Datasheet

MAX9725
1V, Low-Power, DirectDrive, Stereo Headphone
Amplifier with Shutdown
6 _______________________________________________________________________________________
0
10
20
30
40
50
60
70
80
0 1020304050
POWER DISSIPATION
vs. OUTPUT POWER
MAX9725 toc16
OUTPUT POWER (mW)
POWER DISSIPATION (mW)
V
DD
= 1.5V
f
IN
= 1kHz
P
OUT
= P
OUTL
+ P
OUTR
OUTPUTS IN-PHASE
R
L
= 16Ω
R
L
= 32Ω
0
5
10
15
20
25
30
35
0 5 10 15 20
POWER DISSIPATION
vs. OUTPUT POWER
MAX9725 toc17
OUTPUT POWER (mW)
POWER DISSIPATION (mW)
V
DD
= 1V
f
IN
= 1kHz
P
OUT
= P
OUTL
+ P
OUTR
OUTPUTS IN-PHASE
R
L
= 16Ω
R
L
= 32Ω
10 100 10k1k 100k
GAIN FLATNESS
vs. FREQUENCY
FREQUENCY (Hz)
AMPLITUDE (dB)
2
1
0
-1
-2
-3
-4
-5
-7
-6
-8
-9
-10
MAX9725 toc18
0
5
10
15
20
25
30
35
40
10 20 30 40 50
OUTPUT POWER vs. CHARGE-PUMP
CAPACITANCE AND LOAD RESISTANCE
MAX9725 toc19
LOAD RESISTANCE (Ω)
OUTPUT POWER (mW)
V
DD
= 1.5V
f
IN
= 1kHz
THD+N = 1%
C1 = C2 = 2.2μF
C1 = C2 = 1μF
C1 = C2 = 0.47μF
C1 = C2 = 0.68μF
-160
-140
-120
-100
-80
-60
-40
-20
0
0 5 10 15 20
OUTPUT SPECTRUM
vs. FREQUENCY
MAX9725 toc20
FREQUENCY (kHz)
AMPLITUDE (dB)
f
IN
= 1kHz
R
L
= 32Ω
V
OUT
= -60dBV
V
DD
= 1.5V
0
1.5
1.0
0.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
0.9 1.11.0 1.2 1.3 1.4 1.5
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX9725 toc21
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
NO LOAD
Typical Operating Characteristics (continued)
(V
DD
= 1.5V, V
PGND
= V
SGND
= 0V, V
SHDN
= 1.5V, V
SS
= V
PVSS,
C1 = C2 = 1µF, C
IN
= 1µF, THD+N measurement bandwidth = 22Hz
to 22kHz, T
A
= +25°C, unless otherwise noted.) (See the Functional Diagrams. )
0
15
10
5
20
25
30
35
40
45
50
0.9 1.1 1.3 1.5
OUTPUT POWER
vs. SUPPLY VOLTAGE
MAX9725 toc13
SUPPLY VOLTAGE (V)
OUTPUT POWER (mW)
f
IN
= 1kHz
R
L
= 32Ω
BOTH INPUTS
DRIVEN IN-PHASE
THD+N = 10%
THD+N = 1%
80
70
0
10 100 1k
OUTPUT POWER
vs. LOAD RESISTANCE
20
MAX9725 toc14
LOAD RESISTANCE (Ω)
OUTPUT POWER (mW)
40
60
10
30
50
V
DD
= 1.5V
f
IN
= 1kHz
BOTH INPUTS
DRIVEN IN-PHASE
THD+N = 10%
THD+N = 1%
80
70
0
10 100 1k
OUTPUT POWER
vs. LOAD RESISTANCE
20
MAX9725 toc15
LOAD RESISTANCE (Ω)
OUTPUT POWER (mW)
40
60
10
30
50
V
DD
= 1V
f
IN
= 1kHz
BOTH INPUTS
DRIVEN IN-PHASE
THD+N = 10%
THD+N = 1%