AN5272

AN5272, Serwisówki TV, Układy Scalone

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ICs for Audio Common Use
) Power Amplifier with
Variable Audio Output and Volume Control
2 (18 V, 8
W
Unit : mm
Overview
The AN5272 is a monolithic integrated circuit designed
for 4.0 W (18 V, 8 W) output audio power amplifier. It is
a dual channel SEPP IC suitable for stereo operation in
TV application.
7.7
0.3
3.6
Features
· Built-in DC volume control
· Built-in thermal protection circuit
· Built-in over current protection circuit
· 2 Variable Audio Output (VAO)
· V
CC
operating range : 12.2 V to 27.5 V
R1.8
(12.5)
(1.2)
19.1
±
0.3
21.9
±
0.3
Applications
· TV
HSIP012-P-0000A
n
Block Diagram
Volume
Ripple
filter
Over
current
thermal
protection
circuit
1
AN5272
4.0 W
´
n
±
f
n
n
AN5272
ICs for Audio Common Use
n
Pin Descriptions
Pin No.
Description
Pin No.
Description
1
Variable audio output 1
7
Ch.2 output
2
Ch.1 input
8
Negative feedback ch.2
3
Volume control
9
GND
4
Variable audio output 2
10
V
CC
5
Ch.2 input
11
Negative feedback ch.1
6
Ripple filter
12
Ch.1 output
n
Absolute Maximum Ratings
Parameter
Symbol
Rating
Unit
Supply voltage
V
CC
30
V
Supply current
I
CC
3.5
A
Power dissipation
*
2
P
D
37.5
W
Operating ambient temperature
*
1
T
opr
-25 to +75
°C
Storage temperature
*
1
T
stg
-
55 to
+
150
°
C
Note) *
1
:T
a
= 25 °C except power dissipation, operating ambient temperature and storage temperature.
*
2
: Power dissipation of the package at T
a
= 75 °C.
n
Recommended Operating Range
Parameter
Symbol
Range
Unit
Supply voltage
V
CC
12.2 to 27.5
V
n
Electrical Characteristics at V
CC
=
18 V, f
=
1 kHz, R
L
=
8
W
, T
a
=
25
°
C
Parameter
Symbol
Conditions
Min Typ Max Unit
Quiescent current
I
CQ
No input signal
17
25
33
mA
Voltage gain
G
V
V
IN
= 90 mV
28
30
32
dB
Total harmonic distortion
*
1
THD V
IN
= 90 mV
0.3
1.0
%
Output power
*
1
P
O
THD = 10 %
3.6
4.1
W
Channel balance
CB
V
IN
= 90 mV
-1
0
1
dB
Max. volume attenuation
*
1
Att
V
IN
= 90 mV
-70
-64
dB
VAO voltage gain
G
VAO
V
IN
= 90 mV
10
12
14
dB
Output noise voltage
*
1
V
NO
R
g
= 10 kW, Din-Audio Filter
0.6
1.0 mV[rms]
Note) *
1
: With a filter band from 20 Hz to 20 kHz used.
2
ICs for Audio Common Use
AN5272
n
Application Circuit Example
AN5272
1 mF
5 V
1 mF
20 kW
20 kW
1 mF
1 mF
100 m
F
1000
10 mF
0.047
mF
0.047
mF
1000
m
F
10 mF
10 kW
m
F
1000
m
F
R
L
= 8 W
20 W
1 kW
1 kW
20 W
R
L
= 8 W
Variable audio
output 1
Variable audio
output 2
18 V
n
Usage Notes
1) Depending on the maximum application output power, external heatsink may be needed.
External heatsink should be fixed to the chassis.
2) Fin of the IC can be connected to GND.
3) Please prevent output to V
CC
short and output to GND short.
4) The temperature protection circuit will operate at T
j
around 150
C. However, if the temperature decreases, the
protection circuit would automatically be deactivated and resume normal operation.
°
3
AN5272
ICs for Audio Common Use
Technical Information
1.Characteristic Curve Chart
P
O
, THD ¾ V
IN
G
V
, THD ¾ f
10
100
V
CC
= 18 V
R
L
= 8 W
f = 1 kHz
Vol. = max.
30
G
V
28
1
P
O
10
26
V
CC
= 18 V
R
L
= 8 W
V
IN
= 90 mV
Vol. = max.
24
1.0
22
0.8
0.1
THD
1
0.6
0.4
THD
0.2
0.01
0.1
0
1
10
100
1000
10
100
1k
10k
100k
Input voltage V
IN
(mV)
Frequency f (Hz)
G
VAO
¾ f
P
O
¾ V
CC
14
10
1 kHz
THD
=
=
10 %
12
G
V
Vol.
=
max.
8
10
R
L
= 8 W
8
6
V
CC
=
18 V
6
R
L
=
8
W
R
L
=
16
W
V
IN
=
90 mV
4
Vol.
=
max.
4
2
2
0
0
10
100
1k
10k
100k
10
12
14
16
18
20
22
24
26
28
Frequency (Hz)
Supply voltage V
CC
(V)
DC volume characteristics
P
D
¾ T
a
V
CC
= 18 V
R
L
= 8 W
V
IN
= 90 mV
f = 1 kHz
62.5
7
R
th( j-c)
=
2
°
C/W
60
C/W
1. No heat sink
2. 10
=
42
°
0
C/W heat sink
3. 5 °C/W heat sink
4. 3
°
50
-10
C/W heat sink
5. 2 °C/W heat sink
6. 1
°
41.7
6
-
20
40
C/W heat sink
7. Infinity heat sink
°
-30
31.3
5
4
-40
25
20
17.9
3
-
50
10.4
2
10
-60
1
3.0
-70
0
1
2
3
4
5
0
0
25
50
75
100
125
150
DC volume (V)
पғԹ౓ T
a
(°
C)
4
n
f
R
th( j-a)
30
ICs for Audio Common Use
AN5272
Technical Information (continued)
2.Application Note
1) Voltage gain
The voltage gain of the AN5272 can be varied by changing the resistor R2 as shown below :
G
VI
Pin7,12
R1 is always fixed at 20 kW.
R2 is variable.
G
VO
= 20 log (R
1
/R
2
)
4 dB
which is fixed in
internal circuit.
=
Pin8
11
R1
Typical values are : R
1
= 20 kW, R
2
= 1 kW
C
NF
=
10
m
F
G
VO
= 20 log (20 k/1 k)
= 26 dB
R2
G
VTOTAL
= G
VI
+ G
VO
= 4 dB + 26 dB
= 30 dB
2) DC volume control
The DC volume control range is 0 V to 5 V. This range is used in order to be easily controlled by micro-computer
using PWM output. The recommended circuit and volume attenuation characteristic are shown below :
AN5272
Volume
attenuation
Microcomputer IC
R4
18 kW
R5
12 kW
PWM
output
3
0
0 W
3
Volume
control
C4
2.2 mF
0 0.6
Volume at Pin3
5 (V)
Fig. Volume control interface circuit for AN5272
Fig. Volume characteristic of AN5272
3) Oscillation
To prevent oscillation, it is advisable to use RC (Zobel network) at output. C of polyester film capacitor has smaller
characteristic fluctuation with temperature and frequency. The resistor R connected in series with C is effective for
phase correction at high frequency, and as a result, it improves the oscillation allowance.
Pin
12
1000 mF
C
0.047 mF
R
20 W
R
L
= 8 W
5
n
G
V
input
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