General Description
The MAX9718/MAX9719 differential input audio power
amplifiers are ideal for portable audio devices with
internal speakers. The differential input structure
improves noise rejection and provides common-mode
rejection. A bridge-tied load (BTL) architecture mini-
mizes external component count, while providing high-
quality, power audio amplification. The MAX9718 is a
single-channel amplifier while the MAX9719 is a dual-
channel amplifier for stereo systems. Both devices
deliver 1.4W continuous average power per channel to
a 4
load with less than 1% THD+N while operating
from a single +5V supply. The devices are available as
adjustable gain amplifiers or with internally fixed gains
of 0dB, 3dB, and 6dB to reduce component count.
A shutdown input disables the bias generator and
amplifiers and reduces quiescent current consumption
to less than 100nA. The MAX9718 shutdown input can
be set as active high or active low. These devices fea-
ture Maxim's comprehensive click-and-pop suppres-
sion circuitry that reduces audible clicks and pops
during startup and shutdown.
The MAX9718 is pin compatible with the LM4895,
and is available in 9-bump UCSPTM, 10-pin TDFN, and
10-pin MAX packages. The MAX9719 is available in
16-pin TQFN, 16-pin TSSOP, and 16-bump UCSP pack-
ages. Both devices operate over the -40C to +85C
extended temperature range.
Applications
Mobile Phones
PDAs
Portable Devices
Features
o 2.7V to 5.5V Single-Supply Operation
o Very High -93dB PSRR at 217Hz
o 1.4W into 4 at 1% THD+N (per Channel)
o Differential Input
o Internal Fixed Gain to Reduce Component Count
o Adjustable Gain Option (MAX9718A/MAX9719A)
o 100nA Low-Power Shutdown Mode
o No Audible Clicks or Pops at Power-Up/Down
o Improved Performance Pin-Compatible Upgrade
to LM4895 (MAX9718D)
MAX9718/MAX9719
Low-Cost, Mono/Stereo,
1.4W Differential Audio Power Amplifiers
________________________________________________________________ Maxim Integrated Products
1
Ordering Information
MAX9719
SINGLE SUPPLY
2.7V TO 5.5V
SHDN
INL+
INL-
INR+
INR-
MAX9718
SINGLE SUPPLY
2.7V TO 5.5V
SHDM
SHDN
IN+
OUT+
OUT-
OUTR-
OUTR+
OUTL-
OUTL+
IN-
Simplified Block Diagram
19-3050; Rev 0; 10/03
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 continued at end of data sheet.
Pin Configurations appear at end of data sheet.
UCSP is a trademark of Maxim Integrated Products, Inc.
PART
TEMP
RANGE
PIN-
PACKAGE
GAIN
(dB)
MAX9718AEBL-T* -40C to +85C 3 x 3 UCSP
Adj
MAX9718AETB*
-40C to +85C 10 TDFN-EP**
Adj
MAX9718AEUB
-40C to +85C 10 MAX-EP**
Adj
*Future product--contact factory for availability.
**EP = Exposed paddle.
MAX9718/MAX9719
Low-Cost, Mono/Stereo,
1.4W Differential Audio Power Amplifiers
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS--5V Supply
(V
CC
= 5V, GND = 0, SHDN/SHDN = V
CC
(MAX9718/MAX9719), SHDM = GND (MAX9718), R
IN
= R
F
= 10k
(MAX971_A),
T
A
= +25C. C
BIAS
= 0.1F, no load. Typical values are at T
A
= +25C, unless otherwise noted.) (Note 1)
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.
