19-4666; Rev 0; 7/09
KIT
ATION
EVALU
E
BL
AVAILA
DirectDrive Headphone Amplifier
with External Gain
General Description
Features
♦
Clickless/Popless Operation
♦
High RF Noise Rejection
♦
Windows Vista Premium Mobile Compliant
♦
2.7V to 5.5V Single-Supply Operation
♦
95mW Output Power (32Ω, V
DD
= 5V)
♦
Low-Current Shutdown Mode, < 1µA
♦
Low 3mA (V
DD
= 3.3V) Quiescent Current
♦
Space-Saving, 3mm x 3mm, 10-Pin TDFN Package
MAX9820
The MAX9820 Windows Vista
®
-compliant stereo head-
phone amplifier is designed for portable equipment
where board space is at a premium. It features Maxim’s
DirectDrive
®
architecture to produce a ground-refer-
enced output from a single supply, eliminating the large
output-coupling capacitors required by conventional
single-supply headphone amplifiers.
The MAX9820 features an undervoltage lockout that
prevents over discharging of the battery during
brownout conditions, click-and-pop suppression that
eliminates audible transients on startup, a low-power
shutdown mode, and thermal-overload and short-circuit
protection. Additionally, the MAX9820 suppresses RF
radiation received by input and supply traces acting as
antennas and prevents the amplifier from demodulating
the coupled noise.
The MAX9820 is available in a 10-pin TDFN package
(3mm x 3mm x 0.8mm) and specified over the -40°C to
+85°C extended temperature range.
Ordering Information
PART
TEMP RANGE
PIN-
PACKAGE
10 TDFN-EP*
TOP MARK
AUU
Applications
Cell Phones
MP3 Players
Notebook PCs
PDAs
MAX9820ETB+ -40°C to +85°C
+Denotes
a lead(Pb)-free/RoHS-compliant package.
*EP
= Exposed pad.
Pin Configuration
TOP VIEW
Simplified Block Diagram
C1P
C1N
V
SS
OUTL
OUTR
1
2
3
4
5
*EP
10
9
GND
SHDN
V
DD
INL
INR
MAX9820
LEFT
AUDIO
INPUT
DirectDrive OUTPUTS
ELIMINATE DC-BLOCKING
CAPACITORS
MAX9820
8
7
6
SHDN
TDFN
*EXPOSED PAD.
RIGHT
AUDIO
INPUT
Windows Vista is a registered trademark of Microsoft Corp.
DirectDrive is a registered trademark of Maxim Integrated Products, Inc.
________________________________________________________________
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.
DirectDrive Headphone Amplifier
with External Gain
MAX9820
ABSOLUTE MAXIMUM RATINGS
V
DD
to GND ..............................................................-0.3V to +6V
C1P to GND................................................-0.3V to (V
DD
+ 0.3V)
C1N to GND ................................................(V
SS
- 0.3V) to +0.3V
V
SS
to GND...............................................................-6V to +0.3V
OUTR, OUTL to GND.............................................................±3V
SHDN
to GND...........................................................-0.3V to +6V
INR, INL to GND .........................................-0.3V to (V
DD
+ 0.3V)
OUTR, OUTL Short Circuit to GND, V
DD
....................Continuous
Short Circuit Between OUTL and OUTR ....................Continuous
Continuous Input Current (Into All Other Pins) .................±20mA
Continuous Power Dissipation (T
A
= +70°C)
10-Pin TDFN Single-Layer PCB (derate 18.5mW/°C
above +70°C)........................................................1481.5mW
Junction-to-Case Thermal Resistance (θ
JC
) (Note 1)
10-Pin TDFN ................................................................8.5°C/W
Junction-to-Ambient Thermal Resistance (θ
JA
) (Note 1)
10-Pin TDFN ...............................................................41.0°C/W
Continuous Power Dissipation (T
A
= +70°C)
10-Pin TDFN Multilayer PCB (derate 24.4mW/°C
above +70°C)...........................................................1951mW
Junction-to-Case Thermal Resistance (θ
JC
) (Note 1)
10-Pin TDFN .................................................................9.0°C/W
Junction-to-Ambient Thermal Resistance (θ
JA
) (Note 1)
10-Pin TDFN ...............................................................41.0°C/W
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Junction Temperature ......................................................+150°C
Lead Temperature (soldering, 10s) .................................+300°C
Note 1:
Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-
layer board. For detailed information on package thermal considerations, refer to
www.maxim-ic.com/thermal-tutorial.
