NJM2705
-1-
Surround Audio Processor for Mobile Applications
GENERAL DESCRIPTION
The NJM2705 is the surround audio processor for mobile
applications.
It regenerates the 3D surround sound with extremely narrow
space two speakers (2SP mode), headphone surround with
normal headphone (HP mode) and reverberation sound with
only one speaker (1SP mode).
It includes mode control switches for surround function and
standb y func tion and rea li zes lo w c ons umption po wer desig n by
standby function.
In addition to SSOP16, an ultra small and thin package
FFP16 (Flip-Chip Fine Package) is applied.
It is suitable for cellular phone, PDA and portable game.
FEA TURES
Operating Voltage 1.8 to 6V
Operating Current 0.7mA typ. at Active mode
1µA max. at Standby mode
Low Output Noise 10µVrms typ
(2SP/HP/1SP mode, VR : max.)
Variable Surround Effect by external resistor
(Adjustable for speaker and headphone independently.)
Standby Function
Internal Mode Control Switch
Bipolar Technology
Package Outline FFP16, SSOP16
BLOCK DIAGRAM
PACKAGE OUTLINE
NJM2705PC1 NJM2705V
3D
Filter
2SP mode
H P mode
1SP mode
By pass m ode
Su r roun d mode
3D
Enhancer
1SP
Surround
LIN
RIN
LOUT
ROUT
NJM2705
- 2 -
PIN CONFIGURATION
1. LIN 9. LMON
2. RIN 10. PS
3. LOUT 11. SW2
4. ROUT 12. SW1
5. NFSPR 13. STBY
6. NFHPR 14. V+
7. NFSPL 15. GND
8. NFHPL 16. VREF
15
13
14
6
8
7
1 2 3
11 10 9
4
5
12
16
14
12
13 4
6
5
1
2
3
11
10 7
16
15
9 8
FFP16
(
To
p
View
)
1. NFHPR 9. V+
2. NFSPR 10. STBY
3. ROUT 11. SW1
4. LOUT 12. SW2
5. RIN 13. PS
6. LIN 14. LMON
7. VREF 15. NFHPL
8. GND 16. NFSPL
SSOP16
(
To
p
View
)
NJM2705
-3-
ABSOLUTE MAXIMUM RATING (Ta=25°C)
PARAMETER SYMBOL RATINGS UNIT
Supply Voltage V
+
7 V
Power Dissipation P
D
(FFP16) 400
(SSOP16) 300 mW
Operating Temperature Range T
opr
-20 to +75 °C
Storage Temperature Range T
stg
-40 to +125 °C
OPERATING VOLTAGE
PARAMETER
SYMBOL
TEST CONDIT ION MIN TYP MAX UNIT
Operating Voltage V
+
- 1.8 3.0 6.0 V
ELECTRIC AL CH AR ACT ERI ST IC S (V+=3V, Ta=25°C unless otherwise specified)
TEST CONDIT ION
INPUT
PARAMETER
SYMBOL
L R
OUT
PUT MODE SP
VR
HP
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 CHARACTERISTICS
(V
+
=3V, Ta=25°C, V
IN
=-20dBV(100mVrms), f=1kHz, RL=10k, unless otherwise specified)
TEST CONDIT ION
INPUT
PARAMETER
SYMBOL
L R
OUT
PUT MODE SP
VR
HP
VR
MIN TYP MAX UNIT
V
IM1
f=1kHz
THD=1% V
IN
0 0
V
IN
L
R Bypass
- -
- -2.0
(790) -
V
IM2
f=100Hz
THD=1% V
IN
0 0
V
IN
L
R 2SP
MAX -
- -16.0
(160) -
V
IM3
f=100Hz
THD=1% V
IN
0 0
V
IN
L
R HP
- MAX
- -16.0
(160) -
V
IM4
f=100Hz
THD=1% V
IN
0 L 1SP
MAX -
- -16.0
(160) -
V
IM5
f=100Hz
THD=1% 0 V
IN
L 1SP
MAX -
- -14.5
(190) -
V
IM6
V
+
=1.8V,f=1kHz
THD=1% V
IN
0 0
V
