Rainbow Electronics MAX9770 User Manual
General Description
The MAX9770 combines a mono, filterless, Class D
speaker amplifier and stereo DirectDrive headphone
amplifiers in a single device. The MAX9770 operates
from a single 2.5V to 5.5V supply and includes features
that reduce external component count, system cost,
board space, and offer improved audio reproduction.
The speaker amplifier makes use of Maxim’s patented
Class D architecture, providing Class AB performance
with Class D efficiency, conserving board space, and
extending battery life. The speaker amplifier delivers
1.2W into an 8Ω load while offering efficiencies above
85%. A spread-spectrum scheme reduces radiated
emissions caused by the modulation frequency.
Furthermore, the MAX9770 oscillator can be synchronized to an external clock through the SYNC input,
avoiding possible problem frequencies inside a system.
The speaker amplifier features a low 0.025% THD+N,
high 70dB PSRR, and SNR in excess of 90dB.
The headphone amplifiers feature Maxim’s patented
DirectDrive architecture that produces a ground-referenced output from a single supply, eliminating the need
for large DC-blocking capacitors. The headphone amplifiers deliver up to 80mW into a 16Ω load, feature low
0.015% THD+N, high 80dB PSRR, and ±8kV ESD-protected outputs. A headphone sense input detects the
presence of a headphone, and automatically configures
the amplifiers for either speaker or headphone mode.
The MAX9770 includes internally set, logic-selectable
gain, and a comprehensive input multiplexer/mixer, allowing multiple audio sources to be selected and for true
mono reproduction of a stereo source in speaker mode.
Industry-leading click-and-pop suppression eliminates
audible transients during power and shutdown cycles. A
low-power shutdown mode decreases supply current
consumption to 0.1µA, further extending battery life.
The MAX9770 is offered in space-saving, thermally efficient 28-pin TQFN (5mm x 5mm x 0.8mm) and 28-pin
TSSOP packages. The MAX9770 features thermal-overload and output short-circuit protection, and is specified
over the extended -40°C to +85°C temperature range.
Applications
Cellular Phones
PDAs
Compact Notebooks
Features
♦ 1.2W Filterless Class D Amplifier Passes FCC
Class B Radiated Emissions Standards with
100mm of Cable
♦ Unique Spread-Spectrum Mode Offers 5dB
Emissions Improvement Over Conventional
Methods
♦ 80mW DirectDrive Headphone Amplifier
Eliminates Bulky DC-Blocking Capacitors
♦ High 80dB PSRR at 217Hz
♦ 85% Efficiency
♦ Low 0.015% THD+N
♦ Industry-Leading Click-and-Pop Suppression
♦ Integrated 3-Way Input Mixer/Multiplexer
♦ Logic-Selectable Gain
♦ Short-Circuit and Thermal Protection
♦ ±8kV ESD-Protected Headphone Outputs
♦ Low-Power Shutdown Mode
♦ Available in Space-Saving, Thermally Efficient
Packages
28-Pin TQFN (5mm x 5mm x 0.8mm)
28-Pin TSSOP
MAX9770
1.2W Low-EMI, Filterless, Mono Class D Amplifier
with Stereo Dir ectDrive Headphone Amplifiers
________________________________________________________________ Maxim Integrated Products 1
SPKR
(MONO)
MAX9770
CLASS
D
V
DD
DirectDrive
STEREO
HEADPHONE
L1IN
L2IN
R1IN
R2IN
MONO
GAIN SEL
INPUT SEL
MUTE
SHDN
HPS
Ordering Information
Simplified Block Diagram
19-3134; Rev 0; 5/04
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
Pin Configuration appears at end of data sheet.
†
Lead-free package.
*EP = Exposed paddle.