Supply Voltage (V
CC
to GND) ..................................-0.3V to +6V
Any Other Pin to GND ...............................-0.3V to (V
CC
+ 0.3V)
IN_, BIAS, SHDM, SHDN, SHDN Continuous Current ........20mA
OUT_ Short-Circuit Duration to GND or V
CC
.............Continuous
Continuous Power Dissipation (T
A
= +70C)
9-Bump UCSP (derate 5.2mW/C above +70C)..........412mW
10-Pin TDFN (derate 24.4mW/C above +70C) ........1951mW
10-Pin MAX (derate 10.3mW/C above +70C) ..........825mW
16-Bump UCSP (derate 8.2mW/C above +70C) .......659mW
16-Pin TQFN (derate 16.9mW/C above +70C) ........1349mW
16-Pin TSSOP (derate 21.3mW/C above +70C) ......1702mW
Operating Temperature Range ...........................-40C to +85C
Junction Temperature .....................................................+150C
Storage Temperature Range .............................-65C to +150C
Bump Temperature (soldering) Reflow............................+235C
Lead Temperature (soldering, 10s) .................................+300C
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Supply Voltage
V
CC
2.7
5.5
V
Supply Current
I
CC
V
IN-
= V
IN+
= V
BIAS
, T
A
= -40C to +85C,
per amplifier (Note 2)
5.0
7.5
mA
Shutdown Supply Current
I
SHDN
SHDN = SHDM = SHDN = GND, per amplifier
0.1
1
A
V
IH
0.7 x V
CC
SHDN, SHDN, SHDM
Threshold
V
IL
0.3 x V
CC
V
Common-Mode Bias Voltage
V
BIAS
(Note 3)
V
CC
/2
- 5%
V
CC
/2
V
CC
/2 +
5%
V
A
V
= 0dB, MAX971_A,
MAX971_B
1
10
A
V
= 3dB, MAX971_C
1
15
Output Offset Voltage
V
OS
V
IN-
= V
IN+
= V
BIAS
A
V
= 6dB, MAX971_D
1
20
mV
A
V
= 0dB, MAX971_B
0.5
V
CC
- 0.5
A
V
= 3dB, MAX971_C
0.5
V
CC
- 0.6
Inferred from
CMRR test
A
V
= 6dB, MAX971_D
0.5
V
CC
- 0.8
Common-Mode Input Voltage
V
IC
External gain, MAX971_A
0.5
V
CC
- 1.2
V
Input Impedance
R
IN
MAX971_B, MAX971_C, MAX971_D
10
15
20
k
-50
-60
Common-Mode Rejection Ratio
CMRR
f
n
= 1kHz
-60
dB
f = 217Hz
-93
Power-Supply Rejection Ratio
PSRR
V
IN-
= V
IN+
= V
BIAS
,
V
RIPPLE
= 200m V
P-P
,
R
L
= 8
, C
BIAS
= 1F
f = 1kHz
-90
dB
R
L
= 8
0.8
1.1
Output Power
P
OUT
THD+N = 1%,
f
IN
= 1kHz (Note 4)
R
L
= 4
1.4
W
Total Harmonic Distortion Plus
Noise
THD+N
R
L
= 8
, f
IN
= 1kHz, P
OUT
= 0.75W,
V
CC
= 5V, A
V
= 6dB (Note 5)
0.002
%
MAX9718/MAX9719
Low-Cost, Mono/Stereo,
1.4W Differential Audio Power Amplifiers
_______________________________________________________________________________________
3
ELECTRICAL CHARACTERISTICS--5V Supply (continued)
(V
CC
= 5V, GND = 0, SHDN/SHDN = V
CC
(MAX9718/MAX9719), SHDM = GND (MAX9718), R
IN
= R
F
= 10k
(MAX971_A),
T
A
= +25C. C
BIAS
= 0.1F, no load. Typical values are at T
A
= +25C, unless otherwise noted.) (Note 1)
ELECTRICAL CHARACTERISTICS--3V Supply
(V
CC
= 3V, GND = 0, SHDN/SHDN = V
CC
(MAX9718/MAX9719), SHDM = GND (MAX9718), R
IN
= R
F
= 10k
(MAX971_A),
T
A
= +25C. C
BIAS
= 0.1F, no load. Typical values are at T
A
= +25C, unless otherwise noted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Gain Accuracy
