Datasheet
MAX9791/MAX9792
Windows Vista-Compliant Class D Speaker
Amplifiers with DirectDrive Headphone Amplifiers
4 _______________________________________________________________________________________
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Class D Switching Frequency f
SPK
948 1158 kHz
Spread-Spectrum Bandwidth ±15 kHz
Efficiency P
OUT
= 1.5W, f
IN
= 1kHz, R
L
= 8 (Note 5) 83 %
HEADPHONE AMPLIFIER
R
L
= 16 100
Output Power P
OUT
THD+N = 1%,
f = 1kHz,
T
A
= +25°C
R
L
= 32 180
mW
R
L
= 32, f
IN
= 6kHz, 20kHz AES17,
V
IN
= -3dBFS = 212mV
RMS
-78
R
L
= 10k, f
IN
= 6kHz, 20kHz AES17,
V
IN
= -3dBFS = 500mV
RMS
-87
dBFS
R
L
= 32, P
OUT
= 100mW, f = 1kHz 0.006
Total Harmonic Distortion Plus
Noise
THD+N
R
L
= 16, P
OUT
= 75mW, f = 1kHz 0.014
%
V
HPVDD
= 2.7V to 5.5V, T
A
= +25°C 70 107
f = 1kHz, V
RIPPLE
= 200mV
P-P
91
Power-Supply Rejection Ratio PSRR
f = 10kHz, V
RIPPLE
= 200mV
P-P
80
dB
Feedback Impedance R
FHP
38.2 40.2 42.2 k
Gain A
V
R
IN2
= 40.2k 0 dB
Output Offset Voltage V
OS
T
A
= +25°C ±0.3 ±3 mV
Into shutdown -81
Click-and-Pop Level K
CP
R
L
= 32,
peak voltage,
A-weighted, 32 samples
per second (Notes 6, 7)
Out of
shutdown
-72.5
dBV
A-weighted 102
Signal-to-Noise Ratio SNR
R
L
= 32, P
OUT
= 40mW,
f
IN
= 1kHz
20Hz to 20kHz 94
dB
Noise V
N
A-weighted 8 µV
RMS
Maximum Capacitive Load
C
L
No sustained oscillations 100 pF
R
L
= 32, V
IN
=
-20dBFS = 30mV
RMS
82
L to R, R to L, f
IN
= 1kHz, COM
and SENSE
connected
R
L
= 10k, V
IN
=
-20dBFS = 0.7mV
RMS
89
R
L
= 32, V
IN
=
-20dBFS = 30mV
RMS
64
L to R, R to L, f
IN
= 15kHz, COM
and SENSE
connected
R
L
= 10k, V
IN
=
-20dBFS = 70.7mV
RMS
70
Crosstalk
SPKR to HP, R
LSPKR
= 8, P
SPKR
= 1W,
R
LHP
= 32, f
IN
= 1Hz
80
dB
ELECTRICAL CHARACTERISTICS (continued)
(V
AVDD
= V
PVDD
= V
HPVDD
= 5V, V
GND
= V
PGND
= V
CPGND
= 0, I
LDO_OUT
= 0, C
LDO
= 2µF (C
LDO
= 4µF for 1.8V LDO option),
C1 = C2 = 1µF. R
L
= ∞, unless otherwise specified. R
IN1
= 20kΩ (A
VSPKR
= 12dB), R
IN2
= 40.2kΩ (A
VHP
= 0dB), C
IN1
= 470nF,
C
IN2
=C
COM
= 1µF, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 3)