Datasheet

MAX9791/MAX9792
Windows Vista-Compliant Class D Speaker
Amplifiers with DirectDrive Headphone Amplifiers
12 ______________________________________________________________________________________
OUTPUT FREQUENCY SPECTRUM
(HEADPHONE MODE)
MAX9791 toc32
FREQUENCY (kHz)
OUTPUT FREQUENCY SPECTRUM (dB)
51015
-120
-100
-40
-20
0
-80
-60
-140
020
RIGHT AND LEFT
FS = 707mV
RMS
V
IN
= -60dBFS
R
L
= 32
Ω
MAX9791 toc33
HP_EN
2V/div
HP_
500mV/div
200µs/div
STARTUP WAVEFORM
MAX9791 toc34
HP_EN
2V/div
HP_
500mV/div
200µs/div
SHUTDOWN WAVEFORM
-130
-90
-110
-50
-70
-30
-10
500 15001000 2000 2500 3000
HEADPHONE RF IMMUNITY
vs. FREQUENCY
MAX9791 toc35
FREQUENCY (MHz)
AMPLITUDE (dBV)
LEFT
RIGHT
R
L
= 32Ω
HEADPHONE
Typical Operating Characteristics (continued)
(V
AVDD
= V
PVDD
= V
HPVDD
= 5V, V
GND
= V
PGND
= V
CPGND
= 0, I
LDO_OUT
= 0, C
LDO
= 2 x 1µF, C1 = C2 = 1µF. R
L
= ∞, unless oth-
erwise specified. R
IN1
= 20kΩ (A
VSPKR
= 12dB), R
IN2
= 40.2kΩ (A
VHP
= 0dB), C
IN1
= 470nF, C
IN2
= C
COM
= 1µF, measurement BW
= 20kHz AES17, T
A
= +25°C, unless otherwise noted. Speaker mode: SPKR_EN = 0, HP_EN = 0. Headphone mode: SPKR_EN = 1,
HP_EN = 1.)