IN
L
R Bypass
- -
-10.5
(300) -8.5
(380) -
V
IM7
V
+
=1.8V,f=100Hz
THD=1% V
IN
0 0
V
IN
L
R 2SP
MAX -
-24.5
(60) -22.5
(75) -
V
IM8
V
+
=1.8V,f=100Hz
THD=1% V
IN
0 0
V
IN
L
R HP
- MAX
-24.5
(60) -22.5
(75) -
V
IM9
V
+
=1.8V,f=100Hz
THD=1% V
IN
0 L 1SP
MAX -
-24.5
(60) -22.5
(75) -
Maximum
Input Voltage
V
IM10
V
+
=1.8V,f=100Hz
THD=1% 0 V
IN
L 1SP
MAX -
-23.0
(70) -21.0
(90) -
dBV
(mVrms)
V
NO1
Rg=0
A-Weighted 0 0 L
R Bypass
- -
- -112
(2.5) -106
(5.0)
V
NO2
Rg=0
A-Weighted 0 0 L
R 1SP
MAX -
- -100
(10) -94
(20)
V
NO3
Rg=0
A-Weighted 0 0 L
R HP
- MAX
- -100
(10) -94
(20)
Output Noise
V
NO4
Rg=0
A-Weighted 0 0 L 1SP
MAX -
- -100
(10) -94
(20)
dBV
(µVrms)
NJM2705
- 4 -
AC CHARACTERISTICS
(V
+
=3V, Ta=25°C, V
IN
=-20dBV(100mVrms), f=1kHz, RL=10k, unless otherwise specified)
TEST CONDIT ION
INPUT
PARAMETER
SYMBOL
L R
OUT
PUT MODE
SP
VR
HP
VR
MIN TYP MAX UNIT
THD1 f=1kHz V
IN
0 0
V
IN
L
R Bypass
- -
- 0.02 0.05
THD2 f=1kHz V
IN
0 0
V
IN
L
R 2SP
MAX -
- 0.1 0.5
THD3 f=1kHz V
IN
0 0
V
IN
L
R HP
- MAX
- 0.1 0.5
Total Harmonic
Distortion
THD4 f=1kHz V
IN
0 0
V
IN
L
R 1SP
MAX -
- 0.1 0.5
%
BYPASS Gain G
VBYP
f=1kHz V
IN
0 0
V
IN
L
R Bypass
- -
-1.0 0.0 1.0 dB
G
VSUR1
f=100Hz V
IN
0 0
V
IN
L
R 2SP
MAX -
12.5 14.5 16.5
G
VSUR2
f=100Hz V
IN
0 0
V
IN
L
R 2SP
MIN -
0.5 2.5 4.5
G
VSUR3
f=100Hz V
IN
0 0
V
IN
L
R HP
- MAX
12.5 14.5 16.5
G
VSUR4
f=100Hz V
IN
0 0
V
IN
L
R HP
- MIN
0.5 2.5 4.5
G
VSUR5
f=100Hz V
IN
0 L 1SP
MAX -
6.5 8.5 10.5
G
VSUR6
f=100Hz 0 V
IN
L 1SP
MAX -
2.0 4.0 6.0
G
VSUR7
f=100Hz V
IN
0 L 1SP
MIN -
-5.5 -3.5 -1.5
Surround Gain
G
VSUR8
f=100Hz 0 V
IN
L 1SP MIN - -12.0 -10.0 -8.0
dB
CONTROL CHARACTERISTICS (V
+
=3V, Ta=25°C unless otherwise specified)
PARAMETER
SYMBOL
TEST CONDIT ION MIN TYP MAX UNIT
V
IN
=High Level 1.2 - V
+
MODE Selec t
Control Voltage V
MODE
V
IN
=Low Level 0.0 - 0.3 V
SWITCH FUNCTION
SURROUND FUNCTION SW
MODE SW1 SW2 NOTES
Bypass L, OPEN L, OPEN Input Through
2SP mode L, OPEN H Surround mode for narrow space two speakers
HP mode H L, OPEN Surround mode for Headphone
1SP mode H H Surround mode for monaural speaker (Surround signal from LOUT)
STANDBY SW
MODE STBY NOTES
Standby L, open IC is non-active
Active H IC is active
NJM2705
-5-
TERMINAL DESCRIPTION
PIN No.
FFP16 SSOP16
SYMBOL FUNCTION EQUIVALENT CIRCUIT Voltage
1
2 5
6 LIN
RIN Lch Input
Rch Input
1.15V
3
4
9
4
3
14
LOUT
ROUT
LMON
Lch Output
Rch Output
Filter terminal
1.15V
5
6
7
8
2
1
16
15
NFSPR
NFHPR
NFSPL
NFHPL
Filter terminal
Filter terminal
Filter terminal
Filter terminal
1.15V
10 13 PS Filter terminal
1.15V
400
V+
100k
VREF
V+
400
6p
6p
V+ V+V+ V+
12k
20k
6p
V+ V+
400
20k
6p
V+ V+
400
20k
6p400
6p
NJM2705
- 6 -
TERMINAL DESCRIPTION
PIN No.
