NJM2704
-1-
3D SURROUND AUDIO PROCESSOR FOR HEADPHONE
■
■■
■ GENERAL DESCRIPTION
The NJM2704 is a high quality 3D surround audio processor
designed for headphone applications.
It includes mode control switches for surround function and
standb y func tion and realizes lo w cons umption po wer des ig n by
standby function.
It is suitable for portable telephone, PDA and any portable
audio applications.
■
■■
■ FEATURES
● Operating Voltage 1.8 to 6V
● Low Operating Current 0.45mA typ. (at Active mode)
0.1µA typ. (at Standby mode)
● Low Output Noise 10µV typ. (at Surrou nd m ode, VR: m ax .)
● Variable Surrou nd Ef f ect by externa l resistor
● Internal Mode Control Switch
● Bipolar Technology
● Package Outline SSOP14
■
■■
■ PIN CONFIGURATION
■
■■
■ PACKAGE OUTLINE
NJM2704V
12
10
11
4
6
5
1
2
3
9
8
7
14
13
1. STANDBY SW
2. LIN
3. RIN
4. MODE SW
5. VREF
6. GND
7. NC
8. DNC
9. V+
10. NFR
11. NFL
12. ROUT
13. LOUT
14. NC
NJM2704
- 2 -
■
■■
■ BLOCK DIAGRAM
3D
FILTER
STEREO
BYPASS
3D
FILTER
STEREO
BYPASS
BIAS
V+
GND
VREF MODE SW RIN
LIN
LOUT
ROUTNFLNFR
STANDBY SW
TP
NJM2704
-3-
■
■■
■ABSOLUTE MAXIMUM RATING (Ta=25°C)
PARAMETER SYMBOL RATINGS UNIT
Suppl y Voltag e V
+
7 V
Power Dissipation P
D
320 mW
Operating Temperature Range T
opr
-20 to +75 °C
Storage Temperature Range T
stg
-40 to +125 °C
■
■■
■OPER ATING VO L TAGE
PARAMETER SYMBOL
TEST CONDITION
MIN. TYP. MAX. UNIT
Operating
Voltage V+
-
1.8 3.0 6.0 V
■
■■
■ELECTRICAL CHARACTERISTICS (V+=3V, Ta=25°C unless otherwise specified)
TEST CONDITION
INPUT
PARAMETER SYMBOL L R OUTPUT MODE VR
MIN. TYP. MAX. UNIT
0 0 - Active - - 450 700
Operating
Current I
CC
No Signal 0 0 - Standby - - 0.1 1.0
µA
Reference
Voltage Vref No Signal 0 0 - - - 1.0 1.15 1.3 V
●AC CHARAC TER ISTIC S
(V+=3V, Ta=25°C, V
IN
=-20dBV(100mVrms), f=1kHz, RL=10kΩ, unless otherwise specified)
TEST CONDITION
INPUT
PARAMETER SYMBOL
L R OUTPUT MODE VR
MIN. TYP. MAX. UNIT
f=1kHz
T.H.D.=1% V
IN
0 0
V
IN
L
R Bypass - - -2.0
(790) -
f=100Hz
T.H.D.=1% V
IN
0 0
V
IN
L
R Surround MAX - -16.0
(160) -
V+=1.8V
f=1kHz
T.H.D.=1%
V
IN
0 0
V
IN
L
R Bypass - -10.5
(300) -8.5
(380) -
Maximum
Input Voltage V
IM
V+=1.8V
f=100Hz
T.H.D.=1%
V
IN
0 0
V
IN
L
R Surround MAX -24.5
(60) -22.5
(75) -
dBV
(mVrms)
Rg=0
Ω
A-Weighted 0 0 L
R Bypass - -
-112
(2.5) -106
(5.0)
Output Noise V
NO
Rg=0
Ω
A-Weighted 0 0 L
R Surround MAX - -100
(10) -94
(20)
dBV
(µVrms)
f=1kHz V
IN
0 0
V
IN
L
R Bypass - - 0.02 0.05
Total
Harmonic
Distortion
T.H.D
f=1kHz V
IN
0 0
V
IN
L
R Surround MAX - 0.1 0.5
%
NJM2704
- 4 -
●AC CHARAC TER ISTIC S
(V+=3V, Ta=25°C, V
IN
=-20dBV(100mVrms), f=1kHz, RL=10kΩ, unless otherwise specified)
TEST CONDITION
INPUT
PARAMETER SYMBOL L R OUTPUT MODE VR
MIN. TYP. MAX. UNIT
Bypass Gain G
VBYP
f=1kHz V
IN
0 0
V
IN
L
R Bypass - -1.0 0.0 1.0 dB
f=100Hz V
IN
0 0
V
IN
L
