General Description
The MAX9703/MAX9704 mono/stereo Class D audio
power amplifiers provide Class AB amplifier performance
with Class D efficiency, conserving board space and
eliminating the need for a bulky heatsink. Using a Class
D architecture, these devices deliver up to 15W while
offering up to 78% efficiency. Proprietary and patent-pro-
tected modulation and switching schemes render the tra-
ditional Class D output filter unnecessary.
The MAX9703/MAX9704 offer two modulation schemes:
a fixed-frequency mode (FFM), and a spread-spectrum
mode (SSM) that reduces EMI-radiated emissions due
to the modulation frequency. The device utilizes a fully
differential architecture, a full bridged output, and com-
prehensive click-and-pop suppression.
The MAX9703/MAX9704 feature high 80dB PSRR, low
0.07% THD+N, and SNR in excess of 95dB. Short-cir-
cuit and thermal-overload protection prevent the
devices from being damaged during a fault condition.
The MAX9703 is available in a 32-pin TQFN (5mm x
5mm x 0.8mm) package. The MAX9704 is available in a
32-pin TQFN (7mm x 7mm x 0.8mm) package. Both
devices are specified over the extended -40C to
+85C temperature range.
Applications
Features
Filterless Class D Amplifier
Unique Spread-Spectrum Mode Offers 5dB
Emissions Improvement Over Conventional
Methods
Up to 78% Efficient (R
L
= 8
)
Up to 88% Efficient (R
L
= 16
)
15W Continuous Output Power into 8 (MAX9703)
2x10W Continuous Output Power into 8 (MAX9704)
Low 0.07% THD+N
High PSRR (80dB at 1kHz)
10V to 25V Single-Supply Operation
Differential Inputs Minimize Common-Mode Noise
Pin-Selectable Gain Reduces Component Count
Industry-Leading Click-and-Pop Suppression
Low Quiescent Current (24mA)
Low-Power Shutdown Mode (0.2A)
Short-Circuit and Thermal-Overload Protection
Available in Thermally Efficient, Space-Saving
Packages
32-Pin TQFN (5mm x 5mm x 0.8mm)MAX9703
32-Pin TQFN (7mm x 7mm x 0.8mm)MAX9704
MAX9703/MAX9704
10W Stereo/15W Mono, Filterless,
Spread-Spectrum, Class D Amplifiers
________________________________________________________________ Maxim Integrated Products
1
19-3160; Rev 7; 3/06
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.
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
AMP
MAX9703ETJ+
-40
o
C to +85
o
C
32 TQFN-EP*
Mono
MAX9704ETJ+
-40
o
C to +85
o
C
32 TQFN-EP*
Stereo
*EP = Exposed paddle.
+Denotes lead-free package.
LCD TVs
LCD Monitors
Desktop PCs
LCD Projectors
Hands-Free Car
Phone Adaptors
Automotive
Pin Configurations appear at end of data sheet.
MAX9704
0.47
F
INL+
OUTL+
OUTL-
INL-
0.47
F
H-BRIDGE
0.47
F
INR+
OUTR+
OUTR-
INR-
0.47
F
H-BRIDGE
MAX9703
0.47
F
IN+
OUT+
OUT-
IN-
0.47
F
H-BRIDGE
Block Diagrams
MAX9703/MAX9704
10W Stereo/15W Mono, Filterless,
Spread-Spectrum, Class D Amplifiers
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
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.
(All voltages referenced to GND.)
V
DD
to PGND, AGND .............................................................30V
OUTR_, OUTL_, C1N..................................-0.3V to (V
DD
+ 0.3V)
C1P............................................(V
DD
- 0.3V) to (CHOLD + 0.3V)
CHOLD ........................................................(V
DD
- 0.3V) to +40V
All Other Pins to GND.............................................-0.3V to +12V
Duration of OUTR_/OUTL_
Short Circuit to GND, V
DD
..................................................10s
Continuous Input Current (V
DD
, PGND) ...............................1.6A
Continuous Input Current......................................................0.8A
Continuous Input Current (all other pins)..........................