FFP16 SSOP16
SYMBOL FUNCTION EQUIVALENT CIRCUIT Voltage
11
12 12
11 SW2
SW1 Mode control switch
Mode control switch
0V
13 10 STBY Standby switch
0V
14 9 V+ Power Supply
V+
15 8 GND GND
0V
16 7 VREF Reference voltage
1.15V
700
275k
V+ V+V+
25k
3p
700
225k
V+ V+
75k
3p
300k
V+ V+V+
300k
400 400
6p
6p
NJM2705
-7-
APPLICATION CIRCUIT (FFP16)
1) 2SP mode, HP mode
2) 1SP mode, HP mode
Rc h IN
12
13
14
1
15
SW1
V+
VREF
GND
4.7k
2 3
11 10
8
7
6
SW2
ROUTLOUTRINLIN
HP VR
Lc h OUT
100k
V+
10µ
9
516
4
LMON
NFSP
R
NFHP
R
NFSPL
NFHPL
PS
STBY
100k
0.1µ
Lc h IN Rch O UT
0.027µ
0.0047µ
0.0033µ
SW1 SW2
STBY
4.7k
SP VR
MAX
MIN
50kB
MAX
MIN
50kB
0.1µ
0.0047µ
0.0033µ
Rc h IN
12
13
14
1
15
SW1
V+
VREF
GND
4.7k
2 3
11 10
8
7
6
SW2
ROUTLOUTRINLIN
HP VR
Lc h OUT
100k
V+
9
516
4
LMON
NFSP
R
NFHP
R
NFSPL
NFHPL
PS
STBY
100k
Lc h IN Rch O UT
SW1 SW2
STBY
4.7k
SP VR
MAX
MIN
50kB
MAX
MIN
50kB
10µ
0.1µ
0.027µ
0.0047µ
0.1µ
0.0047µ
0.0033µ
Surround signal is outputted from LOUT terminal at 1SP mode.
NJM2705
- 8 -
APPLICATION CIRCUIT (SSOP16)
1) 2SP mode, HP mode
2) 1SP mode, HP mode
Rch IN
Lc h O UT
Lc h IN
Rc h O UT
SW1
SW2
STBY
1
2
3
5
4
14
15
13
16
6
NFSPR
STBY
ROUT
SW1
LOUT
SW2RIN
PS
LIN
LMON
7
11
12
10
V+
NFHPL
VREF
HFHPR
8 9
NFSPL
GND
0.1µ
0.1µ
100k
100k
0.027µ
V+
10µ
0.004
0.0030.004
0.003
4.7k
50kBHP VR
MA
X
MIN
4.7k
50kBSP VR
MA
X
MIN
Rch IN
Lc h O UT
Lc h IN
Rc h O UT
SW1
SW2
STBY
1
2
3
5
4
14
15
13
16
6
NFSPR
STBY
ROUT
SW1
LOUT
SW2RIN
PS
LIN
LMON
7
11
12
10
V+
NFHPL
VREF
HFHPR
8 9
NFSPL
GND
0.
0.
100k
1µ
100k
0.027µ
V+
10µ
0.004
0.0030.0047µ
4.7k
50kBHP VR
MA
X
MIN
4.7k
50kBSP VR
MA
X
MIN
Surround signal is outputted from LOUT terminal at 1SP mode.
