MAX9710ETP+T [MAXIM]
Audio Amplifier, 3W, 2 Channel(s), 1 Func, BICMOS, 5 X 5 MM, 0.80 MM HEIGHT, EXPOSED PAD, QFN-20;
| 型号： | MAX9710ETP+T |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Audio Amplifier, 3W, 2 Channel(s), 1 Func, BICMOS, 5 X 5 MM, 0.80 MM HEIGHT, EXPOSED PAD, QFN-20 放大器 功率放大器 |
| 文件： | 总13页 (文件大小：299K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-2841; Rev 1; 6/08
3W Mono/Stereo BTL Audio Power Amplifiers
with Shutdown
0/MAX971
General Description
Features
The MAX9710/MAX9711 are stereo/mono 3W bridge-tied
load (BTL) audio power amplifiers. These devices are
PC99/01 compliant, operate from a single 4.5V to 5.5V
supply, and feature an industry-leading 100dB PSRR,
which allows these devices to operate from noisy sup-
plies without additional, costly power-supply condition-
ing. An ultra-low 0.005% THD+N ensures clean,
low-distortion amplification of the audio signal while
click-and-pop suppression eliminates audible transients
on power and shutdown cycles. Power-saving features
♦ 3W into 3Ω (1% THD+N)
♦ 4W into 3Ω (10% THD+N)
♦ Industry-Leading, Ultra-High 100dB PSRR
♦ PC99/01 Compliant
♦ Click-and-Pop Suppression
♦ Low 0.005% THD+N
♦ Low Quiescent Current: 7mA
♦ Low-Power Shutdown Mode: 0.5µA
♦ MUTE Function
include low 2mV V
(minimizing DC current drain
OS
through the speakers), low 7mA supply current, and a
0.5µA shutdown mode. A MUTE function allows the out-
puts to be quickly enabled or disabled.
♦ Tiny 20-Pin Thin QFN (5mm ✕ 5mm ✕ 0.8mm)
These devices include thermal overload protection, are
specified over the extended -40°C to +85°C tempera-
ture range, and are supplied in thermally efficient pack-
ages. The MAX9710 is available in a 20-pin thin QFN
package (5mm ✕ 5mm ✕ 0.8mm). The MAX9711 is
available in a 12-pin thin QFN package (4mm ✕ 4mm ✕
0.8mm).
Ordering Information
PART
TEMP RANGE PIN-PACKAGE
AMP
20-Thin QFN-EP* Stereo
12-Thin QFN-EP* Mono
MAX9710ETP -40°C to +85°C
MAX9711ETC -40°C to +85°C
*EP = Exposed pad.
Applications
Notebook PCs
Two-Way Radios
Flat-Panel TVs
General-Purpose Audio
Powered Speakers
Flat-Panel PC Displays
Simplified Block Diagram
Pin Configurations
TOP VIEW
SINGLE SUPPLY
4.5V TO 5.5V
20
19
18
17
16
LEFT IN
15 PGND
14 SHDN
13 N.C.
INL
BIAS
N.C.
1
2
3
4
5
MAX9710
MAX9710
12
V
DD
MUTE
INR
RIGHT IN
11 PGND
6
7
8
9
10
TQFN
Pin Configurations continued at end of data sheet.
________________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
3W Mono/Stereo BTL Audio Power Amplifiers
with Shutdown
ABSOLUTE MAXIMUM RATINGS
V
DD
to GND, PGND ...............................................................+6V
20-Pin Thin QFN (derate 20.8mW/°C above +70°C) ....1667mW
Operating Temperature Range............................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Junction Temperature......................................................+150°C
Lead Temperature (soldering, 10s) .................................+ꢀ00°C
PV
to V
....................................................................... 0.ꢀV
DD
DD
PGND to GND..................................................................... 0.ꢀV
All Other Pins to GND.................................-0.ꢀV to (V
Continuous Input Current (into any pin
+ 0.ꢀV)
DD
except power supply and output pins)......................... 20mA
Continuous Power Dissipation (T = +70°C)
A
12-Pin Thin QFN (derate 16.9mW/°C above +70°C) ....1ꢀ49mW
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.
