NJU72015
– 1 –
Ver.2.8E
2Vrms Ground Referenced Stereo Line Amplifier
GENER AL DESCRIPTION
The NJU72015 is an audio line Amplifier . It can swing
2Vrms (5.6V peak-to-peak) signal at 3.3V operating voltage.
Ground-referenced outputs eliminate output coupling
capacitor. It contains differential input.
The pop noise suppression circuit removes a pop noise at
the power-on and power-off.
AP PLICATIONS
Audio applications requiring 2Vrms outputs
FEATURES
Operating Voltage +3.0 to +3.6V
Operating Current IDD=5mA typ.at V+=3.3V, No Signal, No Load
Output C oupling Capac itor-less
Differential Input
Pop Noise Suppression C ircuit
C-MOS Technology
Pack age Outline SSOP14
BLOCK DI AGR AM PIN CONFIGURATION
PACKAGE OUTL INE
No.
Symbol
Function
1 +INL Lch Noninverted Input
2 -INL Lch Inverted Input
3 OUTL Lch Output
4 GND Ground
5 MUTE Mute Control
6 V- V- Power Supply
7 CN Flying Capacitor Negative Terminal
8 CP Flying Capacitor Positive Terminal
9 V+ V+ Power Supply
10
DGND Ground
11
UVP Undervoltage Protection Input
12
OUTR Rch Ou tput
13
-INR Rch Inverted Input
14
+INR Rch Noninverted Input
1
7
8
14
NJU72015V
1uF
1uF
2
External Under
Voltage Detector
+INL
OUTL
V+
CPCN
+INR
-INR
AGND UVP
1uF
3
4
5
1
13
12
11
10
14
V-
6
7
9
8
Charge
Pump
1uF
MUTE DGND
-INL
OUTR
Bias
V+
V+
10kΩ
20kΩ
10kΩ
20kΩ
20kΩ20kΩ
1uF10kΩ
1uF10kΩ
Active
Mute
NJU72015
– 2 –
ABSOLUTE MAXIMUM RATING (Ta=25C)
PARAM ET ER SYMBOL
RATING UNIT
Supply Voltage V+ +4 V
Power Dissipation PD 530(Note1)) mW
Maximum Input Voltage VIMAX -V+ -0.3 ~ V+ +0.3 V
Operating Temperature Range
Topr -40 ~ +85 C
Storage Temperature Range
Tstg -40 ~ +125 C
(Note1) EIA/JEDEC STANDA RD Te s t board (76.2x114.3x1.6mm, 2layer, FR-4 ) mounting
RECOMMENDED OPERATING CONDITIONS
(V+=3.3V, Ta=25C unless otherwise sp e cified)
PARAMETER SYMBOL
TEST C ONDITION MIN.
TYP.
MAX.
UNIT
Operating Voltage V+ 3.0 3.3 3.6 V
ELECTRICAL CHARACTERISTICS
DC CHARACTERISTICS
(V+=3.3V, Mute=OFF, RL=10kΩTa=25Cunless otherwise specified)
PARAMETER SYMBOL
TEST C ONDITION MIN.
TYP.
MAX.
UNIT
Operating Current IDD No signal, No load - 5 10 m A
Power Supply Rejection Ratio PSRR V+=3V to 3.6V - 80 - dB
External undervoltage detection Vuvp - 1.25
- V
External undervoltage detection
hysteresis current IHys - 5 - uA
Output Offset Voltage VOS Rg=0Ω - - 1 mV
AC CHARACTERISTICS
(V+=3.3V, f=1kHz, V i n=1 Vrms [differential input], Mute=OFF, RIN=10kΩ, Rfb=20kΩ, RL=10kΩTa=25C
unless otherwise specified)
PARAMETER SYMBOL
TEST C ONDITION MIN.
TYP.
MAX.
UNIT
Maximum Output Voltage Level VOMAX THD=1% - 2.3 - Vrms
Mute Level VMUTE Rg=0Ω, Mu te=ON - -80 - dB
Equivalent Input Noise Vo ltage VNI Rg=0Ω, A-weighted - -106
- dB
Total Harmonic Distortion THD BW:400Hz-22kHz - 0.003
- %
Channel Separation CS Rg=600Ω, Bandpass - 110 - dB
CONTRO L CHARACTERISTICS
(V+=3.3V, Ta=25C unless otherwise specified)
PARAMETER SYMBOL
TEST C ONDITION MIN.
