NJM2171A
LOW VOLTAGE HEADPHONE AMPLIFIER for PORTABLE AUDIO
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GENERAL DESCRIPTION
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PACKAGE OUTLINE
The NJM2171A is a low voltage headphone amplifier
designed for portable audio items.
The NJM2171A operates directly for battery supply. It
includes mute and standby circuit which require few external
components and realize low current consumption and very low
turn-noise at standby mode.
It is suitable for portable Mini-Disc, portable Compact-Disc,
and other headphone amplifier application.
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FEATURES
q
Operating Voltage V
+
1=1.8 to 4.5V
V
+
2=0.9 to 4.5V
q
Operating Current 450
A typ. @V
+
1=2.3V
700
A typ. @V
+
2=1.2V
q
Supply Current in Power Down Mode
10
A typ. @V
+
1=2.3V
25
A typ. @V
+
2=1.2V
q
Output Power Exceeds 5mW R
L
=16
@THD=10%
q
Fixed Voltage Gain 11.5dB typ.
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Package Outline VSP10
q
Bipolar Technology
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PIN CONFIGURATION
BIAS
1
2
3
4
10
9
8
7
MUTE
6
AMP1
5
AMP2
NJM2171AR
PIN FUNCTION
1.V
+
2
2.OUT1
3.IN1
4.STBY
5.V
+
1
6.V
REF
7.MUTE
8.IN2
9.OUT2
10.GND
NJM2171A
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ABSOLUTE MAXIMUM RATINGS (Ta=25
C)
PARAMETER
SYMBOL
RATINGS
UNIT
Supply Voltage
V
+
5
V
Power Dissipation
P
D
(VSP8) 320
mW
Operating Temperature Range
Topr
-20 to +75
C
Storage Temperature Range
Tstg
-40 to +125
C
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RECOMMENDED OPERATING CONDITIONS (Ta=25
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PARAMETER
SYMBOL
MIN.
TYP.
MAX.
UNIT
Operating Voltage Range1
V
+
1
1.8
2.3
4.5
V
Operating Voltage Range2
V
+
2
0.9
1.2
4.5
V
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ELECTRICAL CHARACTERISTICS (V
+
1=2.3V,V
+
2=1.2V,Rg=600
,R
L
=16
,f=1kHz,Ta=25
C)
PARAMEETER
SYMBOL
TEST CONDITION
MIN.
TYP.
MAX.
UNIT
I
CC
0
V
+
1=0V(1pin)
-
-
1
I
CC
1
STANDBY ON,MUTE ON(1pin)
-
25
40
I
CC
2
STANDBY ON,MUTE ON(5pin)
-
10
15
I
CC
3
No signal(1pin)
-
700
1200
I
CC
4
No signal(5pin)
-
450
700
A
I
CC
5
P
O
=0.5mW+0.5mW(1pin)
-
5.5
-
Operating Current
I
CC
6
P
O
=0.5mW+0.5mW(5pin)
-
0.8
-
mA
Reference Voltage
V
REF
No signal
0.55
0.60
0.65
V
Closed Loop Gain
G
V
V
IN
=-30dBV
10.5
11.5
12.5
dB
P
O
1
THD=10%
5.0
8.5
-
Output Power
P
O
2
V
+
1=1.8V,V
+
2=0.9V,THD=10%
2.0
4.0
-
mW
THD1
Po=1mW,R
L
=16
-
0.15
0.3
Total Harmonic Distortion
TED2
Po=5mW,R
L
=16
-
0.4
0.6
%
Output Noise Voltage
V
NO
A-Weighted
-
-100
-96
dBV
Crosstalk
CT
V
IN
=-30dBV
-
-80
-70
dBV
Mute Level
MUTE
MUTE-ON,V
IN
=-30dBV,A-Weighted
-
-95
-80
dBV
SVR1
V
+
1=1.8V+0.1Vrms, V
+
2=0.9V
60
70
-
Supply Voltage Rejection
Ratio
SVR2
V
+
1=1.8V, V
+
2=0.9V+0.1Vrms
60
70
-
dB
NJM2171A
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CONTROL TERMINAL CHARACTERISTICS
PARAMETER
SYMBOL
TEST CONDITION
MIN.
TYP.
MAX.
UNIT
High Level Input Voltage
V
IH
STBY(4pin), MUTE(7pin)
1.2
-
V
+
1
V
Low Level Input Voltage
V
IL
STBY(4pin), MUTE(7pin)
0
-
0.3
V
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CONTROL TERMINAL EXPLANATION
STBY (4Pin)
PARAMETER
CONTROL SIGNAL
STATUS
STANDBY ON
H
IC is non-active.
STANDBY OFF
L
IC is active.
MUTE (7Pin)
PARAMETER
CONTROL SIGNAL
STATUS
MUTE ON
H
IC doesn't output the signal.
MUTE OFF
L
IC output the signal.
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APPLICATION CIRCUIT
BIAS
1
2
3
4
10
9
8
7
MUTE
6
AMP1
5
AMP2
V
+
2
OUT1
IN1
16
100k
STBY ON
STBY OFF
0.47
F
OUT2
16
0.47
F
MUTE ON
MUTE OFF
100k
IN2
V
+
1
1
F
1
F
330
F
330
F
22
F
22
F
22
F
[CAUTION]
The specifications on this databook are only
given for information , without any guarantee
as regards either mistakes or omissions. The
application circuits in this databook are
described only to show representative usages
of the product and not intended for the
guarantee or permission of any right including
the industrial rights.
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