ELECTRICAL CHARACTERISTICS
(V
= PV
= 5.0V, V
= V
= V
= 0V, V
= 5V, R = R = 15kΩ, R = ∞. T = T
to T
, unless otherwise
MAX
DD
DD
GND
PGND
MUTE
SHDN
IN
F
L
A
MIN
noted. Typical values are at T = +25°C.) (Note 1)
A
PARAMETER
Supply Voltage Range
Quiescent Supply Current
SYMBOL
CONDITIONS
MIN
TYP
MAX
5.5
ꢀ0
UNITS
V
/PV
Inferred from PSRR test
MAX9710
4.5
V
DD
DD
12
7
0/MAX971
I
mA
µA
DD
(I
+ I
)
VDD
PVDD
MAX9711
17
Shutdown Supply Current
I
SHDN = GND
0.5
ꢀ00
ꢀ0
ꢀ0
SHDN
C
C
= 1µF (10% of final value)
= 0.1µF (10% of final value)
BIAS
BIAS
Turn-On Time
t
ms
ON
Thermal Shutdown Threshold
Thermal Shutdown Hysteresis
OUTPUT AMPLIFIERS
160
15
°C
°C
Output Offset Voltage
V
V
V
- V , A = 2
OUT_- V
2
100
87
14
mV
dB
OS
OUT_+
RIPPLE
V
= 4.5V to 5.5V
82
DD
= 200mV
P-P
f = 1kHz
Power-Supply Rejection Ratio
Output Power
PSRR
(Note 2)
f = 20kHz
74
R = 8Ω
1.1
1.4
2.6
ꢀ
L
f
IN
= 1kHz,
P
R = 4Ω
W
%
OUT
L
THD+N < 1%
R = ꢀΩ
L
P
P
= 1.2W, R = 8Ω
0.005
0.01
95
Total Harmonic Distortion Plus
Noise
f
IN
= 1kHz, BW =
OUT
OUT
L
THD+N
22Hz to 22kHz
= 2W, 4Ω
Signal-to-Noise Ratio
Slew Rate
SNR
SR
R = 8Ω, V
= 2.8V
, BW = 22Hz to 22kHz
dB
V/µs
nF
L
OUT
RMS
1.6
1
Maximum Capacitive Load Drive
Crosstalk
C
No sustained oscillations
= 10kHz
L
f
77
dB
IN
BIAS VOLTAGE (BIAS)
BIAS Voltage
V
R
2.ꢀ5
2
2.5
50
2.65
V
BIAS
Output Resistance
DIGITAL INPUTS (MUTE, SHDN)
Input Voltage High
Input Voltage Low
kΩ
BIAS
V
V
V
IH
V
0.8
1
IL
Input Leakage Current
I
IN
µA
Note 1: All devices are 100% production tested at +25°C. All temperature limits are guaranteed by design.
Note 2: PSSR is specified with the amplifier inputs connected to GND through R and C
.
IN
IN
2
_______________________________________________________________________________________
3W Mono/Stereo BTL Audio Power Amplifiers
with Shutdown
0/MAX971
Typical Operating Characteristics
(V
DD
= 5V, THD+N measurement bandwidth = 22Hz to 22kHz, T = +25°C, unless otherwise noted.)