R Surround MAX 12.5 14.5 16.5
f=100Hz 0
V
IN
V
IN
0 L
R Surround MAX 10.5 12.5 14.5
Surround Gain G
VSUR
f=100Hz V
IN
0 0
V
IN
L
R Surround MIN 0.5 2.5 4.5
dB
●
●●
●CONTROL CHARACTERISTICS (V+=3V, Ta=25°C unless otherwise specified)
TEST CONDITION
INPUT
PARAMETER SYMBOL L R OUTPUT MODE VR
MIN. TYP. MAX. UNIT
V
IN
=
High Level - - - - - 1.2 - V+
Mode Select
Control
Voltage V
MODE
V
IN
=
Low Level - - - - - 0.0 - 0.3 V
■
■■
■SWITCH FUNCTION
MODE SW
MODE Terminal Status NOTES
Bypass L, open Input Through
Surround H Surround Mode (Stereo Input)
STANDBY SW
MODE Terminal Status NOTES
Standby L, open IC is non-active
Active H IC is active
NJM2704
-5-
■
■■
■TERMINAL DESCRIPTION
PIN No. SYMBOL FUNCTION EQUIVALENT CIRCUIT Voltage
1 STANDBY
SW Standby switch
0V
2
3 LIN
RIN Lch Input
Rch Input
1.15V
4 MODE SW Mode control switch
0V
5 VREF Reference voltage
1.15V
300k
V+ V+V+
300k
V+
700
225k
V+
75k
700
V+ V+
100k
VREF
V+
700
300k
V+ V+V+
NJM2704
- 6 -
PIN No. SYMBOL FUNCTION EQUIVALENT CIRCUIT Voltage
6 GND GND
0V
7
14 NC No Connect
-
8 DNC Do Not Connect
-
9 V+ Power Supply
V+
10
11 NFR
NFL Filter terminal
Filter terminal
1.15V
12
13 ROUT
LOUT Rch Output
Lch Output
1.15V
V+ V+V+ V+
12k
20k
V+ V+
400
20k
NJM2704
-7-
■
■■
■APPLICAT ION CIRCUIT
1
2
3
5
4
12
13
11
14
6
Lch IN
Rch IN
0.0047u
0.0047u
4.7k
LIN LOUT
RIN ROUT
MODE
SW NFL
VREF NFR
GND V+
1u
MODE SW 100k
V+
10u
7
9
10
8
NC STANDBY SW
DNC NC
1u MAX
MIN
50kB
VR
Lch OUT
Rch OUT
STANDBY
SW
0.1u
0.1u
NJM2704
- 8 -
■
■■
■TYPICAL CHARACTERISTICS
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
01234567
Suppl y Current vs. Supply Voltage
Supply Current [mA]
Supply Voltage [V]
Ta=25degrees
BYPASS
Surround
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
-50-250 255075100125
Supply Current vs. Ambient Temperature
Supply Current [mA]
Ambient Temperature [degrees]
V+=3V
BYPASS
Surround
0
0.5
1
1.5
2
2.5
3
3.5
01234567
Reference Voltage vs. Supply Voltage
Reference Voltage [V]
Supply Voltage [V]
Ta=25degrees
-15
-10
-5
0
5
10
01234567
Maximum Input Voltage vs. Supply Voltage (BYPASS)
Maximum Input Voltage [dBV]
Supply Voltage [V]
Vin=Lch f=1kHz Vout=Lch RL=10kohm
THD=1% Ta=25degrees
-30
-25
-20
-15
-10
-5
01234567
Maximum Input Voltage vs. Supply Voltage (Surround)
Maximum Input Voltage [dBV]
Supply Voltage [V]
Vin=Lch f=100Hz Vout=Lch RL=10kohm VR=MAX
THD=1% Ta=25degrees
1
1.05
1.1
1.15
1.2
1.25
1.3
-50-250 255075100125
Reference Voltage vs. Ambient Temperature
Reference Voltage [V]
Ambient Temperature [degrees]
V+=3V
NJM2704
-9-
■
■■
■TYPICAL CHARACTERISTICS
-5
-4
-3
-2
-1
0
-50-250 255075100125
Maximum Input Voltage vs. Ambient Temperature (BYPASS)
Maximum Input Voltage [dBV]
Ambient Temperature [degrees]
V+=3V Vin=Lch f=1kHz Vout=Lch RL=10kohm
THD=1%
-20
-19
-18
-17
-16
-15
-50-250 255075100125
