MITSUMI
IC for Headphone Stereos LAG673
IC for Headphone Stereos
Monolithic IC LAG673
Outline
This IC was developed for use in 3 V headphone stereos. It incorporates dual preamp, power amp, electronic
volume and motor control circuits; because it requires extremely few external components, it can be used in a
simple circuit configuration.
Features
1. Broad operating voltage range of 2.0 to 5.0 V
2. Few external components required
3. Well-balanced electronic VR, A-curve attenuation characteristic obtained with B-curve VR
4. Internal motor control circuit, with noise from motor driving unit suppressed
5. Fast forward possible using the forced-on pin
Package
SOP-28B (LAG673F)
SDIP-30A (LAG673D)
Absolute Maximum Ratings
Item
Operating temperature
Storage temperature
Power supply current
Operating voltage
Power consumption
Symbol
T
OPR
T
STG
V
CC
Vop
Pd
Ratings
-20~+65
-40~+125
-0.3~+7.5
2.0~5.0
450 (SOP-28B)
750 (SDIP-30A)
Units
°
C
°
C
V
V
mW
MITSUMI
IC for Headphone Stereos LAG673
Electrical Characteristics
(Except where noted otherwise, Ta=25
°
C)
Symbol
I
CC
Measurement conditions
V
IN
=0V, I
M
=0mA
Min. Typ. Max. Units
18
25
mA
Item
Consumption current
(excluding motor speed controller unit)
Preamp unit (Ta=25
°
C)
Open-circuit gain
Closed-circuit gain
Maximum output voltage
Total harmonic distortion ratio
Output noise voltage
Input impedance
Crosstalk between channels
Output voltage with preamp off
Output resistance with preamp off
Input resistance with preamp off
Attenuator unit (Ta=25
°
C)
Maximum input voltage
Maximum attenuation
Attenuation error
Input impedance
Control pin input resistance
Power amp unit (Ta=25
°
C)
Voltage gain
Voltage gain difference between channels
Maximum output power
I
Maximum output power
II
Total harmonic distortion ratio
Crosstalk between channels
Output noise voltage
Ripple rejection
Noise of preamp + power amp
Motor control unit (Ta=25
°
C)
Consumption current
Startup current
Reference voltage
Reference voltage fluctuation
I
Reference voltage fluctuation
II
Reference voltage fluctuation
III
Current coefficient
Gvo
Gvc
Vom
THD
Vno
Zin
C·T
Vooff
Rooff
Rioff
Vi max.
Va max.
Vaerr
Zia
Zicot
Gv
Gv
Pom
Pom
THD
C·T
Vn
RR
Vnto
IMC
IMS
Vref
Vref1
Vref2
Vref3
K
Vo=-10dBm, R
L
=∞
Vo=-10dBm
40
THD=10%
0.30
V
OUT
=400mVrms
V
IN
=0V, Rg=2.2kΩ, BPF=30Hz~20kHz
V
OUT
=-10dBm
18
Rg=2.2kΩ, V
OUT
=-10dBm
30
V
IN
=100mVrms
72
42
0.45
0.05
150
22
10
10
0.2
66
15
0
20
100
28
0
28
0.2
55
0.25
50
6
3.0
Between RML-ADJ pins
V
CC
between 2.0 and 5.0V
I
M
between 25 and 250 mA
Ta between -10 and 50
°
C
V
RL
K=-------------
R
1
I
M
V
CC
between 2.0 and 6.5 V
I
M
between 25 and 250 mA
Ta between -10 and 60
°
C
T
M
=200mA
500
0.72
0.80
0.05
0.01
0.01
38
0.5
0.05
0.02
5.6
33
dB
44
dB
Vrms
0.5
%
300 µVrms
kΩ
dB
-50
dB
kΩ
kΩ
Vrms
dB
dB
kΩ
kΩ
dB
dB
mW
mW
2.0
%
dB
1.0 mVrms
dB
9 mVrms
mA
mA
0.87
V
%/V
%/mA
%/
°
C
43
%/V
%/mA
%/
°
C
0.6
V
kΩ
200
µA
kΩ
5.0
30
3
Vcont=min.