A
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY
1
1
1
R = 3Ω
R = 4Ω
L
R = 3Ω
L
A
L
A
= -4V/V
A = -2V/V
V
= -2V/V
V
V
0.1
0.01
0.1
0.01
0.1
P
OUT
= 500mW
P
OUT
= 500mW
P
= 250mW
OUT
0.01
P
OUT
= 2.5W
1k
P
= 2.5W
1k
OUT
P
OUT
= 2W
1k
0.001
0.001
0.001
10
100
10k
100k
10
100
10k
100k
10
100
10k
100k
FREQUENCY (Hz)
FREQUENCY (Hz)
FREQUENCY (Hz)
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY
1
1
1
R = 4Ω
R = 8Ω
L
R = 8Ω
L
A
L
A
= -4V/V
A = -4V/V
V
= -2V/V
V
V
0.1
0.01
0.1
0.01
0.1
0.01
P
OUT
= 250mW
P
= 250mW
OUT
P
= 250mW
OUT
P
OUT
= 2W
P
OUT
= 1.2W
1k
P
OUT
= 1.2W
1k
0.001
0.001
0.001
10
100
1k
FREQUENCY (Hz)
10k
100k
10
100
10k
100k
10
100
10k
100k
FREQUENCY (Hz)
FREQUENCY (Hz)
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER
100
100
100
A
= -2V/V
A
= -4V/V
A = -2V/V
V
R = 4Ω
L
V
L
V
R = 3Ω
R = 3Ω
L
10
10
10
1
1
1
f = 10kHz
f = 10kHz
f = 1kHz
f = 10kHz
f = 20Hz
0.1
0.1
0.1
f = 1kHz
0.01
0.001
0.01
0.001
0.01
0.001
f = 20Hz
f = 1kHz
f = 20Hz
0
1
2
3
4
0
1
2
3
4
0
0.5 1.0 1.5 2.0 2.5 3.0 3.5
OUTPUT POWER (W)
OUTPUT POWER (W)
OUTPUT POWER (W)
_______________________________________________________________________________________
3
3W Mono/Stereo BTL Audio Power Amplifiers
with Shutdown
Typical Operating Characteristics (continued)
(V
DD
= 5V, THD+N measurement bandwidth = 22Hz to 22kHz, T = +25°C, unless otherwise noted.)
A
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER
100
100
100
A
V
= -4V/V
A
V
= -2V/V
A = -4V/V
V
R = 4Ω
L
R = 8Ω
L
R = 8Ω
L
10
10
10
1
1
1
f = 10kHz
f = 10kHz
f = 1kHz
0.1
0.01
0.1
0.1
f = 1kHz
f = 10kHz
f = 1kHz
0.01
0.001
0.01
0.001
f = 20Hz
0.5
f = 20Hz
f = 20Hz
0.5
0.001
0
0.5 1.0 1.5 2.0 2.5 3.0 3.5
OUTPUT POWER (W)
0
1.0
1.5
2.0
0
1.0
1.5
2.0
0/MAX971
OUTPUT POWER (W)
OUTPUT POWER (W)
OUTPUT POWER
vs. TEMPERATURE
OUTPUT POWER
vs. TEMPERATURE
OUTPUT POWER
vs. TEMPERATURE
4
4
3
2
1
0
2.0
1.5
1.0
0.5
0
THD+N = 10%
THD+N = 10%
THD+N = 1%
THD+N = 10%
3
2
1
0
THD+N = 1%
THD+N = 1%
f = 1kHz
R = 3Ω
f = 1kHz
R = 4Ω
f = 1kHz
R = 8Ω
L
L
L
-40
-15
10
35
60
85
-40
-15
10
35
60
85
-40
-15
10
35
60
85
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
OUTPUT POWER vs. LOAD RESISTANCE
(FORCED-AIR COOLING)
POWER DISSIPATION
vs. OUTPUT POWER
POWER DISSIPATION
vs. OUTPUT POWER
5
4
3
2
1
0
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
V
= 5V
DD
f = 1kHz
THD+N = 10%
THD+N = 1%
R = 4Ω
R = 8Ω
L
L
f = 1kHz
f = 1kHz
1
10
100
1000
0
0.5
1.0
1.5
2.0
2.5
0
0.25 0.50 0.75 1.00 1.25 1.50
OUTPUT POWER (W)
LOAD RESISTANCE (Ω)
OUTPUT POWER (W)
4
_______________________________________________________________________________________
3W Mono/Stereo BTL Audio Power Amplifiers
with Shutdown
0/MAX971
Typical Operating Characteristics (continued)
(V
DD
= 5V, THD+N measurement bandwidth = 22Hz to 22kHz, T = +25°C, unless otherwise noted.)
