MAX9725
1V, Low-Power, DirectDrive, Stereo Headphone
Amplifier with Shutdown
4 _______________________________________________________________________________________
Note 1: All specifications are 100% tested at T
A
= +25°C; temperature limits are guaranteed by design.
Note 2: Input leakage current measurements limited by automated test equipment.
Note 3: f
IN
= 1kHz, T
A
= +25°C, THD+N < 1%, both channels driven in-phase.
Note 4: Testing performed with 32Ω resistive load connected to outputs. Mode transitions controlled by SHDN. K
CP
level calculated
as 20 log [peak voltage under normal operation at rated power level / peak voltage during mode transition]. Inputs are AC-
grounded.
Note 5: Using existing resistors with 1% precision.
Note 6: R
IN
= 10Ω, R
F
=10kΩ.
Typical Operating Characteristics
(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.
)
10 10k1k100 100k
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCY
MAX9725 toc01
FREQUENCY (Hz)
THD+N (%)
1
0.1
0.001
0.01
V
DD
= 1.5V
R
L
= 16Ω
A
V
= -2V/V
P
OUT
= 15mW
P
OUT
= 2mW
10 10k1k100 100k
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCY
MAX9725 toc02
FREQUENCY (Hz)
THD+N (%)
1
0.1
0.001
0.01
V
DD
= 1.5V
R
L
= 32Ω
A
V
= -2V/V
P
OUT
= 12mW
P
OUT
= 2mW
10 10k1k100 100k
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCY
MAX9725 toc03
FREQUENCY (Hz)
THD+N (%)
1
0.1
0.001
0.01
V
DD
= 1V
R
L
= 16Ω
A
V
= -2V/V
P
OUT
= 0.7mW
P
OUT
= 4mW
ELECTRICAL CHARACTERISTICS (MAX9725E) (continued)
(V
DD
= 1.5V, V
PGND
= V
SGND
= 0V, V
SHDN
= 1.5V, V
SS
= V
PVSS
, C1 = C2 = 1µF, C
IN
= 1µF, R
L
= 32Ω, R
F
= 60kΩ, R
IN
= 10kΩ, T
A
=
T
MIN
to T
MAX,
unless otherwise noted. Typical values are at T
A
= +25°C.) (See the
Functional Diagrams.
) (Note 1)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
R
L
= 32Ω 10 24
V
DD
= 1.5V
R
L
= 16Ω 25
V
DD
= 1.0V, R
L
= 32Ω 7
Output Power (Note 3) P
OUT
V
DD
= 0.9V, R
L
= 32Ω 6
mW
R
L
= 32Ω, P
OUT
= 12mW, f = 1kHz 0.006
Total Harmonic Distortion Plus
Noise (Note 5)
THD+N
R
L
= 16Ω, P
OUT
= 15mW, f = 1kHz 0.015
%
BW = 22Hz to 22kHz 89
Signal-to-Noise Ratio SNR R
L
= 32Ω, P
OUT
= 12mW
A-weighted filter 92
dB
Slew Rate SR 0.3 V/µs
Maximum Capacitive Load C
L
No sustained oscillations 150 pF
Crosstalk XTALK f
IN
= 1.0kHz, R
L
= 32Ω, P
OUT
= 5mW 100 dB
Into shutdown 72.8
Click-and-Pop Level K
CP
R
L
= 32Ω, peak voltage,
A-weighted, 32 samples per
second (Note 4)
Out of shutdown 72.8
dBV
ESD Protection V
ESD
Human Body Model (OUTR, OUTL) ±8 kV
R
L
= 32Ω -120
Attenuation in Shutdown A
TT
SD
V
SHDN
= 0V
R
L
= 10kΩ -75
dB
