Owner's manual

MAX9770
1.2W Low-EMI, Filterless, Mono Class D Amplifier
with Stereo DirectDrive Headphone Amplifiers
8 _______________________________________________________________________________________
Typical Operating Characteristics (continued)
(V
DD
= 3.3V, BW = 22Hz to 22kHz, GAIN1 = 1, GAIN2 = 0, spread-spectrum mode, headphone outputs in phase.)
80
70
60
50
40
30
20
10
0
10 100 1000
OUTPUT POWER
vs. LOAD RESISTANCE (HEADPHONE MODE)
MAX9770 toc31
LOAD RESISTANCE (Ω)
OUTPUT POWER (mW)
f = 1kHz
THD+N = 10%
THD+N = 1%
0
30
20
10
40
50
60
70
80
90
100
2.5 3.53.0 4.0 4.5 5.0 5.5
OUTPUT POWER
vs. SUPPLY VOLTAGE (HEADPHONE MODE)
MAX9770 toc32
SUPPLY VOLTAGE (V)
OUTPUT POWER (mW)
R
L
= 16Ω
f = 1kHz
THD+N = 10%
THD+N = 1%
0
10
20
30
40
50
60
70
80
2.5 3.53.0 4.0 4.5 5.0 5.5
OUTPUT POWER
vs. SUPPLY VOLTAGE (HEADPHONE MODE)
MAX9770 toc33
SUPPLY VOLTAGE (V)
OUTPUT POWER (mW)
R
L
= 32Ω
f = 1kHz
THD+N = 10%
THD+N = 1%
0
50
100
150
200
250
300
06030 90 120 150
POWER DISSIPATION
vs. OUTPUT POWER (HEADPHONE MODE)
MAX9770 toc34
OUTPUT POWER (mW)
POWER DISSIPATION (mW)
f = 1kHz
P
OUT
= P
OUTL
+ P
OUTR
R
L
= 16Ω
R
L
= 32Ω
0
-100
10 100 1k 10k 100k
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY (HEADPHONE MODE)
-80
MAX9770 toc35
FREQUENCY (Hz)
PSRR (dB)
-60
-40
-20
-30
-50
-70
-90
-10
V
DD
= 5V
V
RIPPLE
= 200mV
P-P
R
L
= 32Ω
0
-100
10 100 1k 10k 100k
CROSSTALK vs. FREQUENCY
(HEADPHONE MODE)
-80
MAX9770 toc36
FREQUENCY (Hz)
CROSSTALK (dB)
-60
-40
-20
-30
-50
-70
-90
-10
R
L
= 32Ω
f = 1kHz
V
IN
= 200mV
P-P
LEFT TO RIGHT
RIGHT TO LEFT
0
-100
10 100 1k 10k 100k
FEEDTHROUGH vs. FREQUENCY
-80
MAX9770 toc37
FREQUENCY (Hz)
FEEDTHROUGH (dB)
-60
-40
-20
-30
-50
-70
-90
-10
SEL1 = 0
SEL2 = 1
IN1_ = GND
IN2_ = DRIVEN
V
IN
= 2V
P-P
HEADPHONE MODE
SPEAKER MODE
0
10
30
20
50
40
60
20 30 40 50
OUTPUT POWER
vs. CHARGE-PUMP CAPACITANCE
MAX9770 toc38
LOAD (Ω)
OUTPUT POWER (mW)
C1 = C2 = 1µF
C1 = C2 = 0.47µF
f = 1kHz
THD+N = 1%
-140
-100
-120
-60
-80
-20
-40
0
OUTPUT SPECTRUM
(HEADPHONE MODE)
MAX9770 toc39
FREQUENCY (kHz)
MAGNITUDE (dB)
0 5 10 15 20
R
L
= 32Ω
f = 1kHz
V
IN
= -60dBV