PART TEMP RANGE PIN-PACKAGE
MAX9770ETI
MAX9770EUI -40oC to +85oC 28 TSSOP
†
-40oC to +85oC 28 TQFN-EP*
MAX9770
1.2W Low-EMI, Filterless, Mono Class D Amplifier
with Stereo Dir ectDrive Headphone Amplifiers
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VDD= PVDD= CPVDD= 3.3V, GND = PGND = CPGND = 0V, SHDN = 3.3V, C1 = C2 = 1µF, C
BIAS
= 0.047µF, SYNC = GND, RL= ∞,
speaker load connected between OUT+ and OUT-, headphone load connected between HPOUT_ and GND, T
A
= T
MIN
to T
MAX
,
unless otherwise noted. Typical values are at T
A
= +25°C.) (Notes 1, 2)
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
GND to PGND to CPGND......................................-0.3V to +0.3V
V
DD
to PVDDto CPVDD..........................................-0.3V to +0.3V
V
DD
to GND..............................................................................6V
PV
DD
to PGND .........................................................................6V
CPV
DD
to CPGND....................................................................6V
CPV
SS
to CPGND....................................................................-6V
SV
SS
to GND...........................................................................-6V
C1N..........................................(PV
SS
- 0.3V) to (CPGND + 0.3V)
HPOUT_ to GND ....................................................................±3V
All other pins to GND..................................-0.3V to (V
DD
+ 0.3V)
Continuous Current Into/Out of:
PV
DD
, PGND, OUT_......................................................600mA
PV
SS
..............................................................................260mA
Duration of HPOUT_ Short Circuit to V
DD
, PVDD,
GND, PGND...........................................................Continuous
Duration of Short Circuit between
HPOUTL and HPOUTR ..........................................Continuous
Duration of OUT_ Short Circuit to V
DD
, PVDD, GND, PGND ..10s
Duration of Short Circuit Between OUT+ and OUT-...............10s
Continuous Power Dissipation (T
A
= +70°C)
28-Pin TQFN (derate 20.8mW/°C above +70°C) .......1667mW
28-Pin TSSOP (derate 12.8mW°C above +70°C) ......1026mW
Junction Temperature......................................................+150°C
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10s).................................+300°C
PARAMETER
CONDITIONS MIN TYP
UNITS
GENERAL
Supply Voltage Range V
DD
Inferred from PSRR test 2.5 5.5 V
Headphone mode 5.5 10
Quiescent Supply Current I
DD
No load
Speaker mode 5.2 7.5
mA
Shutdown Supply Current I
SHDN
SHDN = HPS = GND 0.1 10 µA
Shutdown to Full Operation t
ON
50 ms
MONO 7 10
Input Impedance R
IN
(Note 3)
INL_, INR_ 14 20
kΩ
Bias Voltage V
BIAS
1.1 1.25 1.4 V
Feedthrough
From any unselected input to any output,
f = 10kHz
70 dB
SPEAKER AMPLIFIER (GAIN1 = GAIN2 = VDD, HPS = GND)
Output Offset Voltage V