TYP.
MAX.
UNIT
Mute terminal High MuteH Mute=OFF 0.7V+
- V+ V
Mute terminal Low MuteL Mute=ON 0 - 0.3V+ V
NJU72015
– 3 –
1uF
External Under
Voltage Detector
+INL
OUTL
V+
CPCN
+INR
-INR
AGND UVP
4
5
11
10
V-
6
7
9
8
Charge
Pump
1uF
MUTE DGND
-INL
OUTR
Bias V+
A
V+
20kΩ
2
1
3
13
12
14
1uF
1uF
2
External Under
Voltage Detector
+INL
OUTL
V+
CPCN
+INR
-INR
AGND UVP
1uF
4
5
1
13
12
11
10
14
V-
6
7
9
8
Charge
Pump
1uF
MUTE DGND
-INL
OUTR
Bias
V+
RL=10kΩ
RL=10kΩ
10kΩ
20kΩ
10kΩ
20kΩ
20kΩ20kΩ
1uF10kΩ
1uF 10kΩ
V+
20kΩ
V+
V V
3
A
V
RL=10kΩ
1uF
1uF
2
External Under
Voltage Detector
+INL
OUTL
V+
CPCN
+INR
-INR
AGND UVP
1uF
3
4
5
1
13
12
11
10
14
V-
6
7
9
8
Charge
Pump
1uF
MUTE DGND
-INL
OUTR
Bias
V+
V+
RL=10kΩV V
10kΩ
20kΩ
10kΩ
20kΩ
20kΩ20kΩ
1uF10kΩ
1uF10kΩ
Inverted Phase
Active
Mute
Vp
Vn
Vp
Vn
1uF
2
External Under
Voltage Detector
+INL
OUTL
V+
CPCN
+INR
-INR
AGND UVP
3
4
5
1
13
12
11
10
14
V-
6
7
9
8
Charge
Pump
1uF
MUTE DGND
-INL
OUTR
Bias
V+
RL=10kΩ
RL=10kΩ
20kΩ20kΩ
10kΩ
10kΩ
V+
20kΩ
VV
20kΩ
20kΩ
10kΩ
10kΩ1uF
1uF 1uF
1uF
V+
TEST CIRCUIT
♦IDD ♦PSRR
♦VUVP, IHys, VOMAX, VMUTE ♦VOS
NJU72015
– 4 –
1uF
1uF
2
External Under
Voltage Detector
+INL
OUTL
V+
CPCN
+INR
-INR
AGND UVP
1uF
4
5
1
13
12
11
10
14
V-
6
7
9
8
Charge
Pump
1uF
MUTE DGND
-INL
OUTR
Bias
V+
V+
RL=10kΩRL=10kΩ
V V
10kΩ
20kΩ
10kΩ
20kΩ
20kΩ20kΩ
1uF
10kΩ
1uF 10kΩ
V+
20kΩ
FilterFilter 3
1uF
1uF
2
External Under
Voltage Detector
+INL
OUTL
V+
CPCN
+INR
-INR
AGND UVP
1uF
3
4
5
1
13
12
11
10
14
V-
6
7
9
8
Charge
Pump
1uF
MUTE DGND
-INL
OUTR
Bias
V+
RL=10kΩRL=10kΩ
10kΩ
20kΩ
10kΩ
20kΩ
20kΩ20kΩ
1uF10kΩ
1uF10kΩ
V+
20kΩ
Inverted Phase
V+
Filter
V
Filter
V
Inverted Phase
Vp
Vn
Vp
Vn
1uF
1uF
1uF
2
External Under
Voltage Detector
+INL
OUTL
V+
CPCN
+INR
-INR
AGND UVP
1uF
3
4
5
1
13
12
11
10
14
V-
6
7
9
8
Charge
Pump
MUTE DGND
-INL
OUTR
Bias
V+
V+
RL=10kΩ
RL=10kΩ
V
10kΩ
20kΩ
10kΩ
20kΩ
20kΩ20kΩ
1uF10kΩ
1uF10kΩ
V+
20kΩ
Active
Mute
Vp
Vn
600Ω
Inverted Phase
600Ω
Inverted Phase
600Ω
600Ω
Vp
Vn
V
♦VNI ♦THD
VNI = Meas u rement - 12dB
♦CS
OUTL: CS = 20*Log(OUTR/OUTL)
OUTR: CS = 20*Log( OUTL/OUTR)
NJU72015
– 5 –
APPLICATION CIRCUIT
*1) Connect a zener diode between V- terminal and GND terminal to prevent connecting V- terminal[6pin] and V+ terminal[9pin].
