Datasheet

MAX9744
20W Stereo Class D Speaker Amplifier
with Volume Control
_______________________________________________________________________________________ 9
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.)
OUTPUT POWER vs. SUPPLY VOLTAGE
MAX9744 toc25
SUPPLY VOLTAGE (V)
OUTPUT POWER (W)
141068
4
8
12
16
0
412
R
L
= 8Ω
f
IN
= 1kHz
PWM MODE
THD+N = 10%
THD+N = 1%
OUTPUT POWER vs. LOAD RESISTANCE
MAX9744 toc26
LOAD RESISTANCE (
Ω
)
OUTPUT POWER (W)
3015510
4
8
12
20
16
0
02520
PVDD = 12V
f = 1kHz
FILTERLESS MODULATION
THD+N = 10%
THD+N = 1%
OUTPUT POWER vs. LOAD RESISTANCE
MAX9744 toc27
LOAD RESISTANCE (
Ω
)
OUTPUT POWER (W)
3015510
1
2
4
3
0
02520
PVDD = 5V
f = 1kHz
PWM MODE
THD+N = 10%
THD+N = 1%
CASE TEMPERATURE
vs. OUTPUT POWER
MAX9744 toc28
OUTPUT POWER (W)
CASE TEMPERATURE (°C)
18936
25
50
125
100
75
0
01512
f
IN
= 1kHz
R
L
= 4Ω
PVDD = 14V
PWM MODE
PVDD = 12V
PWM MODE
PVDD = 14V
FILTERLESS MODULATION
PVDD = 12V
FILTERLESS MODULATION
CASE TEMPERATURE
vs. OUTPUT POWER
MAX9744 toc29
OUTPUT POWER (W)
CASE TEMPERATURE (°C)
12624
25
75
50
0
0108
f
IN
= 1kHz
R
L
= 8Ω
PVDD = 12V
PWM MODE
PVDD = 14V
PWM MODE
PVDD = 14V
FILTERLESS MODULATION
PVDD = 12V
FILTERLESS MODULATION
POWER-SUPPLY REJECTION RATIO (PVDD)
vs. FREQUENCY
MAX9744 toc30
FREQUENCY (Hz)
PSRR (dB)
10k1k100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
-100
10 100k
PWM MODE
FILTERLESS MODULATION
PVDD = 12V
V
RIPPLE
= 200mV
P-P
EMI WITH FERRITE BEAD FILTERS
(V
DD
= 12V, 1m CABLE, 8Ω LOAD)
MAX9744 toc32
OUTPUT MAGNITUDE (dBV)
5
10
15
20
25
30
35
40
FREQUENCY (MHz)
220
200
60
80
100
140
160
120
180
30
240
260
280
300
EN5022 B LIMIT
POWER-SUPPLY REJECTION RATIO (V
DD
)
vs. FREQUENCY
MAX9744 toc31
FREQUENCY (Hz)
PSRR (dB)
10k1k100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
-100
10 100k
PWM MODE
FILTERLESS MODULATION
V
DD
= 3.3V
V
RIPPLE
= 100mV
P-P