NJM2761
Audio Limiter
 GENERAL DESCRIPTION
The NJM2761 is the audio limiter for speaker protection.
The limit level is adjustable by external resistor.
It is suitable for PC, potable audio and others.
 PACKAGE OUTLINE
NJM2761RB2
 FEATURES
 Wide Operating Voltage
 Variable Limit Level by external resistor
 Low Output Noise
 Bipolar Technology
 Package Outline
NJM2761V
+2.7V to +13.0V
0.2 to1V
-90dBV max.
TVSP10, SSOP14
 BLOCK DIAGRAM
Vcc
Vref
INa
OUTa
INb
OUTb
SW
INT
Ver.0.5E
SENSE
-1-
NJM2761
 PIN CONFIGURATION
TVSP10
1
10
2
9
3
8
4
7
5
6
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
V+
OUTa
INa
INT
VREF
SENCE
SW
INb
OUTb
GND
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
V+
OUTa
INa
INT
VREF
NC
NC
NC
NC
SENCE
SW
INb
OUTb
GND
SSOP14
-2-
1
14
2
13
3
12
4
11
5
10
6
9
7
8
NJM2761
ABSOLUTE MAXIMUM RATING (Ta=25C)
PARAMETER
SYMBOL
+
RATINGS
UNIT
14
V
Supply Voltage
V
Power Dissipation
PD
320(TVSP10)
300(SSOP14)
mW
Operating Temperature Range
Topr
-20 to +75
C
Storage Temperature Range
Tstg
-40 to +125
C
ELECTRICAL CHARACTERISTICS
+
 POWER SUPPLY (Ta=25C, V =5V unless otherwise specified)
PARAMETER
SYMBOL
TEST CONDITION
MIN.
TYP.
MAX.
UNIT
-
2.7
5.0
13.0
V
+
Operating Voltage
V
Operating Current
ICC
No Signal
-
1.5
2.0
mA
Reference Voltage
Vref
No Signal
2.2
2.5
2.7
V
 AC CHARACTERISTICS
+
(Ta=25C, V =5V, VIN=1Vrms/f=1kHz, Rsense=20k, BW=400-30kHz unless otherwise specified)
PARAMETER
Limit Level 1
SYMBOL
TEST CONDITION
GLIM1
+
MIN.
TYP.
MAX.
UNIT
150
200
250
mVrms
Limit Level 2
GLIM2
V =13V,Rsense=4k,VIN=2Vrms
0.7
1.0
1.3
Vrms
Limit Off
GOFF
SW=2V
0.9
1.0
1.1
Vrms
Output Noise
VNO
-
-100
(10)
-90
(31.6)
dBV
(Vrms)
THD+N
-
-
1
%
CT
-
-
-70
dB
-
-70
(316)
dBV
(Vrms)
Total Harmonic Distortion
Cross Talk
Ripple Rejection
RR
RS=0, A-weighting,
Vripple=100mVrms, f=1kHz
-
+
 CONTROL CHARACTERISTICS (Ta=25C, V =5V unless otherwise specified)
PARAMETER
SYMBOL
TEST CONDITION
MIN.
TYP.
MAX.
UNIT
Low Level Input Voltage
VIL
-
-
-
0.5
V
High Level Input Voltage
VIH
-
2.0
-
-
V
CONTROL TERMINAL EXPLANATION
SW(TVSP10:7pin, SSOP14:11pin)
MODE
STATUS
NOTE
Limiter ON
L
Limiter is active.
Limiter OFF
H
Limiter is not active.
-3-
NJM2761
TERMINAL DESCRIPTION
No,
SYMBOL
TVSP10(SSOP14)
FUNCTION
1
V+
Power Supply Terminal
2
9(13)
OUTa
OUTb
Ach Output Terminal
Bch Output Terminal
EQUIVALENT CIRCUIT
VOLTAGE
-
OUTa
OUTb
100
V+/2
1k
3
8(12)
INa
INb
INa
INb
Ach Input Terminal
Bch Input Terminal
V+/2
96k
48k
4
INT
Smoothing Capacitor
Connection
Terminal
INT
400
0.7V
300k
5
VREFIN
Reference Voltage Stabilizing
Capacitor Connection Terminal
VREFIN
300k
V+/2
300k
-4-
NJM2761
TERMINAL DESCRIPTION
No.