OS
±15 ±70 mV
VDD = 2.5V to 5.5V 50 70
70
68
Power-Supply Rejection Ratio PSRR
50
dB
RL = 8Ω 550
RL = 4Ω 900
Output Power P
OUT
f = 1kHz,
THD+N = 1%,
GAIN1 = 1,
GAIN2 = 0
V
DD
= 5V RL = 8Ω 1200
mW
RL = 8Ω, P
OUT
= 300mW, f = 1kHz
Total Harmonic Distortion Plus
Noise
RL = 4Ω, P
OUT
= 300mW, f = 1kHz 0.03
%
SYMBOL
MAX
THD+N
V
= 200mV
(Note 4)
RIPPLE
V
= 200mV
RIPPLE
V
= 200mV
RIPPLE
VDD = 3.3V
, f = 217Hz
P-P
, f = 1kHz
P-P
, f = 20kHz
P-P
0.025
MAX9770
1.2W Low-EMI, Filterless, Mono Class D Amplifier
with Stereo Dir ectDrive Headphone Amplifiers
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(VDD= PVDD= CPVDD= 3.3V, GND = PGND = CPGND = 0V, SHDN = 3.3V, C1 = C2 = 1µF, C
BIAS
= 0.047µF, SYNC = GND, RL= ∞,
speaker load connected between OUT+ and OUT-, headphone load connected between HPOUT_ and GND, T
A
= T
MIN
to T
MAX
,
unless otherwise noted. Typical values are at T
A
= +25°C.) (Notes 1, 2)
PARAMETER
CONDITIONS MIN TYP
UNITS
Signal-to-Noise Ratio SNR RL = 8Ω, V
OUT
= 2V
RMS
, A-weighted 85.9 dB
SYNC = GND 980 1100
SYNC = FLOAT
1450
Output Switching Frequency F
S
SYNC = V
DD
1220
kHz
SYNC Frequency Lock Range 800
kHz
Efficiency η PO = 1000mW, f = 1kHz 85 %
GAIN1 = 0, GAIN2 = 0 6
GAIN1 = 0, GAIN2 = 1 3
GAIN1 = 1, GAIN2 = 0 9
Gain A
V
GAIN1 = 1, GAIN2 = 1 0
dB
Gain Accuracy ±5%
Speaker Path Off-Isolation
HPS = V
DD
, headphone amplifier active,
f = 1kHz
102 dB
HEADPHONE AMPLIFIER (GAIN1 = 1, GAIN2 = 0, HPS = V
DD
)
Output Offset Voltage V
OS
±5 ±10 mV
VDD = 2.5V to 5.5V 65 76
85
V
RIPPLE
= 200mV
P-P
, f = 1kHz 82
Power-Supply Rejection Ratio PSRR
56
dB
RL = 32Ω 40 55
RL = 16Ω 40
RL = 32Ω 60
Output Power P
OUT
f = 1kHz,
THD+N = 1%
V
DD
= 5V
R
L
= 16Ω 80
mW
RL = 32Ω, P
OUT
= 50mW, f = 1kHz
Total Harmonic Distortion Plus
Noise
RL = 16Ω, P
OUT
= 35mW, f = 1kHz 0.03
%
Signal-to-Noise Ratio SNR
R
L
= 32Ω, V
OUT
= 300mV
RMS
,
BW = 22Hz to 22kHz
101 dB
Crosstalk
Between channels, f = 1kHz,
V
IN
= 200mV
P-P
80 dB
Headphone Off-Isolation
HPS = GND, speaker amplifier active,
f = 1kHz
96 dB
SYMBOL
(Note 3)
THD+N
V
= 200mV
V
RIPPLE
= 200mV
RIPPLE
VDD = 3.3V
P-P
P-P
, f = 217kHz
, f = 20kHz
1280
±120kHz
0.015
MAX
1220
1620
2000
10
0.001
10 100 10k 100k
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY (SPEAKER MODE)
0.01
0.1
1
MAX9770 toc01
FREQUENCY (Hz)
THD+N (%)
1k
VDD = +5V
R
L
= 4
Ω
P
OUT
= 25mW
P
OUT
= 1000mW
10
0.001
10 100 10k 100k
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY (SPEAKER MODE)
0.01
0.1
1
MAX9770 toc02
FREQUENCY (Hz)
THD+N (%)
1k
RL = 4
Ω
P
OUT
= 100mW
P
OUT
= 500mW
10
0.001
10 100 10k 100k
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY (SPEAKER MODE)
0.01
0.1
1
MAX9770 toc03
FREQUENCY (Hz)
THD+N (%)
1k
RL = 8
Ω
P
OUT
= 40mW
P
OUT
= 400mW
Typical Operating Characteristics
(VDD= 3.3V, BW = 22Hz to 22kHz, GAIN1 = 1, GAIN2 = 0, spread-spectrum mode, headphone outputs in phase.)