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
DD
= V
SHDN
= 5V, V
GND
= 0V, R
IN
= R
FB
= 40.2kΩ (gain = -1V/V), C1 = C2 = 1µF, C3 = 10µF, R
LOAD
=
∞,
T
A
= -40°C to +85°C,
unless otherwise noted. Typical values are at T
A
= +25°C, unless otherwise noted.) (Note 2)
PARAMETER
GENERAL
Supply Voltage Range
Undervoltage Lockout
Quiescent Current
Shutdown Current
Output Signal Attenuation in
Shutdown
Output Impedance in
Shutdown
Turn-On Time
Output Offset Voltage
t
ON
V
OS
T
A
= +25°C (Note 3)
Z
LOAD
= 32Ω + 1µH, peak
voltage, A-weighted, 32 samples
per second (Notes 3, 4)
Click-and-Pop Level
K
CP
Z
LOAD
= 10kΩ, peak voltage,
A-weighted, 32 samples per
second (Notes 3, 4)
Into shutdown
Out of
shutdown
Into shutdown
Out of
shutdown
V
DD
UVLO
I
DD
I
SHDN
V
DD
= 3.3V
V
DD
= 5V
V
SHDN
= 0V, T
A
= +25°C
V
SHDN
= 0V, V
IN
= 1V
RMS
, R
LOAD
= 10kΩ
V
SHDN
= 0V
Guaranteed by PSRR test
2.7
2.2
3.0
4.0
< 0.1
-110
0.6
0.56
±0.1
-79
-77
dBV
-62
-58
±0.5
4.6
6.0
1
5.5
V
V
mA
µA
dBV
kΩ
ms
mV
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
2
_______________________________________________________________________________________
DirectDrive Headphone Amplifier
with External Gain
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= V
SHDN
= 5V, V
GND
= 0V, R
IN
= R
FB
= 40.2kΩ (gain = -1V/V), C1 = C2 = 1µF, C3 = 10µF, R
LOAD
=
∞,
T
A
= -40°C to +85°C,
unless otherwise noted. Typical values are at T
A
= +25°C, unless otherwise noted.) (Note 2)
PARAMETER
Power-Supply Rejection Ratio
SYMBOL
PSRR
CONDITIONS
V
DD
= 2.7V to 5.5V, T
A
= +25°C (Note 3)
f = 1kHz, 200mV
P-P
(Note 3)
f = 20kHz, 200mV
P-P
(Note 3)
Z
LOAD
= 32Ω + 1µH, f = 1kHz,
THD+N = 1%
Output Power
P
OUT
Z
LOAD
= 16Ω + 1µH, f = 1kHz,
THD+N = 1%
V
DD
= 3.6V
V
DD
= 5.0V
V
DD
= 3.6V
V
DD
= 5.0V
MIN
75
TYP
90
73
55
45
95
32
75
0.014
0.005
0.001
105
9
Z
LOAD
= 32Ω + 1µH
FS = 0.300V
RMS
,
V
OUT
= 30mV
RMS
Z
LOAD
= 10kΩ
FS = 0.707V
RMS
,
V
OUT
= 70.7mV
RMS
300
73
dB
73
200
500
145
15
V
INH
V
INL
I
LEAKAGE
T
A
= +25°C
1.2
0.3
±1
800
pF
kHz
°C
°C
V
V
µA
dB
µV
%
mW
dB
MAX
UNITS
MAX9820
Total Harmonic Distortion
Plus Noise
Signal-to-Noise Ratio
Output Noise
Z
LOAD
= 16Ω + 1µH, f = 1kHz, P
OUT
= 20mW
THD+N
SNR
V
NOISE
Z
LOAD
= 32Ω + 1µH, f = 1kHz, P
OUT
= 20mW
Z
LOAD
= 10kΩ, f = 1kHz, V
OUT
= 1V
RMS
Z
LOAD
= 32Ω + 1µH, P
OUT
= 25mW, A-weighted
A-weighted (Note 3)
Crosstalk
L to R, R to L,
BW = 20Hz to 15kHz
Capacitive Load Drive
Oscillator Frequency
Thermal Shutdown
Thermal Shutdown Hysteresis
DIGITAL INPUT (SHDN)
Input Voltage High
Input Voltage Low
Input Leakage Current
C
L
f
OSC
No sustained oscillations
T
A
= +25°C
Note 2:
All specifications are 100% tested at T
A
= +25°C; temperature limits are guaranteed by design.
Note 3:
The amplifier inputs are AC-coupled to GND.
Note 4:
Mode transitions are controlled by
SHDN.
_______________________________________________________________________________________
3
DirectDrive Headphone Amplifier
with External Gain
MAX9820
Typical Operating Characteristics
(V
DD
= V
SHDN
= 5V, V
GND
= 0V, R
IN
= R
FB
= 40.2kΩ (gain = -1V/V), C1 = C2 = 1µF, C3 = 10µF, R
LOAD
=
∞.
Typical values are at T
A
= +25°C, unless otherwise noted.)
