortion
Maximum output level
Open loop gain
Playback preamplifier
Open loop gain
Input conversion noise
Total gain
Head switch
PB head switch impedance
REC head switch impedance
REC head switch AC withstanding voltage
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