20mA
Continuous Power Dissipation (T
A
= +70C)
Single-Layer Board:
MAX9703 32-Pin TQFN (derate 21.3mW/C
above +70C)..........................................................1702.1mW
MAX9704 32-Pin TQFN (derate 27mW/C
above +70C)..........................................................2162.2mW
Multilayer Board:
MAX9703 32-Pin TQFN (derate 34.5mW/C
above +70C)..........................................................2758.6mW
MAX9704 32-Pin TQFN (derate 37mW/C
above +70C)..........................................................2963.0mW
Junction Temperature ......................................................+150C
Operating Temperature Range ...........................-40C to +85C
Storage Temperature Range .............................-65C to +150C
Lead Temperature (soldering, 10s) .................................+300C
ELECTRICAL CHARACTERISTICS
(V
DD
= 15V, GND = PGND = 0V,
SHDN
V
IH
, A
V
= 16dB, C
SS
= C
IN
= 0.47F, C
REG
= 0.01F, C1 = 100nF, C2 = 1F, FS1 = FS2 =
GND (f
S
= 660kHz), R
L
connected between OUTL+ and OUTL- and OUTR+ and OUTR-, T
A
= T
MIN
to T
MAX
, unless otherwise noted.
Typical values are at T
A
= +25C.) (Notes 1, 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
GENERAL
Supply Voltage Range
V
DD
Inferred from PSRR test
10
25
V
MAX9703
14
22
Quiescent Current
I
DD
R
L
= OPEN
MAX9704
24
34
mA
Shutdown Current
I
SHDN
0.2
1.5
A
C
SS
= 470nF
100
Turn-On Time
t
ON
C
SS
= 180nF
50
ms
Amplifier Output Resistance in
Shutdown
SHDN = GND
150
330
k
A
V
= 13dB
35
58
80
A
V
= 16dB
30
48
65
A
V
= 19.1dB
23
39
55
Input Impedance
R
IN
A
V
= 29.6dB
10
15
22
k
G1 = L, G2 = L
29.4
29.6
29.8
G1 = L, G2 = H
18.9
19.1
19.3
G1 = H, G2 = L
12.8
13
13.2
Voltage Gain
A
V
G1 = H, G2 = H
15.9
16
16.3
dB
Gain Matching
Between channels (MAX9704)
0.5
%
Output Offset Voltage
V
OS
6
30
mV
Common-Mode Rejection Ratio
CMRR
f
IN
= 1kHz, input referred
60
dB
V
DD
= 10V to 25V
54
80
f
RIPPLE
= 1kHz
80
Power-Supply Rejection Ratio
(Note 3)
PSRR
200mV
P-P
ripple
f
RIPPLE
= 20kHz
66
dB
MAX9703/MAX9704
10W Stereo/15W Mono, Filterless,
Spread-Spectrum, Class D Amplifiers
_______________________________________________________________________________________
3
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= 15V, GND = PGND = 0V, SHDN
V
IH
, A
V
= 16dB, C
SS
= C
IN
= 0.47F, C
REG
= 0.01F, C1 = 100nF, C2 = 1F, FS1 = FS2 =
GND (f
S
= 660kHz), R
L
connected between OUTL+ and OUTL- and OUTR+ and OUTR-, T
A
= T
MIN
to T
MAX
, unless otherwise noted.
