19-2387; Rev 1; 10/02
1.4W and 1W, Ultra-Small, Audio Power
Amplifiers with Shutdown
General Description
The MAX4364/MAX4365 are bridged audio power
amplifiers intended for portable audio devices with
internal speakers. The MAX4364 is capable of deliver-
ing 1.4W from a single 5V supply and 500mW from a
single 3V supply into an 8Ω load. The MAX4365 is
capable of delivering 1W from a single 5V supply and
450mW from a single 3V supply into an 8Ω load. The
MAX4364/MAX4365 feature 0.04% THD + N at 1kHz,
68dB PSRR at 217Hz and only 10nA of supply current
in shutdown mode.
The MAX4364/MAX4365 bridged outputs eliminate the
need for output-coupling capacitors, minimizing exter-
nal component count. The MAX4364/MAX4365 also
include internal DC bias generation, clickless operation,
short-circuit and thermal-overload protection. Both
devices are unity-gain stable, with the gain set by two
external resistors.
The MAX4364 is available in a small 8-pin SO package.
The MAX4365 is available in tiny 8-pin thin QFN
(3mm
✕
3mm
✕
0.8mm) and µMAX packages.
o
1.4W into 8Ω Load (MAX4364)
o
1W into 8Ω Load (MAX4365)
o
0.04% THD + N at 1kHz
o
68dB PSRR at 217Hz
o
2.7V to 5.5V Single-Supply Operation
o
5mA Supply Current
o
Low-Power, 10nA Shutdown Mode
o
Pin Compatible with the LM4861/LM4862/LM4864
(MAX4364)
o
Clickless Power-Up and Shutdown
o
Thermal-Overload and Short-Circuit Protection
o
Available in Thin QFN, µMAX, and SO Packages
Features
MAX4364/MAX4365
Ordering Information
PART
MAX4364ESA
MAX4365EUA
MAX4365ETA
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
8 SO
8 µMAX
8 Thin QFN-EP*
TOP
MARK
—
—
ACD
Applications
Cellular Phones
PDAs
Two-Way Radios
General-Purpose Audio
*EP
= Exposed paddle.
Pin Configurations appear at end of data sheet.
Typical Application Circuit/Functional Diagram
V
CC
6
V
CC
50kΩ
2 BIAS
OUT- 8
C
BIAS
50kΩ
CLICKLESS/POPLESS
SHUTDOWN CONTROL
SHDN 1
3 IN+
C
IN
AUDIO
INPUT
R
IN
10kΩ
10kΩ
OUT+ 5
4 IN-
MAX4364
GND
R
F
7
________________________________________________________________
Maxim Integrated Products
1
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.
1.4W and 1W, Ultra-Small, Audio Power
Amplifiers with Shutdown
MAX4364/MAX4365
ABSOLUTE MAXIMUM RATINGS
V
CC
, OUT_ to GND...................................................-0.3V to +6V
IN+, IN-, BIAS, SHDN to GND....................-0.3V to (V
CC
+ 0.3V)
Output Short Circuit (OUT+ to OUT-) (Note 1)...........Continuous
Continuous Power Dissipation (T
A
= +70°C)
8-Pin µMAX (derate 4.1mW/°C above +70°C) ..............330mW
8-Pin Thin QFN (derate 24.4mW/°C above +70°C) ....1951mW
8-Pin SO (derate 5.88mW/°C above +70°C).................471mW
Note 1:
Continuous power dissipation must also be observed.
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.
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
ELECTRICAL CHARACTERISTICS—5V
(V
CC
= 5V, R
L
=
∞,
C
BIAS
= 1µF to GND, SHDN = GND, T
A
= +25°C, unless otherwise noted.) (Note 2)
PARAMETER
Supply Voltage Range
SYMBOL
V
CC
CONDITIONS
Inferred from PSRR test
MAX4364
Supply Current
I
CC
(Note 3)
MAX4364, T
A
= T
MIN
to T
MAX
MAX4365
MAX4365, T
A
= T
MIN
to T
MAX
Shutdown Supply Current
I
SHDN
SHDN = V
CC
V
IH
SHDN Threshold
V
IL
Common-Mode Bias Voltage
Output Offset Voltage