THD+N vs. OUTPUT POWER
MAX9820 toc01
THD+N vs. OUTPUT POWER
V
DD
= 5.0V
R
LOAD
= 32I
L
LOAD
= 1FH
f = 100Hz
0.1
f = 6kHz
MAX9820 toc02
10
V
DD
= 5.0V
R
LOAD
= 16I
L
LOAD
= 1FH
f = 6kHz
0.1
f = 100Hz
10
1
THD+N (%)
1
THD+N (%)
0.01
f = 1kHz
0.01
f = 1kHz
0.001
0
0.02
0.04
0.06
0.08
0.10
0.12
0.14
OUTPUT POWER (W)
0.001
0
0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16
OUTPUT POWER (W)
THD+N vs. OUTPUT POWER
MAX9820 toc03
THD+N vs. OUTPUT POWER
V
DD
= 3.6V
R
LOAD
= 32I
L
LOAD
= 1FH
MAX9820 toc04
10
V
DD
= 3.6V
R
LOAD
= 16I
L
LOAD
= 1FH
f = 100Hz
0.1
f = 6kHz
10
1
THD+N (%)
1
THD+N (%)
0.1
f = 100Hz
f = 6kHz
0.01
f = 1kHz
0.01
f = 1kHz
0.001
0
0.01
0.02
0.03
0.04
0.05
0.06
OUTPUT POWER (W)
0.001
0
0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08
OUTPUT POWER (W)
THD+N vs. FREQUENCY
MAX9820 toc05
THD+N vs. FREQUENCY
V
DD
= 5.0V
R
LOAD
= 32I
L
LOAD
= 1FH
MAX9820 toc06
10
V
DD
= 5.0V
R
LOAD
= 16I
L
LOAD
= 1FH
10
1
THD+N (%)
1
THD+N (%)
0.1
P
OUT
= 60mW
0.1
P
OUT
= 60mW
0.01
0.01
P
OUT
= 20mW
0.001
10
100
1000
FREQUENCY (Hz)
10,000
100,000
0.001
10
P
OUT
= 20mW
100
1000
FREQUENCY (Hz)
10,000
100,000
4
_______________________________________________________________________________________
DirectDrive Headphone Amplifier
with External Gain
Typical Operating Characteristics
(V
DD
= V
SHDN
= 5V, V
GND
= 0V, R
IN
= R
FB
= 40.2kΩ (gain = -1V/V), C1 = C2 = 1µF, C3 = 10µF, R
LOAD
=
∞.
Typical values are at T
A
= +25°C, unless otherwise noted.)
THD+N vs. FREQUENCY
MAX9820 toc07
MAX9820
THD+N vs. FREQUENCY
V
DD
= 3.6V
R
LOAD
= 32I
L
LOAD
= 1FH
MAX9820 toc08
10
V
DD
= 3.6V
R
LOAD
= 16I
L
LOAD
= 1FH
10
1
THD+N (%)
1
THD+N (%)
0.1
P
OUT
= 20mW
0.01
P
OUT
= 10mW
0.001
10
100
1000
FREQUENCY (Hz)
10,000
100,000
0.1
P
OUT
= 30mW
0.01
P
OUT
= 10mW
0.001
10
100
1000
FREQUENCY (Hz)
10,000
100,000
VISTA THD+N vs. FREQUENCY
MAX9820 toc09
VISTA THD+N vs. FREQUENCY
V
DD
= 5.0V
R
LOAD
= 10kI
L
LOAD
= 1µH
V
OUT
= -3dBFS
MAX9820 toc10
0
-20
-40
-60
-80
-100
FS = 1V
RMS
-120
10
100
1000
FREQUENCY (Hz)
10,000
V
DD
= 5.0V
R
LOAD
= 32I
L
LOAD
= 1FH
V
OUT
= -3dBFS
0
-20
-40
-60
FS = 707mV
RMS
-80
-100
FS = 1V
RMS
-120
THD+N (dBFS)
FS = 300mV
RMS
100,000
THD+N (dBFS)
10
100
1000
FREQUENCY (Hz)
10,000
100,000
OUTPUT POWER vs. SUPPLY VOLTAGE
MAX9820 toc11
OUTPUT POWER vs. SUPPLY VOLTAGE
R
LOAD
= 32I
L
LOAD
= 1µH
MAX9820 toc12
180
150
120
P
OUT
(mW)
THD+N = 10%
90
60
30
0
2.7
3.1
3.5
3.9
4.3
4.7
5.1
R
LOAD
= 16I
L
LOAD
= 1µH
180
150
120
P
OUT
(mW)
90
60
30
0
THD+N = 1%
THD+N = 10%
THD+N = 1%
5.5
2.7
3.1
3.5
3.9
4.3
4.7
5.1
5.5
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
_______________________________________________________________________________________
5
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