Typical values are at T
A
= +25C.) (Notes 1, 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
R
L
= 4
10
R
L
= 8
15
Continuous Output Power
(MAX9703)
P
CONT
TH D + N = 10%, V
DD
=
16V, f = 1kH z, T
A
=
+ 25C , t
CONT
= 15min
(Note 4)
R
L
= 16
, V
DD
= 24V
18
W
R
L
= 4
2x5
R
L
= 8
2x10
Continuous Output Power
(MAX9704)
P
CONT
TH D + N = 10%, V
DD
=
16V, f = 1kH z, T
A
=
+ 25C , t
CONT
= 15min
(Note 4)
R
L
= 16
, V
DD
= 24V
2x16
W
Total Harmonic Distortion Plus
Noise
THD+N
f
IN
= 1kHz, either FFM or SSM, R
L
= 8
,
P
OUT
= 4W
0.07
%
FFM
94
BW = 22Hz to
22kHz
SSM
88
FFM
97
Signal-to-Noise Ratio
SNR
R
L
= 8
, P
OUT
=
10W, f = 1kHz
A-weighted
SSM
91
dB
Crosstalk
Left to right, right to left, 8
load, f
IN
= 10kHz
65
dB
FS1 = L, FS2 = L
560
670
800
FS1 = L, FS2 = H
940
FS1 = H, FS2 = L
470
Oscillator Frequency
f
OSC
FS1 = H, FS2 = H (spread-spectrum mode)
670
7%
kHz
P
OUT
= 15W, f = 1kHz, R
L
= 8
78
Efficiency
P
OUT
= 10W, f = 1kHz, R
L
= 16
88
%
Regulator Output
V
REG
6
V
DIGITAL INPUTS (
SHDN, FS_, G_)
V
IH
2.5
Input Thresholds
V
IL
0.8
V
Input Leakage Current
1
A
Note 1: All devices are 100% production tested at +25C. All temperature limits are guaranteed by design.
Note 2: Testing performed with a resistive load in series with an inductor to simulate an actual speaker load. For R
L
= 8
, L = 68H.
For R
L
= 4
, L = 33H.
Note 3: PSRR is specified with the amplifier inputs connected to GND through C
IN
.
Note 4: The MAX9704 continuous 8
and 16 power measurements account for thermal limitations of the 32-pin TQFN-EP package.
Continuous 4
power measurements account for short-circuit protection of the MAX9703/MAX9704 devices.
MAX9703/MAX9704
10W Stereo/15W Mono, Filterless,
Spread-Spectrum, Class D Amplifiers
4
_______________________________________________________________________________________
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCY
MAX9703/04 toc01
FREQUENCY (Hz)
THD+N (%)
10k
1k
100
0.1
1
10
0.01
10
100k
V
DD
= 15V
R
L
= 4
A
V
= 16dB
P
OUT
= 4W
P
OUT
= 500mW
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCY
MAX9703/04 toc02
FREQUENCY (Hz)
THD+N (%)
10k
1k
100
0.1
1
10
0.01
10
100k
V
DD
= 15V
R
L
= 8
A
V
= 16dB
P
OUT
= 500mW
P
OUT
= 8W
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCY
MAX9703/04 toc03
FREQUENCY (Hz)
THD+N (%)
10k
1k
100
0.1
1
10
0.01
10
100k
V
DD
= 20V
R
L
= 8
A
V
= 16dB
P
OUT
= 8W
P
OUT
= 500mW
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCY
MAX9703/04 toc04
FREQUENCY (Hz)
THD+N (%)
10k
1k
100
0.1
1
10
0.01
10
100k
V
DD
= 20V
R
L
= 8
A
V
= 16dB
P
OUT
= 8W
SSM
FFM
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. OUTPUT POWER
MAX9703/04 toc07
OUTPUT POWER (W)
THD+N (%)
4
2
6
8
10 12 14 16 18
0.1
1
10
100
0.01
0
20
V
DD
= 20V
R
L
= 8
A
V
= 16dB
f = 100Hz
f = 1kHz
f = 10kHz
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. OUTPUT POWER
MAX9703/04 toc05
OUTPUT POWER (W)
THD+N (%)
6
4
5
2
3
1
0.1
1
10
100
0.01
0
10
9
7
8
V
DD
= 15V
R
L
= 4
A
V
= 16dB
f = 10kHz
f = 1kHz
f = 100Hz
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. OUTPUT POWER
MAX9703/04 toc06
OUTPUT POWER (W)
THD+N (%)
1 2 3 4 5 6 7 8 9 10 11 12 13 14
0.1
1
10
0.01
0
15
V
DD
= 15V
R
L
= 8
A
V
= 16dB
f = 100Hz
f = 1kHz
f = 10kHz
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. OUTPUT POWER
MAX9703/04 toc08
OUTPUT POWER (W)
THD+N (%)
1 2 3 4 5 6 7 8 9 10111213141516171819
0.1
1
10
0.01
0
20
FFM (335kHz)
SSM
V
DD
= 20V
R
L
= 8
A
V
= 16dB
f = 1kHz
EFFICIENCY vs. OUTPUT POWER
MAX9703/04 toc09
OUTPUT POWER (W)
EFFICIENCY (%)
8
6
4
2
3
5
7
9
1
10
20
30
40
50
60
70
80
90
100
0
0
10
V
DD
= 12V
A
V
= 16dB
f = 1kHz
R
L
= 4
R
L
= 8
Typical Operating Characteristics
(33H with 4
, 68H with 8, part in SSM mode, 136H with 16, measurement BW = 22Hz to 22kHz, unless otherwise noted.)