Maxim um Input Voltage vs . Ambient Temper ature (Sur r ound)
Maximum Input Voltage [dBV]
Ambient Temperature [degrees]
V+=3V Vin=Lch f=100Hz Vout=Lch RL=10kohm
VR=MAX THD=1%
-10
-9
-8
-7
-6
-5
-50-250 255075100125
Maximum Input Voltage vs. Ambient Temperature (BYPASS)
Maximum Input Voltage [dBV]
Ambient Temperature [degrees]
V+=1.8V Vin=Lch f=1kHz Vou t=Lch RL=10kohm
THD=1%
-25
-24
-23
-22
-21
-20
-50-250 255075100125
Maxim um Input Voltage vs . Ambient Temper ature (Sur r ound)
Maximum Input Voltage [dBV]
Ambient Temperature [degrees]
V+=1.8 V Vin=Lch f=100Hz Vout=Lch RL=10kohm
VR=MAX THD=1%
-120
-115
-110
-105
-100
-95
-90
-50-250 255075100125
Output Noise Voltage vs. Am bient Temperature
Output Noise Voltage [dBV]
Ambient Temperature [degrees]
V+=3V Rg=0ohm Vout=Lch VR=MAX
FILTER=A-Weighted
BYPASS
Surround
-120
-115
-110
-105
-100
-95
-90
-50-250 255075100125
Output Noise Voltage vs. Am bient Temperature
Output Noise Voltage [dBV]
Ambient Temperature [degrees]
V+=3V Rg=0ohm Vout=Rch VR=MAX
FILTER=A-Weighted
BYPASS
Surround
NJM2704
- 10 -
■
■■
■TYPICAL CHARACTERISTICS
0.001
0.01
0.1
1
10
-50 -40 -30 -20 -10 0 10
Total Harmonic Distortion vs. Input Voltage (BYPASS)
THD+N [%]
Inp u t Vo ltag e [dB V ]
V+=3V Vin=Lch f=1kHz Vout=Lch
RL=10kohm BW=10Hz to 80kHz
Ta=75deg.
Ta=25deg.
Ta=-20deg.
0.01
0.1
1
10
-50 -40 -30 -20 -10 0
Total Harmonic Distortion vs. Input Voltage (Surround)
THD+N [%]
Inp u t Vo ltag e [dB V ]
V+=3V Vin=Lch f=100Hz Vout=Lch
RL=10kohm BW=10Hz to 80kHz VR=MAX
Ta=75deg.
Ta=25deg.
Ta=-20deg.
-1
-0.5
0
0.5
1
10 100 1000 10
4
10
5
Voltage Gain vs. Frequency (BYPASS)
Vo ltage Gain [dB]
Frequency [Hz]
V+=3V Vin = -20dBV Lch Vout=Lch
RL=10kohm Rg=25ohm
Ta=-20deg.
Ta=25deg.
Ta=75deg.
-5
0
5
10
15
20
10 100 1000 10
4
10
5
Voltage Gain vs. Frequency (Surround)
Vo ltage Gain [dB]
Frequency [Hz]
V+=3V Vin=-20dBV Lch Vout=Lch
RL=10kohm Rg=25ohm VR=MAX
Ta=-20deg.
Ta=25deg.
Ta=75deg.
-10
-5
0
5
10
15
10 100 1000 10
4
10
5
Voltage Gain vs. Frequency (Surround)
Vo ltage Gain [dB]
Frequency [Hz]
V+= 3V Vin=-20dBV Rch Vout=Lch
RL=10kohm Rg=25ohm VR=MAX
Ta=-20deg.
Ta=25deg.
Ta=75deg.
-5
0
5
10
15
20
10 100 1000 10
4
10
5
Voltage Gain vs. Frequency (Surround)
Vo ltage Gain [dB]
Frequency [Hz]
V+=3V Vin=-20dBV Lch Vout=Lch
RL=10kohm Rg=25ohm VR=MIN
Ta=-20deg.
Ta=25deg.
Ta=75deg.
NJM2704
-11-
■
■■
■TYPICAL CHARACTERISTICS
[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.
-5
0
5
10
15
20
00.511.52
Voltage Gain vs. SW Terminal Input Voltage
Vo ltage Gain [dB]
SW Terminal Input Voltage [V]
V+=3V Vin=-20dBV Lch f=100Hz Vout=Lch VR=MAX
BYPASS to Surround
Ta=25deg.
Ta=-20deg.
Ta=75deg.
-10
-5
0
5
10
-50-250 255075100125
Output DC Offset Voltage vs. Ambient Temperature
Output DC Offset Voltage [mV]
Ambient Temperature [degrees]
V+=3V
BYPASS to Surround
Rch
Lch