2
External Under
Voltage Detector
+INL
OUTL
V+
CPCN
+INR
-INR
AGND UVP
4
5
1
13
12
11
10
14
V-
6
7
9
8
Charge
Pump
MUTE DGND
-INL
OUTR
Bias
V+
V+
RIN
Active
Mute
3
RIN RIN
RIN
CIN
CIN
CIN CIN
RFB
RFB
RFB
RFB
R11
R12
R13
CV-
D1
CFLY
1uF
NJU72015
– 6 –
Fig.1 NJU72015 Block diagram
Fig.2 Capac itor-free Operation
Technical Information
APPLICATION NOTES
♦Operating Overview
The drawing in Fig 1 illustrates the internal circuit in
NJU72015. The NJU72015 has a charge-pump for
negative power supply, pop noise suppression circuit ,
external under voltage detector, and a line amplifier .
The NJU72015 operates from a single supply
voltage from 3.0V to 3.6V and the NJU720 15’s line
drivers use a charge pump to invert the po sitive power
suppl y (V+) to negative power supply (V-), see Fig 2.
The output voltages are center ed at zero volts with the
capabi li ty to swing to the positive rail or negative rail.
This feature eliminates the output capacitor that is
using in conventional line dri ver operating by a
single-supply voltage.
♦Gain Setting Resistor
The drawing in Fig.1 illustrates the gain setting
circuit configuration of NJU72015. The differential
input gain of the NJU72015 is s et by:
IN
FB
VR
R
A
The value of Ga in setting resistors, RIN and RFB,
affect noise, stability and input capacitor size.
Selecting values that are too low demands a large
input ac-coupling capacitor, CIN. Selecting values that
are too high increases the noise of the am plifier.
♦Input Coupling Capacitor
An input capacitor, CIN, is required to be adde d in
series with the audio signal into the input pins of the
NJU72015. The capacitor allows the amplifier to bias
the input signal to the proper DC level for optimum
operation. These capacitors form a high-pass filter
with the input resistor, RIN. The cutoff frequency is set
by:
ININ
)HPF(C CR2 1
f
The value of CIN must be considered carefully
because it directl y affects the low frequency respo nse
and can distort the audio signal.
V+
GND
V+/2
VOUT
Conv entional Line Driv er
V+
V-
GN D
VOUT
NJU72015
2
Ex ternal Under
Voltage Detec tor
+INL
OUTL
V+
CPCN
+INR
-INR
AGND UVP
4
5
1
13
12
11
10
14
V-
6
7
9
8
Char ge
Pump
MUTE DGND
-INL
OUTR
Bias
V+
V+
RI N
Activ e
Mute
3
RI N RI N
RI N
CI N
CI N
CI N CI N
RFB
RFB
RFB
RFB
R1 1
R1 2
R1 3
CV -
D1
CFL Y
1uF
NJU72015
– 7 –
Fig.3 Flying capacitor @ 7pin/8pin
Fig.4 Decoupling capacitor @ 6pin
Fig.6 UVP function
●Application Circuit for Using UVP
●Application Circuit for Not Using UVP
● Sequence of UVP Function
Technical Information
♦Flying Capacitor
The flying c apacitor is required to generate a
negative power supply. To achieve a high efficiency,
low-ESR capacitors (ceramic capacitor) are to be
selected, and to be placed near the C P terminal (pin7)
and CN terminal (pin8) so as to reduce the resistance
caused by the PC B trace. The recommended val ue of
this capacitor is 1uF. Selecting values that are too low
m ight reduce the maximum output voltage and might
not be operated to specifications.