MAX9770
1.2W Low-EMI, Filterless, Mono Class D Amplifier
with Stereo Dir ectDrive Headphone Amplifiers
4 _______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS (continued)
(VDD= PVDD= CPVDD= 3.3V, GND = PGND = CPGND = 0V, SHDN = 3.3V, C1 = C2 = 1µF, C
BIAS
= 0.047µF, SYNC = GND, RL= ∞,
speaker load connected between OUT+ and OUT-, headphone load connected between HPOUT_ and GND, T
A
= T
MIN
to T
MAX
,
unless otherwise noted. Typical values are at T
A
= +25°C.) (Notes 1, 2)
PARAMETER
CONDITIONS MIN TYP
UNITS
Capacitive-Load Drive C
L
1000 pF
GAIN1 = 0, GAIN2 = 0 7
GAIN1 = 0, GAIN2 = 1 4
GAIN1 = 1, GAIN2 = 0 -2
Gain A
V
GAIN1 = 1, GAIN2 = 1 1
dB
Gain Accuracy
%
ESD Protection HPOUTR, HPOUTL, IEC Air Discharge ±8kV
DIGITAL INPUTS (SHDN, SYNC, HPS, GAIN_, SEL_)
Input Voltage High V
IH
2V
Input Voltage Low V
IL
0.8 V
SYNC input ±25
Input Leakage Current
All other logic inputs ±1
µA
HPS Input Current HPS = GND -10 µA
Note 1: All devices are 100% production tested at +25°C. All temperature limits are guaranteed by design.
Note 2: Speaker amplifier testing performed with a resistive load in series with an inductor to simulate an actual speaker load. For
R
L
= 4Ω, L = 47µH. For RL= 8Ω, L = 68µH.
Note 3: Guaranteed by design, not production tested.
Note 4: PSRR is specified with the amplifier inputs connected to GND through C
IN
.
SYMBOL
MAX
±2.5
MAX9770
1.2W Low-EMI, Filterless, Mono Class D Amplifier
with Stereo Dir ectDrive Headphone Amplifiers
_______________________________________________________________________________________ 5
10
0.001
10 100 10k 100k
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY (SPEAKER MODE)
0.01
0.1
1
MAX9770 toc04
FREQUENCY (Hz)
THD+N (%)
1k
VDD = 5V
P
OUT
= 1W
R
L
= 8
Ω
SSM MODE
FFM MODE
100
0
400 800 1200
1600
10
1
0.1
0.01
0.001
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (SPEAKER MODE)
MAX9770 toc05
OUTPUT POWER (mW)
THD+N (%)
VDD = 5V
R
L
= 8
Ω
f = 20Hz
f = 1kHz
f = 10kHz
100
0
200 600
400
800
1000
10
1
0.1
0.01
0.001
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (SPEAKER MODE)
MAX9770 toc06
OUTPUT POWER (mW)
THD+N (%)
f = 20Hz
f = 1kHz
f = 10kHz
RL = 4
Ω
100
0
200 400 600
800
10
1
0.1
0.01
0.001
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (SPEAKER MODE)
MAX9770 toc07
OUTPUT POWER (mW)
THD+N (%)
RL = 8
Ω
f = 20Hz
f = 1kHz
f = 10kHz
100
0
400 800 1200
1600
10
1
0.1
0.01
0.001
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (SPEAKER MODE)
MAX9770 toc08
OUTPUT POWER (mW)
THD+N (%)
VDD = 5V
f = 1kHz
R
L
= 8
Ω
SSM MODE
FFM MODE
1.75
0
110100
OUTPUT POWER
vs. LOAD RESISTANCE (SPEAKER MODE)
0.50
0.25
MAX9770 toc09