A
POWER-SUPPLY REJECTION RATIO
CROSSTALK vs. FREQUENCY
vs. FREQUENCY
0
-20
0
-20
V
= 200mV
P-P
IN
V
= 200mV
P-P
RIPPLE
R = 8Ω
L
-40
-40
-60
RIGHT TO LEFT
-60
-80
-80
-100
-120
LEFT TO RIGHT
-100
0.01
0.1
1
10
100
10
100
1k
FREQUENCY (Hz)
10k
100k
FREQUENCY (Hz)
ENTERING SHUTDOWN
EXITING SHUTDOWN
MAX9710/11 toc21
MAX9710/11 toc22
2V/div
2V/div
SHDN
SHDN
OUT_+ AND
OUT_-
OUT_+ AND
OUT_-
1V/div
1V/div
OUT_+ -
OUT_-
OUT_+ -
OUT_-
200mV/div
200mV/div
100ms/div
INPUT AC-COUPLED TO GND
100ms/div
R = 8Ω
R = 8Ω
L
L
INPUT AC-COUPLED TO GND
ENTERING POWER-DOWN
EXITING POWER-DOWN
MAX9710/11 toc24
MAX9710/11 toc23
2V/div
2V/div
V
V
DD
DD
OUT_+ AND
OUT_-
OUT_+ AND
OUT_-
1V/div
1V/div
OUT_+ -
OUT_-
OUT_+ -
OUT_-
200mV/div
200mV/div
100ms/div
100ms/div
R = 8Ω
R = 8Ω
L
L
INPUT AC-COUPLED TO GND
INPUT AC-COUPLED TO GND
_______________________________________________________________________________________
5
3W Mono/Stereo BTL Audio Power Amplifiers
with Shutdown
Typical Operating Characteristics (continued)
(V
DD
= 5V, THD+N measurement bandwidth = 22Hz to 22kHz, T = +25°C, unless otherwise noted.)
A
MAX9710
MAX9711
SHUTDOWN SUPPLY CURRENT
vs. SUPPLY VOLTAGE
SUPPLY CURRENT vs. SUPPLY VOLTAGE
SUPPLY CURRENT vs. SUPPLY VOLTAGE
18
16
14
12
10
8
12
10
8
1.0
0.8
0.6
0.4
0.2
0
T
= +25°C
A
T
= +85°C
A
T
= +25°C
A
A
T
A
= +85°C
T
A
= +25°C
T
A
= +85°C
6
T
A
= -40°C
6
4
T
= -40°C
T
A
= -40°C
4
2
2
0
0
4.50
4.75
5.00
5.25
5.50
4.50
4.75
5.00
5.25
5.50
4.50
4.75
5.00
5.25
5.50
0/MAX971
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
Pin Description
PIN
NAME
FUNCTION
MAX9710
MAX9711
1
—
7
INL
BIAS
Left-Channel Input
2
DC Bias Bypass. See BIAS Capacitor section for capacitor selection.
No Connection. Not internally connected.
Active-High Mute Input
3, 10, 13, 16
—
9
N.C.
4
MUTE
INR
5
—
1, 3
—
5, 11
—
8
Right-Channel Input
6, 11, 15, 20
PGND
OUTR+
Power Ground
7
8, 18
9
Right-Channel Bridged Amplifier Positive Output
Output Amplifier Power Supply
PV
DD
OUTR-
Right-Channel Bridged Amplifier Negative Output
Power Supply
12
14
17
19
—
V
DD
10
—
—
2
SHDN
OUTL-
OUTL+
IN
Active-Low Shutdown. Connect SHDN to V
for normal operation.
DD
Left-Channel Bridged Amplifier Negative Output
Left-Channel Bridged Amplifier Positive Output
Amplifier Input
—
6
GND
OUT-
OUT+
EP
Ground
—
12
4
Bridged Amplifier Negative Output
Bridged Amplifier Positive Output
Exposed Pad. Connect to ground plane.
—
—
—
6
_______________________________________________________________________________________
3W Mono/Stereo BTL Audio Power Amplifiers
with Shutdown
0/MAX971
Detailed Description
The MAX9710/MAX9711 are 3W BTL speaker ampli-
fiers. The MAX9710 is a stereo speaker amplifier, while
V
+1
OUT(P-P)
the MAX9711 is a mono speaker amplifier. Both
devices feature a low-power shutdown mode, MUTE
mode, and comprehensive click-and-pop suppression.
These devices consist of high output-current op amps
configured as BTL amplifiers (see Functional
Diagrams). The device gain is set by R and R .