Vcont=max.
P
OUT
=5mW
Vcont=max.
THD=10%, R
L
=32Ω
THD=10%, R
L
=16Ω
P
OUT
=5mW
P
OUT
=5mW
Rg=2.2kΩ, Vcont=min.
100Hz, 100mVp-p
V
IN
=0V, Rg=2.2kΩ, Vcont=max.
26
20
30
45
42
*
32
Current coefficient fluctuation
I
K1
Current coefficient fluctuation
II
K2
Current coefficient fluctuation
III
K3
Output voltage on forced on
VCEsa
Input resistance on forced on
Rion
Leakage current on forced off
IML
Ricon
Input resistance on forced off
Conditions: V
CC
=3.0 V, I
M
= 100 mA Motor: M25E-7 (Mitsumi model)
Voltage drift between pins 17 and 13
*
MITSUMI
IC for Headphone Stereos LAG673
Block Diagram
1: The motor speed potentiometer is 1.5 kΩ (assuming the motor used is Mitsumi M25E-7; if the optimal
adjustment range is not obtained using a different motor, add a fixed resistance).
2: RML = motor load correction resistance
3: Connecting the preamp off pin to +V
CC
turns the preamp circuits off.
4: Connecting the motor forced-on pin to +V
CC
turns the motor on (no control).
5: in circles are pin numbers for a DIP-30P package; numbers in parentheses (
) are for an SOP-28B
package.
6: In the DIP-30P package, pins 15 and 16 are NC.
7: Ca is a 100,000 pF capacitor used to prevent oscillation of the 1/2 V
CC
amp circuit.
MITSUMI
IC for Headphone Stereos LAG673
Characteristics
Output voltage attenuation (dB)
Preamp
THD-V
OUT
Attenuator
V
ATT
-V
CONT
0
-20
-40
-60
-80
0/6 1/6
(min.)
2/6
3/6
4/6
5/6
6/6
(max.)
V
CC
=3.0V
Total harmonic distortion ratio (%)
V
CC
=1.8V
V
CC
=2.0V
V
CC
=3.0V
10.0
1.0
0.1
Voltage controllability
(B curve mechanical volume knob)
0.01
-30
-20
-10
0
Output voltage (dBm)
P
OUT.
Power supply output
(THD=10%) P
OUT
max. (mW)
I
CC
-V
CC
70
60
50
40
30
20
10
0
1.0
I
OC
(R
L
=16Ω)
R
L
=16Ω
R
L
=32Ω
10
5
20
15
No-load consumption current (mA)
Power amp
100
THD-P
OUT
Total harmonic
distortion ratio (%)
V
CC
=1.8V
V
CC
=2.0V
10
V
CC
=3.0V
1
2.0
3.0
4.0
5.0
0.1
0.1
1
10
100
Power supply voltage (V)
Power supply output (mW)
Power amp
Ripple rejection rate-V
CC
Power amp
Crosstalk frequency
PREAMP OFF
V
R
=max.
F
R
=100Hz
V
R
=100mVrms
R
L
=16Ω
-10
-20
-30
-40
-50
100
1k
10k
100k
V
CC
=3.0V
Ripple rejection (V)
-20
-30
-40
-50
0
1.0
2.0
3.0
4.0
5.0
Power supply voltage (dB)
Crosstalk (dB)
-10
Frequency (Hz)
Voltage gain vs. Frequency
100
80
70
60
50
40
30
20
10
10
100
V
CC
=3.0V
When V
R
=max.
TOTAL GAIN
Gain (dB)
POWER AMP GAIN
1k
10k
100k
Frequency (Hz)
京公网安备 11010802033920号
EEWORLD