Power-Supply Rejection Ratio
V
BIAS
V
OS
PSRR
(Note 4)
IN- = OUT+, IN+ = BIAS (Note 5)
V
CC
= 2.7V to 5.5V
V
RIPPLE
= 200mV
P-P
,
R
L
= 8Ω
R
L
= 8Ω, THD + N = 1%,
f
IN
= 1kHz (Note 6)
DC
217Hz
1kHz
MAX4364
MAX4365
MAX4364,
P
OUT
= 1W
MAX4365,
P
OUT
= 750mW
1200
800
55
V
CC
/2 -
5%
V
CC
/2
±1
75
68
58
1400
mW
1000
0.04
%
0.1
12
600
160
15
t
PU
t
SHDN
t
ENABLE
50
10
50
µV
RMS
mA
o
o
MIN
2.7
TYP
7
5
0.01
MAX
5.5
13
17
8
11
4
UNITS
V
mA
µA
V
CC
x
0.7
V
V
CC
x
0.3
V
CC
/2
+ 5%
±10
V
mV
dB
Output Power
P
OUT
Total Harmonic Distortion Plus
Noise
Noise
Short-Circuit Current
Thermal Shutdown Threshold
Thermal Shutdown Hysteresis
Power-Up Time
Shutdown Time
Enable Time from Shutdown
THD + N
A
V
= -2V/V, R
L
= 8Ω,
f
IN
= 1kHz (Notes 7, 8)
f
IN
= 10kHz, BW = 22Hz to 22kHz
I
SC
OUT+ to OUT- (Note 9)
C
C
ms
µs
ms
2
_______________________________________________________________________________________
1.4W and 1W, Ultra-Small, Audio Power
Amplifiers with Shutdown
ELECTRICAL CHARACTERISTICS—3V
(V
CC
= 3V, R
L
=
∞,
C
BIAS
= 1µF to GND, SHDN = GND, T
A
= +25°C, unless otherwise noted.) (Note 2)
PARAMETER
Supply Current
Shutdown Supply Current
Output Power
SYMBOL
I
CC
I
SHDN
P
OUT
(Note 3)
SHDN = V
CC
R
L
= 8Ω, THD + N =
1%, f
IN
= 1kHz
(Note 6)
MAX4364
MAX4365
MAX4364,
P
OUT
= 400mW
400
350
CONDITIONS
MAX4364
MAX4365
MIN
TYP
6
4.5
10
500
mW
450
0.05
%
0.08
MAX
UNITS
mA
nA
MAX4364/MAX4365
Total Harmonic Distortion Plus
Noise
THD + N
A
V
= -2V/V, R
L
= 8Ω,
f
IN
= 1kHz (Notes 7, 8) MAX4365,
P
OUT
= 400mW
Note 2:
All specifications are 100% tested at T
A
= +25°C.
Note 3:
Quiescent power-supply current is specified and tested with no load on the outputs. Quiescent power-supply current
depends on the offset voltage when a practical load is connected to the amplifier.
Note 4:
Common-mode bias voltage is the voltage on BIAS and is nominally V
CC
/2.
Note 5:
Maximum differential-output offset voltage is tested in a unity-gain configuration. V
OS
= V
OUT+
- V
OUT-
.
Note 6:
Output power is specified by a combination of a functional output-current test, and characterization analysis.
Note 7:
Guaranteed by design, not production tested.
Note 8:
Measurement bandwidth for THD + N is 22Hz to 22kHz.
Note 9:
Extended short-circuit conditions result in a pulsed output.
Typical Operating Characteristics
(V
CC
= 5V, THD + N measurement bandwidth = 22Hz to 22kHz, T
A
= +25°C, unless otherwise noted.)
MAX4364
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. FREQUENCY
MAX4364 toc01
MAX4364
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. FREQUENCY
MAX4364 toc02
MAX4364
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. FREQUENCY
V
CC
= 5V
A
V
= 20V/V
R
L
= 8Ω
THD + N (%)
1
0.25W
MAX4364 toc03
10
V
CC
= 5V
A
V
= 2V/V
R
L
= 8Ω
THD + N (%)
1
10
V
CC
= 5V
A
V
= 4V/V
R
L
= 8Ω
THD + N (%)
1
10
0.1
0.25W
0.5W
0.1
0.25W
0.5W
1W
0.1
1W
0.5W
0.01
0
100
1W
1k
10k
FREQUENCY (Hz)
0.01
0
100
1k
10k
FREQUENCY (Hz)
0.01
0
100
1k
10k
FREQUENCY (Hz)
_______________________________________________________________________________________
3
1.4W and 1W, Ultra-Small, Audio Power
Amplifiers with Shutdown
MAX4364/MAX4365
Typical Operating Characteristics (continued)
(V
CC
= 5V, THD + N measurement bandwidth = 22Hz to 22kHz, T
A
= +25°C, unless otherwise noted.)