♦Negativ e suppl y decoupling Capacitor
To achieve a high efficiency on the neg ative voltage
regulator (negative supply for the amplifier circuit), low
ESR capacit o r (ceramic capacitor) is to be used for
this decoupling capacitor. This capacitor is to be
placed near the V- terminal (pin6) so as to reduce the
resistance caused by the PCB trace. The
recom mended value of this capacitor is 1uF.
♦Protection Diode
For protection purpose, it is advisable to place a low
Vf diode (Schottky diode) to Ground at V- terminal (pin
6). The external diodes will protect the IC n egative
suppl y terminal when a positive voltage is accidentally
applied to the pin.
Fig.5 Negative supply terminal @ 6pin
♦External Under Voltage Protection
External under voltage detectio n can be used to
m ute the NJU72015’s output befor e an input dev ic e
can gener ate a pop nois e.
The active-mute threshold at the UVP pin is 1.25V.
The user selects a r esistor divider to obtain the
active-mute threshold and hysteresis for the specif ic
application. The threshold is s et by:
12
1211
13
12
1211
12
1211
13
5251
251
5
RRR
R
V
RRR
V
RRR
RV
HYSUVP
HYS
).(
.
with the cond iti on R13 >> R11//R12
For example, to obtain VUVP=4V an d 1V hysteresis,
R11=3kΩ, R12=1kΩ and R13=50kΩ.
If the UVP function is not used, A pull-up
resistance,RPULL is to be connecte d between UVP
terminal and V+ terminal.
UVP11
R11
R12
R13
System Power
UVP
11
RPULL>10kΩ9V+
System Power
Output
Active
Mute
VUVP
VHYS
VUVP+VHYS
V-
6
CV- D1
6
CV- V-
7 8
CFLY
CN CP
NJU72015
– 8 –
Fig.7 Timing diagram when turning on power
supply and intercepting it
Technical Information
♦Power up & down sequence to minimize pop
noise
To further reduce pop noise, Recommend to Fig.7
how Power up and d own sequence.
When power supply is turned ON
To further reduce pop noise during power ON,
the MUTE terminal should switch L->H after
the power supply terminal has turned ON. It is
recommended to have a time interval of
10m sec (TON) or more between these two
transitions.
When power supply is turned OFF
To further reduce pop noise dur ing power
OFF, the MUTE terminal should switch H->L
after the power supply terminal has turned
OFF. It is recommended to have a time
interval of 10msec (TOFF) or more between
these two transitions.
Positive Power
Supply [9pin]
Mute
[5pin]
TON>10msec TOFF>10msec
NJU72015
– 9 –
Ver.2.8E
TERMINAL DESCRIPTION
Terminal
SYMBOL FUNCTION EQUIVALENT CIRCUIT VOLTA GE
1
2
13
14
+INL
-INL
-INR
+INR
AC Input
0V
2
9 OUTL
OUTR AC Outpu t
0V
5 MUTE MUTE Control
0V
7
8
9
CN
CP
DGND
Flying Capacitor
Negative Terminal
Flying Capacitor
Positive Terminal
Ground
-
-
0V
V+
V-
100Ω
GND
V-
V+
V-
V+
CN
DGND
CP
V+