MAX971_B/MAX971_C/MAX971_D
1
%
Channel-to-Channel Gain
Matching
MAX9719B/MAX9719C/MAX9719D
1
%
Signal-to-Noise Ratio
SNR
P
OUT
= 1W, R
L
= 8
-104
dB
Thermal-Shutdown Threshold
+160
C
Thermal-Shutdown Hysteresis
15
C
Maximum Capacitive Drive
C
LOAD
Bridge-tied capacitance
500
pF
Power-Up/Enable from
Shutdown Time
t
PU
10
ms
Shutdown Time
t
SHDN
3.5
s
Turn-Off Transient
V
POP
(Note 6)
50
mV
Crosstalk
MAX9719, f
IN
= 1kHz
-85
dB
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Supply Current
I
CC
V
IN-
= V
IN+
= V
BIAS
, T
A
= -40C to +85C,
per amplifier (Note 2)
3.8
6.0
mA
Shutdown Supply Current
I
SHDN
SHDN = SHDM = SHDN = GND, per amplifier
0.1
1
A
V
IH
0.7 x V
CC
SHDN, SHDN, SHDM
Threshold
V
IL
0.3 x V
CC
V
Common-Mode Bias Voltage
V
BIAS
(Note 3)
V
CC
/2
- 5%
V
CC
/2
V
CC
/2
+ 5%
V
A
V
= 0dB, MAX971_A/
MAX971_B
1
10
A
V
= 3dB, MAX971_C
1
15
Output Offset Voltage
V
OS
V
IN-
= V
IN+
= V
BIAS
A
V
= 6dB, MAX971_D
1
20
mV
A
V
= 0dB, MAX971_B
0.5
V
CC
- 0.7
A
V
= 3dB, MAX971_C
0.5
V
CC
- 0.8
Inferred from
CMRR test
A
V
= 6dB, MAX971_D
0.5
V
CC
- 1.0
Common-Mode Input Voltage
V
IC
External gain, MAX971_A
0.5
V
CC
- 1.2
V
Input Impedance
R
IN
MAX971_B/MAX971_C/MAX971_D
10
15
20
k
-50
-60
Common-Mode Rejection Ratio
CMRR
f
N
= 1kHz
-70
dB
f = 217Hz
-93
Power-Supply Rejection Ratio
PSRR
V
IN-
= V
IN+
= V
BIAS
,
V
RIPPLE
= 200m V
P-P
,
R
L
= 8
,
C
BIAS
= 1F
f = 1kHz
-90
dB
TOTAL HARMONIC DISTORTION + NOISE
vs. FREQUENCY
MAX9718 toc01
FREQUENCY (Hz)
THD+N (%)
100
1k
10k
0.001
0.01
0.1
1
10
0.0001
10
100k
V
CC
= 5V
R
L
= 4
A
V
= 2
OUTPUT POWER = 1W
OUTPUT POWER = 50mW
TOTAL HARMONIC DISTORTION + NOISE
vs. FREQUENCY
MAX9718 toc02
FREQUENCY (Hz)
THD+N (%)
100
1k
10k
0.001
0.01
0.1
1
10
0.0001
10
100k
V
CC
= 5V
R
L
= 4
A
V
= 4
OUTPUT POWER = 1W
OUTPUT POWER = 200mW
TOTAL HARMONIC DISTORTION + NOISE
vs. FREQUENCY
MAX9718 toc03
FREQUENCY (Hz)
THD+N (%)
100
1k
10k
0.001
0.01
0.1
1
10
0.0001
10
100k
V
CC
= 5V
R
L
= 8
A
V
= 2
OUTPUT POWER = 250mW
OUTPUT POWER = 750mW
Typical Operating Characteristics
(V
CC
= 5V, C
BIAS
= 0.1F, THD+N measurement bandwidth = 22Hz to 22kHz, T
A
= +25C, unless otherwise noted.)
Note 1: All specifications are 100% tested at T
A
= +25C. Specifications over temperature (T
A
= T
MIN
to T
MAX
) are guaranteed by
design, not production tested.
Note 2: Quiescent power-supply current is specified and tested with no load. Quiescent power-supply current depends on the offset
voltage when a practical load is connected to the amplifier. Guaranteed by design.
Note 3: Common-mode bias voltage is the voltage on BIAS and is nominally V
CC
/2.
Note 4: Output power is specified by a combination of a functional output current test and characterization analysis.
Note 5: Measurement bandwidth for THD+N is 22Hz to 22kHz.
Note 6: Peak voltage measured at power-on, power-off, into or out of SHDN. Bandwidth defined by A-weighted filters, inputs at AC
GND. V
CC
rise and fall times greater than or equal to 1ms.
