ICs for TV
1
AN5285K
Sound level automatic gain control IC
s
Overview
The AN5285K is a stereo automatic volume control
IC for reducing a difference in volume between broad-
casting stations and between programs. It is a kind of
AGC circuit and reduces a sudden change in sound sig-
nal amplitude by using a proper time constant.
s
Features
Sound level AGC function by VCA gain control
Prevention of S/N ratio degradation by reducing VCA
gain at no signal (typ. 20 mV[rms] or less)
AGC function can be switched on and off externally.
Operating point of VCA gain lowering is adjustable by
means of external resistor.
Usable for stereo sound system (also usable for monau-
ral sound system) by two VCAs
s
Applications
Televisions and video sets
SSIP010-P-0000
Unit: mm
s
Block Diagram
10
1.10.25
1.650.25
0.25
3.00.3
0.5
1.1
1.778
+0.1
0.05
1
6.00.3
(12.0)
18.240.3
3.50.25
50 k
50 k
V
REF
5
LS1
2
LS2
9
GND
6
VCA
VCA
CTL
SW
Level
sensor 1
ROUT
8
RIN
10
CTL
7
LIN
1
LOUT
3
Level
sensor 2
Level
sensor 1
V/l reg.
V
CC
4
AN5285K
ICs for TV
2
Parameter
Symbol
Rating
Unit
Supply voltage
V
CC
13.0
V
Supply current
I
CC
30
mA
Power dissipation
P
D
390
mW
Operating ambient temperature
*
T
opr
-
20 to
+
75
C
Storage temperature
*
T
stg
-
55 to
+
150
C
Parameter
Symbol
Range
Unit
Supply voltage
V
CC
8.5 to 12.5
V
s
Recommended Operating Range
Note) * : Except for the operating ambient temperature, and storage temperature, all ratings are for T
a
=
25
C.
s
Absolute Maximum Ratings
s
Electrical Characteristics at V
CC
=
12 V, f
IN
=
1 kHz, T
a
=
25
C
Parameter
Symbol
Conditions
Min
Typ
Max
Unit
Supply current
*
I
CC
Without input signal
5
10
15
mA
Input and output level 1
*
V1
V
IN
=
1 mV[rms]
0.7
1.0
1.4
mV[rms]
Input and output level 2
*
V2
V
IN
=
50 mV[rms]
80
110
140
mV[rms]
Input and output level 3
*
V3
V
IN
=
200 mV[rms]
150
200
250
mV[rms]
Input and output level 4
*
V4
V
IN
=
1 V[rms]
200
280
360
mV[rms]
Input and output level 5
V5
V
IN
=
100 mV[rms], V
ctl
=
2.5 V
50
100
150
mV[rms]
Input and output level 6
V6
V
IN
=
300 mV[rms], V
ctl
=
4.5 V
230
300
370
mV[rms]
Total harmonic distortion
*
THD
V
IN
=
200 mV[rms]
0.1
0.5
%
Noise level
*
V
n
No input signal (with IHF-A)
100
V[rms]
Maximum input level
*
V
max
Input level at THD
=
1%
2.8
V[rms]
Crosstalk between channels
GT
V
IN
=
2 V[rms], AGC off
60
dB
AGC OFF voltage
V
SW
V
IN
=
1 V[rms], V
ctl
=
1.2 V
890
1 000 1 130 mV[rms]
Channel balance
*
CB
V
IN
=
200 mV[rms]
-
1.0
0
1.0
dB
Frequency characteristics
*
FC
V
IN
=
200 mV[rms]
-
1.0
0
1.0
dB
Level difference of f
IN
=
1 kHz/20 kHz
Input and output level 7
V7
V
IN
=
200 mV[rms], AGC off
175
200
225
mV[rms]
Note) * : V
ctl
=
3.5 V.
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