V- GND
205kΩ
10kΩ
NJU72015
– 10 –
TERMINAL DESCRIPTION
Terminal
SYMBOL FUNCTION EQUIVALENT CIRCUIT VOLTA GE
11 UVP Undervoltage
Protection Input
-
V+
V- GND
100Ω
NJU72015
– 11 –
IDD vs Supply Voltage
N o Signal, No Load
0
2
4
6
8
10
01234
Supply Voltage [V]
IDD [mA]
ID D vs Supply Voltage
No Signal, No Load
0
2
4
6
2.5 2.6 2.7 2.8 2.9 3
Supply Voltage [V]
IDD [mA]
-40oC
25oC
85oC
105oC
-40/25oC
VDD=3V to 0VVDD=0V to 3V
85/105oC
IDD vs Tempreature
N o Signal, No Load
2
3
4
5
6
-50 0 50 100 150
Temperature [OC]
IDD [mA]
V+=3.0V
V+=3.3V
V+=3.6V
VSS vs Te mprea ture
No Signal, No Load
-4
-3.5
-3
-2.5
-2
-50 0 50 100 150
Temperature [OC]
VSS [V]
V+=3.6V
V+=3.3VV+=3.0V
PSR R vs Tempreature
V+=3V to 3.6V
-90
-85
-80
-75
-70
-65
-60
-55
-50
-50 0 50 100 150
Temperature [OC]
VSS [V]
PSRR vs Frequency
V +=3.3V , V ripple=100mVrms, RL=10kΩ, Bandpass
0
10
20
30
40
50
60
70
80
90
10 100 1000 10000 100000
Frequency [Hz]
PSRR [dB]
-40oC25oC
85/105oC
TYPICAL CHARACTERISTICS
NJU72015
– 12 –
Maximum Output Voltage vs Supply Voltage
f=1kHz, THD=1%, RL=10kΩ
1.8
2
2.2
2.4
2.6
2.8
3
2.5 3 3.5 4
Supply Voltage [V]
Maximum Output Voltage [Vrms] __
-40/25/85/105oC
Maximum Output Voltage vs Frequency
V+=3.3V, THD=1%, RL=10kΩ
2
2.1
2.2
2.3
2.4
2.5
2.6
10 100 1k 10k 100k
Frequency [Hz]
Maximum Output Voltage [Vrms] __
-40/25oC
85/105oC
UVP Control
V+=3/3.3/3.6V,VIN=1Vrms[differential], f=1kHz, RL=10kΩ,
R1=3kΩ, R2=1kΩ, R3=50k Ω, Ta=25oC
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10
2 3 4 5 6
UVP Input [V]
Voltage Gain [dB]
V+=3/3.3/3.6V
UVP OFF
UVP ON
UVP Control
V+=3.3V,VIN=1Vrms[differential], f=1kHz, RL=10kΩ,
R1=3kΩ, R2=1kΩ, R3=50k Ω, Ta=-40/25/85/105oC
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10
23456
UVP Input [V]
Voltage Gain [dB]
-40oC
-40oC
25/85/105oC
25/85/105oC
UVP ON
UVP OFF
UVP Control
V+=3/3.3/3.6V,VIN=1Vrms[differential], f=1kHz, RL=10kΩ
R1=3kΩ, R2=1kΩ, R3=50k Ω, Ta=25oC
0
1
2
3
4
5
6
7
2 3 4 5 6
UVP Input [V]
IHYS [uA]
V+=3/3.3/3.6V
UVP OFF
UVP ON
UVP Control
V+=3.3V,VIN=1Vrms[differential], f=1k Hz, RL=10kΩ
R1=3kΩ, R2=1kΩ, R3=50kΩ, Ta=-40/25/85/105oC
0
1
2
3
4
5
6
7
2 3 4 5 6
UVP Input [V]
IHYS [uA]
-40oC
-40oC
25/85/105oC
25/85/105oC
UVP OFF
UVP ON
TYPICAL CHARACTERISTICS
NJU72015
– 13 –
Maximum Output Voltage vs Temperature
V+=3.3V, f=1kHz, THD =1%, RL=10kΩ
2.2
2.25
2.3
2.35
2.4
-50 0 50 100 150
Temperature [OC]
Maximum Output Voltage [Vrms]
Lch/Rch
VMUTE vs Temperature
V+=3.3V, f=1kHz, VMUTE=Gv[MUTE]/Gv[ACTIVE], .A-weighted
-100
-95
-90
-85
-80
-75
-70
-65
-60
-50 0 50 100 150
Temperature [OC]
VMUTE [dB]
Lch / Rch
VNI vs Temperature
V+=3.3V, R g= 0Ω, A-w eighted
-120
-115
-110
-105
-100
-50 0 50 100 150