2 x V
V
OUT(P-P)
-1
OUT(P-P)
F
IN
BIAS
These devices operate from a single 5V supply and
feature an internally generated, power-supply-indepen-
dent, common-mode bias voltage of 2.5V referenced to
ground. BIAS provides both click-and-pop suppression
and sets the DC bias level for the audio outputs. BIAS
is internally connected to the noninverting input of each
speaker amplifier (see Functional Diagrams). Choose
the value of the bypass capacitor as described in the
BIAS Capacitor section. No external load should be
applied to BIAS. Any load lowers the BIAS voltage,
affecting the overall performance of the device.
Figure 1. Bridge-Tied Load Configuration
Applications Information
BTL Amplifier
The MAX9710/MAX9711 are designed to drive a load
differentially, a configuration referred to as BTL. The
BTL configuration (Figure 1) offers advantages over the
single-ended configuration, where one side of the load
is connected to ground. Driving the load differentially
doubles the output voltage compared to a single-
ended amplifier under similar conditions. Thus, the dif-
ferential gain of the device is twice the closed-loop gain
of the input amplifier. The effective gain is given by:
Shutdown
The MAX9710/MAX9711 feature a 0.5µA low-power shut-
down mode that reduces quiescent current consump-
tion. Pulling SHDN low disables the device’s bias
circuitry, the amplifier outputs are actively pulled low,
R
F
A
= 2×
VD
and BIAS is driven to GND. Connect SHDN to V
for
DD
R
IN
normal operation.
MUTE
Both devices feature a clickless/popless MUTE mode.
When the device is muted, the input disconnects from
the amplifier. MUTE only affects the power amplifiers
and does not shut down the device. Drive MUTE high to
mute the device. Drive MUTE low for normal operation.
Substituting 2 x V
ing equations yields four times the output power due to
doubling of the output voltage:
for V
into the follow-
OUT(P-P)
OUT(P-P)
V
OUT(P−P)
V
=
RMS
2 2
Click-and-Pop Suppression
The MAX9710/MAX9711 feature Maxim’s comprehen-
sive click-and-pop suppression. During startup, the
common-mode bias voltage of the amplifiers slowly
ramps to the DC bias point using an S-shaped wave-
form. When entering shutdown, the amplifier outputs are
actively driven low simultaneously. This scheme mini-
mizes the energy present in the audio band.
2
V
RMS
P
=
OUT
R
L
Since the differential outputs are biased at midsupply,
there is no net DC voltage across the load. This elimi-
nates the need for DC-blocking capacitors required for
single-ended amplifiers. These capacitors can be
large, expensive, consume board space, and degrade
low-frequency performance.
For optimum click-and-pop suppression, choose:
R
IN
x C < R
x C
BIAS BIAS
IN
where R
= 50kΩ.
BIAS
_______________________________________________________________________________________
7
3W Mono/Stereo BTL Audio Power Amplifiers
with Shutdown
Input Filter
The input capacitor (C ), in conjunction with R , forms
a highpass filter that removes the DC bias from an
incoming signal. The AC-coupling capacitor allows the
amplifier to bias the signal to an optimum DC level.
Assuming zero-source impedance, the -3dB point of
the highpass filter is given by:
Power Dissipation and Heat Sinking
Under normal operating conditions, the MAX9710/
MAX9711 dissipate a significant amount of power. The
maximum power dissipation for each package is given
in the Absolute Maximum Ratings section under
Continuous Power Dissipation or can be calculated by
the following equation:
IN
IN
1
f −3dB
=
T
− T
A
J(MAX)
2πR C
P
=
IN IN
DISSPKG(MAX)
θ
JA
For optimum click-and-pop suppression, choose:
x C < R x C
where T
) is +150°C, T is the ambient temperature,
A
J(MAX
and θ is the reciprocal of the derating factor in °C/W as
JA
R
IN
IN
BIAS
BIAS
specified in the Absolute Maximum Ratings section. For
example, θ
48.1°C/W.
where R
= 50kΩ.
BIAS
of the 20-pin thin QFN package is
JA
Setting f
too high affects the low-frequency
-3dB
response of the amplifier. Use capacitors with
dielectrics that have low-voltage coefficients, such as
tantalum or aluminum electrolytic. Capacitors with high-
voltage coefficients, such as ceramics, may result in an
increase of distortion at low frequencies.