MAX9718/MAX9719
Low-Cost, Mono/Stereo,
1.4W Differential Audio Power Amplifiers
4
_______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS--3V Supply (continued)
(V
CC
= 3V, GND = 0, SHDN/SHDN = V
CC
(MAX9718/MAX9719), SHDM = GND (MAX9718), R
IN
= R
F
= 10k
(MAX971_A),
T
A
= +25C. C
BIAS
= 0.1F, no load. Typical values are at T
A
= +25C, unless otherwise noted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Output Power
P
OUT
R
L
= 8
, THD+N = 1%, f
IN
= 1kHz (Note 4)
475
mW
Total Harmonic Distortion Plus
Noise
THD+N
R
L
= 8
, f
IN
= 1kHz, P
OUT
= 0.25W,
A
V
= 6dB
0.003
%
Thermal-Shutdown Threshold
+160
C
Thermal-Shutdown Hysteresis
15
C
Maximum Capacitive Drive
C
LOAD
Bridge-tied capacitance
500
pF
Power-Up/Enable from
Shutdown Time
t
PU
10
ms
Shutdown Time
t
SHDN
3
s
Turn-Off Transient
V
POP
(Note 6)
40
mV
Crosstalk
MAX9719, f
N
= 1kHz
-85
dB
MAX9718/MAX9719
Low-Cost, Mono/Stereo,
1.4W Differential Audio Power Amplifiers
_______________________________________________________________________________________
5
TOTAL HARMONIC DISTORTION + NOISE
vs. FREQUENCY
MAX9718 toc04
FREQUENCY (Hz)
THD+N (%)
100
1k
10k
0.001
0.01
0.1
1
10
0.0001
10
100k
V
CC
= 5V
R
L
= 8
A
V
= 4
OUTPUT POWER = 200mW
OUTPUT POWER = 800mW
TOTAL HARMONIC DISTORTION + NOISE
vs. FREQUENCY
MAX9718 toc05
FREQUENCY (Hz)
THD+N (%)
100
1k
10k
0.001
0.01
0.1
1
10
0.0001
10
100k
V
CC
= 3V
R
L
= 4
A
V
= 2
OUTPUT POWER = 250mW
OUTPUT POWER = 50mW
TOTAL HARMONIC DISTORTION + NOISE
vs. FREQUENCY
MAX9718 toc06
FREQUENCY (Hz)
THD+N (%)
100
1k
10k
0.001
0.01
0.1
1
10
0.0001
10
100k
V
CC
= 3V
R
L
= 4
A
V
= 4
OUTPUT POWER = 70mW
OUTPUT POWER = 175mW
TOTAL HARMONIC DISTORTION + NOISE
vs. FREQUENCY
MAX9718 toc07
FREQUENCY (Hz)
THD+N (%)
100
1k
10k
0.001
0.01
0.1
1
10
0.0001
10
100k
V
CC
= 3V
R
L
= 8
A
V
= 2
OUTPUT POWER = 250mW
OUTPUT POWER = 100mW
TOTAL HARMONIC DISTORTION + NOISE
vs. FREQUENCY
MAX9718 toc08
FREQUENCY (Hz)
THD+N (%)
100
1k
10k
0.001
0.01
0.1
1
10
0.0001
10
100k
V
CC
= 3V
R
L
= 8
A
V
= 4
OUTPUT POWER = 200mW
OUTPUT POWER = 50mW
TOTAL HARMONIC DISTORTION + NOISE
vs. OUTPUT POWER
MAX9718 toc09
OUTPUT POWER (W)
THD+N (%)
0.2 0.4 0.6 0.8
1.2 1.4
1.0
1.8
0.01
0.1
1
10
100
0.001
0
2.0
f
IN
= 1kHz
f
IN
= 100Hz
f
IN
= 10kHz
1.6
V
CC
= 5V
R
L
= 4
A
V
= 2
TOTAL HARMONIC DISTORTION + NOISE
vs. OUTPUT POWER
MAX9718 toc10
OUTPUT POWER (W)
THD+N (%)
0.5
1.5
1.0
0.01
0.1
1
10
100
0.001
0
2.0
f
IN
= 1kHz
f
IN
= 100Hz
f
IN
= 10kHz
V
CC
= 5V
R
L
= 4
A
V
= 4
TOTAL HARMONIC DISTORTION + NOISE
vs. OUTPUT POWER
MAX9718 toc11
OUTPUT POWER (W)
THD+N (%)
0.2
0.6
0.8
1.0
1.2
0.4
0.01
0.1
1
10
100
0.001
0
1.4
f
IN
= 1kHz
f
IN
= 100Hz
f
IN
= 10kHz
V
CC
= 5V
R
L
= 8
A
V
= 2
TOTAL HARMONIC DISTORTION + NOISE
vs. OUTPUT POWER
MAX9718 toc12
OUTPUT POWER (W)
THD+N (%)
0.2
0.6
0.8
1.0
1.2
0.4
0.01
0.1
1
10
100
0.001
0
1.4
f
IN
= 100Hz
f
IN
= 1kHz
f
IN
= 10kHz
V
CC
= 5V
R
L
= 8
A
V
= 4
Typical Operating Characteristics (continued)
(V
CC
= 5V, C
BIAS
= 0.1F, THD+N measurement bandwidth = 22Hz to 22kHz, T
A
= +25C, unless otherwise noted.)
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