NJM2705
-9-
TYPICAL CHARACTERISTICS
0
0.2
0.4
0.6
0.8
1
01234567
Operating Current vs. Operating Voltage (STANDBY)
O perati ng Current A]
O perating V oltage [V ]
Ta=25
o
C
0
5
10
15
20
-50 -25 0 25 50 75 100 125
Ope ratin g Current vs . Tempera ture (STANDBY)
O per a ting Curr ent [µA]
Ta [
o
C]
V+=3V
0
200
400
600
800
1000
01234567
Operating Cur rent vs. Oper ating Voltage (ACT IVE)
Operat ing Current [µA]
O per ating Voltage [ V]
Ta=25
o
C
Bypa ss,2SP,HP,1SP mode
0
200
400
600
800
1000
-50 -25 0 25 50 75 100 125
Operating Current vs. T emperature (ACT IVE)
O p erati ng Current [µA]
Ta [
o
C]
V+=3V
Bypa s s,2 S P, HP,1SP mo de
0
0.5
1
1.5
2
2.5
3
3.5
01234567
Reference Voltage vs. Operating Voltage
Reference Voltag e [V]
Operatin g Volt age [ V]
Ta=25
o
C
1
1.05
1.1
1.15
1.2
1.25
1.3
-50 -25 0 25 50 75 100 125
Reference Voltage vs. Temper ature
Refere nce Vo ltage [ V ]
Ta [
o
C]
V+=3V
NJM2705
- 10 -
TYPICAL CHARACTERISTICS
-15
-10
-5
0
5
10
01234567
Maximum Inpu t V oltage vs. Operating V oltage (BYPASS)
M a x im um Input V ol tage [ d B V ]
Operating Volt age [V]
f= 1kHz, RL=10k, THD= 1 %, T a =2 5
o
C
Vin=Lch Vout=Lch
Vin=Rch Vout=Rch
-30
-25
-20
-15
-10
-5
01234567
M aximum Inpu t Voltage vs. Oper ating Voltage (2SP)
Ma x imu m In pu t Vol ta g e [d BV ]
Oper ating Voltage [V ]
Ta= 25
o
C, f =100Hz SP_VR=MAX, RL=10kΩ, THD=1%
Vin=Lch Vou t=Lch
Vin=Rch Vout=Rch
-30
-25
-20
-15
-10
-5
01234567
Maximum Input Voltage vs. Operating Voltage (HP)
Max imum In pu t V ol tage [d BV ]
Operating Voltage [V ]
Ta=25
o
C, f= 1 00H z, HP _V R=MAX, R L=10k,THD=1%
Vin=Lch Vou t=Lch
Vin=Rch Vout=Rch
-30
-25
-20
-15
-10
-5
01234567
Maximum Input Volta ge vs. T e mperature (1S P)
Maximu m In pu t Vol tag e [dBV]
O perating Voltage [ V ]
Ta= 25
o
C, f=100Hz, SP_VR=MAX, RL=10k, TH D=1 %
Vin=Lch Vout=Lch
Vin=Rch Vout=Lch
-20
-19
-18
-17
-16
-15
-50 -25 0 25 50 75 100 125
Maximum Input Voltage vs. Temperature (2SP)
Ma ximu m In pu t Volta ge [dBV ]
Ta [
o
C]
V+=3V, f=100Hz, RL=10 k
SP_VR=MAX, THD=1%
Vin = Lch Vout=Lch
Vin=Rch Vou t=Rch
-5
-4
-3
-2
-1
0
-50 -25 0 25 50 75 100 125
Maximum Input Voltage vs . Tem perature (B YPASS)
Ma x imu m In pu t Vol ta g e [d BV]
Ta [
o
C]
V+=3V, f=1kHz, RL= 10k
THD=1%
V in=Lc h V out=Lc h
Vin=Rch Vou t=R c h
NJM2705
-11-
TYPICAL CHARACTERISTICS
-20
-19
-18
-17
-16
-15
-50 -25 0 25 50 75 100 125
Maximum Input Volta ge vs. Tem perrature (HP)
Ma ximu m Inpu t Voltag e [dBV]
Ta [
o
C]
V+=3V, f=100Hz, RL=10 k
HP_VR=MAX, THD=1%
V in=Lch Vout= Lch
Vin=Rch Vout=Rch
-17
-16
-15
-14
-13
-12
-50 -25 0 25 50 75 100 125
Maximum Inpu t V oltage vs. Tem perature (1SP)
Ma ximu m In put Volta ge [d BV]
Ta [
o
C]
V+=3 V, f=100 Hz, RL=10k
SP_VR=MAX , THD=1%
Vin=Rch Vout=Lch
Vin=Lch Vout=Lch
-120
-115
-110
-105
-100
-95
-90
-50 -25 0 25 50 75 100 125
Out put Noise Voltage vs. Temperature
O utput Noise Vo ltage [d BV]
Ta [
o
C]
V+=3V, Rg=0, V out= L ch