The increase in power delivered by the BTL configura-
tion directly results in an increase in internal power dis-
sipation over the single-ended configuration. The
0/MAX971
maximum power dissipation for a given V
given by the following equation:
and load is
DD
BIAS Capacitor
2
2V
DD
BIAS is the output of the internally generated 2.5VDC
P
=
DISS(MAX)
2
bias voltage. The BIAS bypass capacitor, C
,
BIAS
π R
L
improves PSRR and THD+N by reducing power supply
and other noise sources at the common-mode bias
node, and also generates the clickless/popless startup
DC bias waveform for the speaker amplifiers. Bypass
BIAS with a 1µF capacitor to GND. Smaller values of
If the power dissipation for a given application exceeds
the maximum allowed for a given package, either reduce
V
, increase load impedance, decrease the ambient
DD
temperature, or add heat sinking to the device (see
Layout and Grounding section). Large output, supply,
and ground PC board traces improve the maximum
power dissipation in the package.
C
BIAS
produce faster t /t
times but may result in
ON OFF
increased click/pop levels.
Supply Bypassing
Thermal-overload protection limits total power dissipa-
tion in the MAX9710/MAX9711. When the junction
temperature exceeds +160°C, the thermal protection
circuitry disables the amplifier output stage. The
amplifiers are enabled once the junction temperature
cools by 15°C. A pulsing output under continuous
thermal-overload conditions results as the device heats
and cools.
Proper power-supply bypassing ensures low-noise,
low-distortion performance. Place a 0.1µF ceramic
capacitor from V
to PGND. Add additional bulk
DD
capacitance as required by the application. Locate the
bypass capacitor as close to the device as possible.
Piezoelectric Speaker Driver
Low-profile piezoelectric speakers can provide quality
sound for portable electronics. However, piezoelectric
speakers typically require large voltage swings
Component Selection
(>8V
) across the speaker element to produce
Gain-Setting Resistors
P-P
audible sound pressure levels. The MAX9711 can be
configured to drive a piezoelectric speaker with up to
External feedback components set the gain of both
devices. Resistors R and R (Functional Diagrams)
F
IN
10V
while operating from a single 5V supply.
set the gain of the amplifier as follows:
P-P
Figure 2 shows the THD+N of the MAX9711 driving a
piezoelectric speaker. Note that as frequency increas-
es, the THD+N increases. This is due to the capacitive
nature of the piezoelectric speaker; as frequency
increases, the speaker impedance decreases, resulting
in a larger current draw from the amplifier.
R
R
F
A
= 2 ×
VD
IN
8
_______________________________________________________________________________________
3W Mono/Stereo BTL Audio Power Amplifiers
with Shutdown
0/MAX971
TOTAL HARMONIC DISTORTI0N PLUS NOISE
15kΩ
vs. FREQUENCY
10
1μF
15kΩ
V
OUT
= 8V
P-P
2
IN
AUDIO
INPUT
10Ω
4
OUT+
1
0.1
100μH
*
0.01
0.001
12
OUT-
*PIEZOELECTRIC
SPEAKER.
0.01
0.1
1
10
100
MAX9711
FREQUENCY (Hz)
Figure 2. MAX9711 Piezoelectric Speaker Driver THD+N vs.
Frequency
Figure 3. Isolation Network for Driving a Piezoelectric Speaker
The capacitive nature of the piezoelectric speaker may
cause the MAX9711 to become unstable. A simple induc-
tor/resistor network in series with the speaker isolates the
speaker capacitance from the driver and ensures that the
device output sees a resistive load of about 10Ω at high
frequency, thereby maintaining stability (Figure 3).
5V
PV
V
DD
DD
Layout and Grounding
Good PC board layout is essential for optimizing perfor-
mance. Use large traces for the power-supply inputs and
amplifier outputs to minimize losses due to parasitic
trace resistance and route heat away from the device.
Good grounding improves audio performance,
minimizes crosstalk between channels, and prevents any
digital switching noise from coupling into the audio
signal.
MAX9710
FOR OPTIMUM PERFORMANCE,
AUDIO GND SHOULD HAVE A
STAR CONNECTION TO THE HIGH
CURRENT, AMPLIFIER PGND AT
A SINGLE POINT, PIN 6.