MAX4364
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. FREQUENCY
MAX4364 toc04
MAX4364
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. FREQUENCY
MAX4364 toc05
MAX4364
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. FREQUENCY
V
CC
= 3V
A
V
= 20V/V
R
L
= 8Ω
THD + N (%)
1
0.25W
MAX4364 toc06
MAX4364 toc12
MAX4364 toc09
10
V
CC
= 3V
A
V
= 2V/V
R
L
= 8Ω
THD + N (%)
1
0.4W
0.1
0.25W
10
V
CC
= 3V
A
V
= 4V/V
R
L
= 8Ω
THD + N (%)
1
10
0.1
0.25W
0.1
0.4W
0.4W
0.01
0
100
1k
10k
FREQUENCY (Hz)
0.01
0
100
1k
10k
FREQUENCY (Hz)
0.01
0
100
1k
10k
FREQUENCY (Hz)
MAX4364
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. OUTPUT POWER
MAX4364 toc07
MAX4364
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. OUTPUT POWER
MAX4364 toc08
MAX4364
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. OUTPUT POWER
100
V
CC
= 3V
A
V
= 2V/V
R
L
= 8Ω
100
V
CC
= 5V
A
V
= 2V/V
R
L
= 8Ω
100
V
CC
= 5V
A
V
= 4V/V
R
L
= 8Ω
20kHz
20Hz
0.1
1kHz
10
THD + N (%)
10
THD + N (%)
10
THD + N (%)
1
20kHz
0.1
1kHz
20Hz
1
1
20kHz
0.1
1kHz
0.01
0.01
0.01
20Hz
0.001
0 40
200
520
1000
1650
2450
OUTPUT POWER (mW)
0.001
0 40
200
520
1000
1650
2450
OUTPUT POWER (mW)
0.001
0 20
190
525
1000
1700
2500
OUTPUT POWER (mW)
MAX4364
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. OUTPUT POWER
MAX4364 toc10
MAX4364
OUTPUT POWER vs. SUPPLY VOLTAGE
MAX4364 toc11
MAX4364
OUTPUT POWER vs. LOAD RESISTANCE
3000
V
CC
= 5V
f
IN
= 1kHz
100
V
CC
= 3V
A
V
= 4V/V
R
L
= 8Ω
2500
R
L
= 8Ω
f
IN
= 1kHz
10% THD + N
10
THD + N (%)
2000
OUTPUT POWER (mW)
2400
OUTPUT POWER (mW)
1
20kHz
1500
1800
10% THD + N
0.1
1kHz
1000
1200
0.01
20Hz
500
1% THD + N
600
1% THD + N
0.001
0 40
200
520
1000
1650
2440
OUTPUT POWER (mW)
0
2.7
3.4
4.1
4.8
5.5
SUPPLY VOLTAGE (V)
0
0
10
20
30
40
50
LOAD RESISTANCE (Ω)
4
_______________________________________________________________________________________
1.4W and 1W, Ultra-Small, Audio Power
Amplifiers with Shutdown
Typical Operating Characteristics (continued)
(V
CC
= 5V, THD + N measurement bandwidth = 22Hz to 22kHz, T
A
= +25°C, unless otherwise noted.)
MAX4364
OUTPUT POWER vs. LOAD RESISTANCE
MAX4364 toc13
MAX4364/MAX4365
MAX4364
POWER DISSIPATION vs. OUTPUT POWER
MAX4364 toc14
MAX4364
POWER DISSIPATION vs. OUTPUT POWER
270
POWER DISSIPATION (mW)
240
210
180
150
120
90
60
30
0
V
CC
= 3V
f
IN
= 1kHz
R
L
= 8Ω
0
100
200
300
400
500
MAX4364 toc15
1200
1000
OUTPUT POWER (mW)
800
600
400
200
1% THD + N
0
0
10
20
30
10% THD + N
V
CC
= 3V
f
IN
= 1kHz
700
630
POWER DISSIPATION (mW)
560
490
420
350
280
210
140
70
0
V
CC
= 5V
f
IN
= 1kHz
R
L
= 8Ω
0
300
600
900
1200
300
40
50
1500
LOAD RESISTANCE (Ω)
OUTPUT POWER (mW)
OUTPUT POWER (mW)
MAX4364
SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX4364 toc16
MAX4364
SUPPLY CURRENT vs. TEMPERATURE
V
CC
= 5V
9
SUPPLY CURRENT (mA)
MAX4364 toc17
MAX4364
SHUTDOWN SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX4364 toc18
9.0
8.5
SUPPLY CURRENT (mA)
8.0
7.5
7.0
6.5
6.0
2.7
3.4
4.1
4.8
10
12
10
SUPPLY CURRENT (nA)
8
6
4
2
0
8
7
6
5
5.5
-40
-15
10
35
60
85
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
2.7
3.4
4.1
4.8
5.5
SUPPLY VOLTAGE (V)
MAX4364
SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE
V
CC
= 5V
80
SUPPLY CURRENT (nA)
MAX4364 toc19
MAX4365
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. FREQUENCY
MAX4364 toc20
MAX4365
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. FREQUENCY
V
CC
= 5V
A
V
= 4V/V
R
L
= 8Ω
THD + N (%)
1
0.25W
0.5W
0.1
0.75W
MAX4364 toc21
100
10
V
CC
= 5V
A
V
= 2V/V
R
L
= 8Ω
THD + N (%)
1
0.25W
0.5W
0.1
0.75W
10
60
40
20
0
-40
-15
10
35
60
85
TEMPERATURE (°C)
0.01
0
100
1k
10k
FREQUENCY (Hz)
0.01
0
100
1k
10k
FREQUENCY (Hz)
_______________________________________________________________________________________
5