LOAD RESISTANCE (Ω)
OUTPUT POWER (W)
0.75
1.00
1.25
1.50
VDD = 5V
f = 1kHz
THD+N = 10%
THD+N = 1%
1.0
0
110100
OUTPUT POWER
vs. LOAD RESISTANCE (SPEAKER MODE)
0.2
MAX9770 toc10
LOAD RESISTANCE (Ω)
OUTPUT POWER (W)
0.4
0.6
0.8
f = 1kHz
THD+N = 10%
THD+N = 1%
2.0
1.5
1.0
0.5
0
2.5 4.03.0 3.5 4.5 5.0 5.5
OUTPUT POWER
vs. SUPPLY VOLTAGE (SPEAKER MODE)
MAX9770 toc11
SUPPLY VOLTAGE (V)
OUTPUT POWER (W)
f = 1kHz
R
L
= 8
Ω
THD+N = 10%
THD+N = 1%
0
30
20
10
50
40
90
80
70
60
100
0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
EFFICIENCY vs. OUTPUT POWER
MAX9770 toc12
OUTPUT POWER (W)
EFFICIENCY (%)
VDD = 5V
f = 1kHz
R
L
= 8Ω
Typical Operating Characteristics (continued)
(VDD= 3.3V, BW = 22Hz to 22kHz, GAIN1 = 1, GAIN2 = 0, spread-spectrum mode, headphone outputs in phase.)
MAX9770
1.2W Low-EMI, Filterless, Mono Class D Amplifier
with Stereo Dir ectDrive Headphone Amplifiers
6 _______________________________________________________________________________________
Typical Operating Characteristics (continued)
(VDD= 3.3V, BW = 22Hz to 22kHz, GAIN1 = 1, GAIN2 = 0, spread-spectrum mode, headphone outputs in phase.)
0
30
20
10
40
50
60
70
80
90
100
00.40.2 0.6 0.8 1.0
EFFICIENCY vs. OUTPUT POWER
MAX9770 toc13
OUTPUT POWER (W)
EFFICIENCY (%)
RL = 8Ω
RL = 4Ω
f = 1kHz
0
-10
-20
-30
-40
-50
-60
-70
-80
10 1k 10k100 100k
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY (SPEAKER MODE)
MAX9770 toc14
FREQUENCY (Hz)
PSRR (dB)
V
RIPPLE
= 200mV
P-P
RL = 8Ω
-140
-100
-120
-60
-80
-20
-40
0
OUTPUT SPECTRUM
(SPEAKER MODE)
MAX9770 toc15
FREQUENCY (kHz)
MAGNITUDE (dB)
0510
15
20
RL = 8Ω
f = 1kHz
FFM MODE
V
IN
= -60dBV
-140
-100
-120
-60
-80
-20
-40
0
OUTPUT SPECTRUM
(SPEAKER MODE)
MAX9770 toc16
FREQUENCY (kHz)
MAGNITUDE (dB)
0510
15
20
RL = 8Ω
f = 1kHz
SSM MODE
V
IN
= -60dBV
-160
-100
-120
-140
-60
-80
-20
-40
0
OUTPUT SPECTRUM
(SPEAKER MODE)
MAX9770 toc17
FREQUENCY (kHz)
MAGNITUDE (dB)
0510
15
20
RL = 8Ω
f = 1kHz
SSM MODE
A-WEIGHTED
V
IN
= -60dBV
0
-100
1M 10M 100M
WIDEBAND OUTPUT SPECTRUM
(SPEAKER MODE)
-80
MAX9770 toc18
FREQUENCY (Hz)
MAGNITUDE (dB)
-60
-40
-20
-30
-50
-70
-90
-10
FFM MODE
RBW = 10kHz
0
-100
1M 10M 100M
WIDEBAND OUTPUT SPECTRUM
(SPEAKER MODE)
-80
MAX9770 toc19
FREQUENCY (Hz)
MAGNITUDE (dB)
-60
-40
-20
-30
-50
-70
-90
-10
SSM MODE
RBW = 10kHz
STARTUP WAVEFORM
(SPEAKER MODE)
MAX9770 toc20
4ms/div
2V/divSHDN
OUT+ - OUT-
500mV/div
RL = 8Ω
f = 1kHz
MIXER OUTPUT
MAX9770 toc21
400µs/div
10kHz
1V/div
4kHz
1V/div
1kHz
2V/div
IN_1
IN_2
MONO
OUT
1V/div
MAX9770
1.2W Low-EMI, Filterless, Mono Class D Amplifier
with Stereo Dir ectDrive Headphone Amplifiers
_______________________________________________________________________________________ 7
10