The MAX9710/MAX9711 thin QFN package features an
exposed thermal pad on the underside. This pad low-
ers the thermal resistance of the package by providing
a direct-heat conduction path from the die to the print-
ed circuit board. Connect the exposed pad to the
ground plane using multiple vias, if required. For opti-
mum performance, connect to the ground planes as
shown in Figure 4.
PGND
AUDIO SIGNAL
GND
Figure 4. MAX9710 Audio Ground Connection
_______________________________________________________________________________________
9
3W Mono/Stereo BTL Audio Power Amplifiers
with Shutdown
Functional Diagrams
R
F
15kΩ
C
0.1μF
IN
R
IN
15kΩ
1
LEFT AUDIO
INPUT
INL
19
17
OUTL+
10kΩ
4.5V TO 5.5V
SUPPLY
10kΩ
12
V
DD
PV
DD
0.1μF
2,18
OUTL-
0/MAX971
2
BIAS
BIAS
C
BIAS
1μF
PGND
6, 11, 15, 20
9
OUTR-
14 SHDN
4
5
MUTE
10kΩ
10kΩ
7
OUTR+
C
0.1μF
IN
R
IN
15kΩ
INR
RIGHT AUDIO
INPUT
MAX9710
R
F
15kΩ
PIN NUMBERS SHOWN ARE FOR THE 20 TQFN-EP PACKAGE.
10 ______________________________________________________________________________________
3W Mono/Stereo BTL Audio Power Amplifiers
with Shutdown
0/MAX971
Functional Diagrams (continued)
R
F
15kΩ
C
0.1μF
IN
R
IN
15kΩ
2
8
LEFT AUDIO
INPUT
IN
OUT+
OUT-
4
4.5V TO 5.5V
SUPPLY
10kΩ
10kΩ
V
DD
0.1μF
5,11 PV
DD
12
10 SHDN
9
7
MUTE
BIAS
MAX9711
BIAS
C
1μF
BIAS
GND
PGND
6
1, 3
Pin Configurations (continued)
TOP VIEW
OUT- PV
SHDN
10
DD
12
11
PGND
IN
1
2
3
9
8
7
MUTE
V
DD
MAX9711
PGND
BIAS
4
5
6
OUT+ PV
GND
DD
QFN
______________________________________________________________________________________ 11
3W Mono/Stereo BTL Audio Power Amplifiers
with Shutdown
System Diagram
V
(5V)
DD
0.1μF
15kΩ
0.1μF
15kΩ
INR
OUTR+
OUTR-
V
DD
PV
DD
0.1μF
MUTE
BIAS
AUX_IN
1μF
MAX9710
1μF
OUT
SHDN
INL
MAX4060
OUTL-
OUTL+
0.1μF
15kΩ
0/MAX971
CODEC
BIAS
15kΩ
2.2kΩ
V
CC
0.1μF
0.1μF
IN+
IN-
100kΩ
V
/2
IN-
Q
Q
DD
MAX961
IN+
100kΩ
0.1μF
SHDNL
SHDNR
1μF
1μF
OUTL
OUTR
MAX4411
INL
INR
V
CC
(3.3V)
PV
SS
SV
SS
V
CC
C1P
CIN
1μF
1μF
1μF
Chip Information
Package Information
For the latest package outline information and land patterns, go
MAX9710 TRANSISTOR COUNT: 1172
MAX9711 TRANSISTOR COUNT: 780
PROCESS: BiCMOS
to www.maxim-ic.com/packages.
PACKAGE TYPE PACKAGE CODE DOCUMENT NO.
20 TQFN-EP
12 TQFN-EP
T2055-4
T1244-4
21-0140
21-0139
12 ______________________________________________________________________________________
3W Mono/Stereo BTL Audio Power Amplifiers
with Shutdown
0/MAX971
Revision History
REVISION
NUMBER
REVISION
DATE
PAGES
CHANGED
DESCRIPTION
0
1
4/03
6/08
Initial release
—
Removed TSSOP package
1, 2, 6, 9, 10
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 13
© 2008 Maxim Integrated Products
is a registered trademark of Maxim Integrated Products, Inc.
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