Temperature [OC]
VNI [dB]
Rch
Lch
THD+N vs Temperature
V+=3.3V,,VIN=1Vrms[differential], f=1kHz, RL= 10kΩ,
BW:400-22kHz
0.0001
0.001
0.01
0.1
1
10
-50 0 50 100 150
Temperature [OC]
THD+N [%] _
Lch/Rch
Mute Control
V+=3/3.3/3.6V,VIN=1Vrms[differential], f=1kHz, RL=10kΩ
Ta=25oC
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10
0 0.2 0.4 0.6 0.8 1
Mute Termina l [x V+]
Voltage Gain [dB]
ACTIVE→MUTE MUTE→ACTIVE
V+=3V
V+=3.3V
V+=3.6V
Mute Control
V+=3.3V,VIN=1Vrms[differential], f=1kHz, R L=10kΩ
Ta=-40/25/85/105oC
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10
0V+ 0.2V+ 0.4V+ 0.6V+ 0.8V+ 1V+
Mute Terminal [V]
Voltage Gain [dB]
MUTE→ACTIVEACTIVE→MUTE
25oC-40oC
85/105oC
TYPICAL CHARACTERISTICS
NJU72015
– 14 –
THD+N vs Output Voltage
V+=3.3V, f=1kHz, BW:10-22k Hz, RL=10kΩ
0.0001
0.001
0.01
0.1
1
10
0.01 0.1 1 10
Output Voltage [Vrms]
THD+N [%]
-40/25/85/105oC
THD+N vs Output Voltage
V+=3.3V, f=10kHz, BW:10-80kHz, RL=10kΩ
0.0001
0.001
0.01
0.1
1
10
0.01 0.1 1 10
Output Voltage [Vrms]
THD+N [%]
-40/25/85/105oC
THD+N vs Output Voltage
V+=3.3V, f=100Hz, BW:10-22kHz, RL=10kΩ
0.0001
0.001
0.01
0.1
1
10
0.01 0.1 1 10
Output Voltage [Vrms]
THD+N [%]
-40/25/85/105oC
THD+N vs Frequency
V+=3.3V, Vo=1. 8Vrms, BW:10-80k Hz
0.0001
0.001
0.01
0.1
1
10
10 100 1000 10000 100000
Frequency [Hz]
THD+N [%]
-40/25oC
85/105oC
THD+N vs Frequency
V+=3.3V, Vo=2.0V rms, BW:10-80kHz
0.0001
0.001
0.01
0.1
1
10
10 100 1000 10000 100000
Frequency [Hz]
THD+N [%]
-40oC25oC
85oC105oC
THD+N vs Output Voltage
V+=3.3V, BW:10-22kHz(f=100/1kHz), 10-80kHz(f=10kHz)
0.0001
0.001
0.01
0.1
1
10
0.01 0.1 1 10
Output Voltage [Vrms]
THD+N [%]
f=10kHz
f=100Hz
f=1kHz
TYPICAL CHARACTERISTICS
NJU72015
– 15 –
Output Voltage vs Load Resistance
V+=3.3V, f=1kHz, THD =1%
1
1.5
2
2.5
3
100 1k 10k 100k
Load Resistance [Ω]
Output Voltage [Vrms]
-40/25/85/105oC
Channel Separation vs Frequency
V+=3.3V, VO= 2Vrms, Rg=600Ω, BW:Ban dPass, RL=10kΩ
60
70
80
90
100
110
120
130
140
150
160
10 100 1000 10000 100000
Frequency [Hz]
Channel Separation [dB]
Lin - Rout
Rin - Lout
Cha nnel Se pa ration vs Fre quency
V+=3.3V, V O=2Vrms, R g=600Ω, BW:BandPass, RL=10kΩ
60
70
80
90
100
110
120
130
140
150
160
10 100 1000 10000 100000
Frequency [Hz]
Channel Separation [dB]
-40/25/85/105oC
Negative Supply Voltage vs Load Current
V+=3.3V, N o Signal, No Load
-3.3
-3.2
-3.1
-3
-2.9
-2.8
0 5 10 15
Load Current [mA]
Negative Supplyt Voltage [Vrms]
25oC
85oC
105oC
-40oC
TYPICAL CHARACTERISTICS
[CAUTION]
The specifications on thi s databook are only
given for information , without any guarantee
as regards ei ther 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 ri ght including
the industrial rights.