MAX9703/MAX9704
10W Stereo/15W Mono, Filterless,
Spread-Spectrum, Class D Amplifiers
_______________________________________________________________________________________
5
EFFICIENCY vs. OUTPUT POWER
MAX9703/04 toc10
OUTPUT POWER (W)
EFFICIENCY (%)
16
12
8
4
2
6
10
14
18
10
20
30
40
50
60
70
80
90
100
0
0
20
V
DD
= 15V
A
V
= 16dB
f = 1kHz
R
L
= 16
R
L
= 8
OUTPUT POWER
vs. SUPPLY VOLTAGE
MAX9703/04 toc11
SUPPLY VOLTAGE (V)
OUTPUT POWER (W)
0
6
4
2
8
10
12
14
16
18
20
10
16
13
19
22
25
R
L
= 8
R
L
= 16
A
V
= 16dB
THD+N = 10%
20
18
16
14
12
10
8
6
4
2
0
1
10
100
OUTPUT POWER
vs. LOAD RESISTANCE
MAX9703/04 toc12
LOAD RESISTANCE (
)
OUTPUT POWER (W)
THD+N = 1%
THD+N = 10%
V
DD
= 15V
A
V
= 16dB
24
22
20
18
16
14
12
10
8
6
4
2
0
1
10
100
OUTPUT POWER
vs. LOAD RESISTANCE
MAX9703/04 toc13
LOAD RESISTANCE (
)
OUTPUT POWER (W)
V
DD
= 20V
A
V
= 16dB
THD+N = 10%
THD+N = 1%
CROSSTALK vs. FREQUENCY
MAX9703/04 toc16
FREQUENCY (Hz)
CROSSTALK (dB)
10k
1k
100
-80
-100
-60
-40
-20
0
-120
10
100k
LEFT TO RIGHT
RIGHT TO LEFT
A
V
= 16dB
1% THD+N
V
DD
= 15V
8
LOAD
COMMON-MODE REJECTION RATIO
vs. FREQUENCY
MAX9703/04 toc14
FREQUENCY (Hz)
CMRR (dB)
10k
1k
100
-70
-60
-50
-40
-30
-20
-10
0
-80
10
100k
V
DD
= 15V
R
L
= 8
A
V
= 16dB
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
MAX9703/04 toc15
FREQUENCY (Hz)
PSRR (dB)
10k
1k
100
-100
-80
-60
-40
-20
0
-120
10
100k
A
V
= 16dB
R
L
= 8
200mV
P-P
INPUT
V
DD
= 15V
OUTPUT FREQUENCY SPECTRUM
MAX9703/04 toc17
FREQUENCY (kHz)
OUTPUT MAGNITUDE (dB)
-120
-100
-80
-60
-40
-20
0
20
-140
18
16
12 14
4
6
8
10
2
0
20
FFM MODE
A
V
= 16dB
UNWEIGHTED
f
IN
= 1kHz
P
OUT
= 5W
R
L
= 8
OUTPUT FREQUENCY SPECTRUM
MAX9703/04 toc18
FREQUENCY (kHz)
OUTPUT MAGNITUDE (dB)
-120
-100
-80
-60
-40
-20
0
20
-140
18
16
12 14
4
6
8
10
2
0
20
SSM MODE
A
V
= 16dB
UNWEIGHTED
f
IN
= 1kHz
P
OUT
= 5W
R
L
= 8
Typical Operating Characteristics (continued)
(33H with 4
, 68H with 8, part in SSM mode, 136H with 16, measurement BW = 22Hz to 22kHz, unless otherwise noted.)
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