SP _ VR=M AX, HP_ VR= MAX, F ILT ER=A-Weigh te d
Bypass
2SP mode
HP mode
1SP mode
-120
-115
-110
-105
-100
-95
-90
-50 -25 0 25 50 75 100 125
Out put Noise Voltage vs . Temperature
O u tput No ise Voltage [d BV]
Ta [
o
C]
V+=3V, Rg=0, V ou t=Rch
SP_VR=MAX, HP_VR=MAX, FILT ER=A-Weighte d
Bypass
2SP mode
HP mode
0.001
0.01
0.1
1
10
-50 -40 -30 -20 -10 0
Total Har mo nic Di sto rt ion vs. Inpu t Voltage (BYPASS)
THD+N [%]
I nput Volt ag e [d B V ]
V+ =3V, V in=Lch, f=1kHz , Vout=Lc h
RL=10k, BW=10Hz-80kHz
Ta=75
o
C
Ta=25
o
C
Ta=-20
o
C
0.01
0.1
1
10
-50 -40 -30 -20 -10 0
Total Har mo nic Disto rtion v s. Input Vo l tage (2SP)
TH D +N [% ]
Input Vo ltage [dBV]
V+=3 V , Vin =Lch, f=1 00H z, Vou t=Lc h
RL=10k, BW =10 Hz-80 kHz, SP_ VR=MAX
Ta=75
o
C
Ta=25
o
C
Ta=-20
o
C
NJM2705
- 12 -
TYPICAL CHARACTERISTICS
0.01
0.1
1
10
-50 -40 -30 -20 -10 0
Total Harmonic Distortion v s. Input Voltage (HP )
TH D+ N [%]
I npu t Voltage [d B V]
V+=3V, Vin=Lch, f=100Hz, Vout=Lch
RL=10k, BW =10 Hz- 80kHz, H P_VR=MAX
Ta=75
o
C
Ta=25
o
C
Ta=-20
o
C
0.01
0.1
1
10
-50 -40 -30 -20 -10 0
Total Harmonic Distortion vs. Input Voltage (1 SP)
TH D + N [% ]
I nput Voltag e [dBV ]
V+ = 3V, Vi n=Lc h, f=100Hz, V out=Lch
RL=10k, BW =10 Hz- 80kHz, S P_VR=MAX
Ta=75
o
C
Ta=25
o
C
Ta=-20
o
C
-1
-0.5
0
0.5
1
10 100 1000 10
4
10
5
Frequency Responce (BYPASS)
Ga i n [d B]
Frequency [Hz]
V+=3V, Vin =- 20dBV L ch, Vo ut= Lch
RL=10k, Rg = 2 5
Ta=-20,25,75
o
C
-5
0
5
10
15
20
10 100 1000 10
4
10
5
Frequency Responce (2SP)
Ga in [d B]
Frequency [Hz]
V+=3V, Vi n=-2 0d BV Lch, Vou t=L ch
RL=10k, Rg =2 5 , SP_V R=MAX
Ta=-20
o
C
Ta=25
o
C
Ta=75
o
C
-5
0
5
10
15
20
10 100 1000 10
4
10
5
Frequency Responce (2SP)
Ga in [d B ]
F r equency [H z ]
V+= 3V, V in=- 2 0d BV Lch , Vou t=L c h
RL=10k, Rg = 2 5 , SP_ VR= MI N
Ta=-20
o
C
Ta=25
o
C
Ta=75
o
C
-270
-180
-90
0
90
10 100 1000 10
4
10
5
Phase vs. Freq u ency (2SP )
Pha se [dB]
F r equency [H z ]
V +=3V, V in=- 20dBV, Lch+Rch
RL=10kΩ, Rg=25Ω, SP_VR=MAX
Ta=-20,25,75
o
C
Vout=Rch
Ta=-20,25,75
o
C
Vout=Lch
NJM2705
-13-
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
10 100 1000 10
4
10
5
Frequency Respo nce (HP)
Ga i n [d B]
F r equenc y [Hz]
V+= 3 V, Vin =-20dB V L ch, Vo ut =Lch
RL=10k, Rg= 2 5 , HP_V R=MAX
Ta=-20
o
C
Ta=25
o
C
Ta=75
o
C
-5
0
5
10
15
20
10 100 1000 10
4
10
5
Freque ncy Resp once (HP)
Gai n [d B]
Freque ncy [H z]
V+=3V, Vin=-20dBV Lch, Vout=L ch
RL=10k, Rg = 2 5, HP_ VR= MIN
Ta=-20
o
C
Ta=25
o
C
Ta=75
o
C
-10
-5
0
5
10
15
10 100 1000 10
4
10
5
Frequency Responc e ( 1S P)
Gai n [dB]
F r equenc y [Hz]
V+=3V, Vin =- 20dB V , Vou t=Lch
RL=10k, Rg =2 5, S P_ V R = MAX
Ta=-20
o
C
Ta=25
o
C
Vin=RchTa=75
o
C
Ta=-20
o
C
Ta=25
o
C
Ta=75
o
C
Vin=Lch
-15
-10
-5
0
5
10
10 100 1000 10
4
10
5
Frequency Responce (1SP)
Gai n [dB]
Freque ncy [H z]
V+=3V, Vin=-20dB V, Vout=L ch
RL=10k,Rg=25, VR=M IN
Ta=-20
o
C
Ta=25
o
C
Vin=Rch
Ta=75
o
C
Ta=-20
o
C
Ta=25
o
C
Ta=75
o
CVin=Lch