SYMBOL
TVSP10(SSOP14)
FUNCTION
EQUIVALENT CIRCUIT
VOLTAGE
12k
6(10)
SENSE
Resister Connection Terminal
for Limit Level Setting
7(11)
SW
Limiter ON/OFF Switch
SENSE
0V
SW
150k
270k
10(14)
GND
Ground Terminal
-
-5-
NJM2761
APPLICATION CIRCUIT
TVSP10
V+
0.22μF
GND
10
OUTb
9
INa
INb
8
4
INT
SW
7
5
VREF
SENSE
6
1
V+
2
OUTa
3
1μF
1μF
0.22μF
0.022μF
0.22μF
0.22μF
RSENSE
V
+
SSOP14
0.22uF
1uF
0.22uF
0.022uF
0.22uF
G ND
1
V+
2
O UTa
3
IN a
IN b
4
IN T
SW
5
VR EF
O UTb
SEN SE
14
13
12
1uF
0.22uF
11
10
RSE NSE
6
NC
NC
9
7
NC
NC
8
* The limit level is twice as much as set point when a signal is input into a either one channel of Ach or
Bch.
* For the above reason, monaural signal should input both INa and INb.
RSENSE=4000/Vlim[Ohm]
Vlim:
Limit level(Vrms)
Limit range:
200mVrms to 1Vrms (20k to 4kOhm)
* Please be careful of leakage current from the surrounding wiring because the INT terminal is high
impedance.
-6-
NJM2761
TYPICAL CHARACTERISTICS
V+ - Icc
Icc-Temperature
V+=5V,No-Signal,Limiter=ON,Rsense=20k 
2
2
1.5
Icc[mA]
Icc[mA]
1.5
1
0.5
0
V+=5V,No-Signal,Limiter=ON,Rsense=20k 
1
0.5
0
5
10
0
15
-20
0
20
40
60
80
o
Vcc[V]
Temperature [C ]
Limit Response-V +
Limit Response-Rsense
Vin=0dBV,Limiter=ON,Rsense=20k 
V+=5V,f=1kHz,Limiter=ON
Rsense=4k
1
1
V+=5.0V
Rsense=20k
0.1
0.01
0.01
0.1
Output[Vrms]
Output [Vrms]
Rsense=8k
V+=2.7V
0.1
V+=13.0V
0.01
0.01
1
0.1
Input[Vrms]
1
Input[Vrms]
Limit Response-Temperature
Vom
V+=5V,Vin=0dBV,Limiter=ON,Rsense=20k 
10
f=1kHz,Limiter=OFF,Rsense=20k 
1
+
V =2.7V
0.1
o
V =5.0V
75C o
1
THD[%]
Output [Vrms]
+
-20C
25C o
+
V =13.0V
0.1
0.01
0.01
0.1
Input[Vrms]
1
0.01
0.0001
0.001
0.01
0.1
1
Input[Vrms]
-7-
NJM2761
TYPICAL CHARACTERISTICS
THD-Vcc
10
THD-Temperature
f=1kHz,Limiter=ON,Rsense=20k 
10
V+=5V,Vin=0dBV,Limiter=ON,Rsense=20k 
+
V =2.7V
+
V =5.0V
THD[%]
1
THD[%]
1
+
V =13.0V
0.1
-20C o
0.1
75C o
25C o
0.01
0.001
0.01
0.1
0.01
0.001
1
0.01
Input[Vrms]
1
Input[Vrms]
Ripple Rejection
Cross Talk
-60
0.1
V+=5V,Vin=0dBV,Limiter=ON,Rsense=20k 
0
V+=5V,Vripple=100mVrms,Limiter=ON
-65
-20
-75
Ripple[dBV]
Cross Talk[dB]
-70
-80
25C
-85
o
75C
o
-90
25C o
-20C
-60
o
-80
-95
-100
-40
-20C o
100
75C o
1000
Frequency[Hz]
10000
-100
100
1000
10000
Frequency[Hz]
[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.
-8-