Datasheet

MAX9744
20W Stereo Class D Speaker Amplifier
with Volume Control
______________________________________________________________________________________ 11
CROSSTALK vs. FREQUENCY
MAX9744 toc41
FREQUENCY (Hz)
CROSSTALK (dB)
10k1k100
-100
-80
-60
-40
-20
0
-120
10 100k
LEFT TO RIGHT
RIGHT TO LEFT
V
IN
= 200mV
RMS
CROSSTALK vs. AMPLITUDE
MAX9744 toc42
AMPLITUDE (dBV)
CROSSTALK (dB)
100-20 -10-40 -30-50
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
-100
-60 20
RIGHT TO LEFT
LEFT TO RIGHT
R
L
= 8Ω
f = 1kHz
TURN-ON/OFF RESPONSE
MAX9744 toc43
100ms/div
OUTPUT
SHDN
2V/div
SUPPLY CURRENT (PVDD)
vs. SUPPLY VOLTAGE
MAX9744 toc45
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
12106 8
2
4
6
8
12
10
14
16
0
414
PWM MODE
FILTERLESS MODULATION
VOLUME CONTROL LEVEL
vs. VOLUME CONTROL VOLTAGE
MAX9744 toc44
V
VOL
(V)
VOLUME LEVEL (dB)
3.02.52.01.51.00.5
-100
-80
-60
-40
-20
0
20
-120
0 3.5
VOLUME CONTROL LEVEL
SHUTDOWN CURRENT
vs. SUPPLY VOLTAGE
MAX9744 toc47
SUPPLY VOLTAGE (V)
SHUTDOWN CURRENT (μA)
148106
0.5
0.6
0.7
0.8
0.4
412
SHUTDOWN CURRENT = I
PVDD
+ I
DD
V
DD
= 3.3V
SUPPLY CURRENT (V
DD
)
vs. SUPPLY VOLTAGE
MAX9744 toc46
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
3.83.63.43.2
10
15
20
25
30
5
3.0 4.0
PWM MODE
FILTERLESS MODULATION
Typical Operating Characteristics (continued)
(V
PVDD
= 12V, V
DD
= 3.3V, V
GND
= V
PGND
= 0V, V
MUTE
= 0V; max volume setting; all speaker load resistors connected between
OUT_+ and OUT_- with an inductor in series, 8Ω load, L = 68µH, 4Ω load, L= 33µH. R
L
= ∞, unless otherwise stated, C
BIAS
= 2.2µF,
C
IN
= 0.47µF, R
IN
= 20kΩ, R
F_
= 20kΩ, spread-spectrum mode, T
A
= +25°C, unless otherwise noted.)