0.001
10 100 10k 100k
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY (HEADPHONE MODE)
0.01
0.1
1
MAX9770 toc22
FREQUENCY (Hz)
THD+N (%)
1k
P
OUT
= 10mW
P
OUT
= 50mW
VDD = 5V
R
L
= 16Ω
10
0.001
10 100 10k 100k
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY (HEADPHONE MODE)
0.01
0.1
1
MAX9770 toc23
FREQUENCY (Hz)
THD+N (%)
1k
P
OUT
= 10mW
P
OUT
= 50mW
VDD = 5V
R
L
= 32Ω
10
0.001
10 100 10k 100k
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY (HEADPHONE MODE)
0.01
0.1
1
MAX9770 toc24
FREQUENCY (Hz)
THD+N (%)
1k
P
OUT
= 10mW
P
OUT
= 35mW
RL = 16Ω
10
0.001
10 100 10k 100k
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY (HEADPHONE MODE)
0.01
0.1
1
MAX9770 toc25
FREQUENCY (Hz)
THD+N (%)
1k
P
OUT
= 10mW
P
OUT
= 50mW
RL = 32Ω
100
10
1
0.1
0.01
0.001
0408020 60 100
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (HEADPHONE MODE)
MAX9770 toc26
OUTPUT POWER (mW)
THD+N (%)
VDD = 5V
R
L
= 16Ω
f = 1kHz
f = 20Hz
f = 10kHz
100
10
1
0.1
0.01
0.001
0
60
20 40 80
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (HEADPHONE MODE)
MAX9770 toc27
OUTPUT POWER (mW)
THD+N (%)
f = 20Hz
VDD = 5V
R
L
= 32Ω
f = 1kHz
f = 10kHz
100
10
1
0.1
0.01
0.001
0
50
40
2010
30 60
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (HEADPHONE MODE)
MAX9770 toc28
OUTPUT POWER (mW)
THD+N (%)
RL = 16Ω
f = 1kHz
f = 10kHz
f = 20Hz
100
10
1
0.1
0.01
0.001
0
60
20 40 80
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (HEADPHONE MODE)
MAX9770 toc29
OUTPUT POWER (mW)
THD+N (%)
f = 20Hz
RL = 32Ω
f = 1kHz
f = 10kHz
100
90
80
70
60
50
40
30
20
10
0
10 100 1000
OUTPUT POWER
vs. LOAD RESISTANCE (HEADPHONE MODE)
MAX9770 toc30
LOAD RESISTANCE (Ω)
OUTPUT POWER (mW)
VDD = 5V
f = 1kHz
THD+N = 10%
THD+N = 1%
Typical Operating Characteristics (continued)
(VDD= 3.3V, BW = 22Hz to 22kHz, GAIN1 = 1, GAIN2 = 0, spread-spectrum mode, headphone outputs in phase.)
MAX9770
1.2W Low-EMI, Filterless, Mono Class D Amplifier
with Stereo Dir ectDrive Headphone Amplifiers
8 _______________________________________________________________________________________
Typical Operating Characteristics (continued)
(VDD= 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)
RL = 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)
RL = 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
RL = 16Ω
RL = 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
VDD = 5V
V
RIPPLE
= 200mV
P-P
RL = 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
RL = 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
RL = 32Ω
f = 1kHz
V
IN
= -60dBV
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