MAX4411EBE+TCAN [MAXIM]
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| 型号： | MAX4411EBE+TCAN |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | 暂无描述 放大器 |
| 文件： | 总18页 (文件大小：622K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-2618; Rev 1; 4/03
80mW, Fixed-Gain, DirectDrive, Stereo
Headphone Amplifier with Shutdown
General Description
Features
The MAX4411 fixed-gain, stereo headphone amplifier is
designed for portable equipment where board space is
at a premium. The MAX4411 uses a unique, patented
DirectDrive architecture to produce a ground-refer-
enced output from a single supply, eliminating the need
for large DC-blocking capacitors, saving cost, board
space, and component height. Additionally, the gain of
the amplifier is set internally (-1.5V/V, MAX4411 and
-2V/V, MAX4411B), further reducing component count.
ꢀ No Bulky DC-Blocking Capacitors Required
ꢀ Fixed -1.5V/V Gain Eliminates External Feedback
Network
MAX4411: -1.5V/V
MAX4411B: -2V/V
ꢀ Ground-Referenced Outputs Eliminate DC-Bias
Voltages on Headphone Ground Pin
ꢀ No Degradation of Low-Frequency Response Due
to Output Capacitors
The MAX4411 delivers up to 80mW per channel into a
16Ω load and has low 0.003% THD+N. An 86dB at
217Hz power-supply rejection ratio (PSRR) allows this
device to operate from noisy digital supplies without an
additional linear regulator. The MAX4411 includes 8kV
ESD protection on the headphone outputs. Com-
prehensive click-and-pop circuitry suppresses audible
clicks and pops on startup and shutdown. Independent
left/right, low-power shutdown controls make it possible
to optimize power savings in mixed-mode, mono/stereo
applications.
ꢀ 80mW per Channel into 16Ω
ꢀ Low 0.003% THD+N
ꢀ High PSRR (86dB at 217Hz)
ꢀ Integrated Click-and-Pop Suppression
ꢀ 1.8V to 3.6V Single-Supply Operation
ꢀ Low Quiescent Current (5mA)
ꢀ Independent Left/Right, Low-Power
Shutdown Controls
ꢀ Short-Circuit and Thermal-Overload Protection
ꢀ
8kV ESD-Protected Amplifier Outputs
The MAX4411 operates from a single 1.8V to 3.6V supply,
consumes only 5mA of supply current, has short-circuit
and thermal-overload protection, and is specified over the
extended -40°C to +85°C temperature range. The
MAX4411 is available in a tiny (2mm ✕ 2mm ✕ 0.6mm),
16-bump chip-scale package (UCSP™) and a 20-pin thin
QFN package (4mm ✕ 4mm ✕ 0.8mm).
ꢀ Available in Space-Saving Packages
16-Bump UCSP (2mm ✕ 2mm ✕ 0.6mm)
20-Pin Thin QFN (4mm ✕ 4mm ✕ 0.8mm)
Ordering Information
PIN/BUMP-
PACKAGE
GAIN
(V/V)
PART
TEMP RANGE
Applications
Notebook PCs
Cellular Phones
PDAs
MP3 Players
Smart Phones
Portable Audio Equipment
MAX4411EBE-T
MAX4411ETP
MAX4411BEBE-T
MAX4411BETP
-40°C to +85°C 16 UCSP-16
-40°C to +85°C 20 Thin QFN
-40°C to +85°C 16 UCSP-16
-40°C to +85°C 20 Thin QFN
-1.5
-1.5
-2
-2
UCSP is a trademark of Maxim Integrated Products, Inc.
Functional Diagram
DirectDrive OUTPUTS
ELIMINATE DC-BLOCKING
CAPACITORS
LEFT
AUDIO
INPUT
SHDNL
SHDNR
MAX4411
RIGHT
AUDIO
INPUT
FIXED GAIN ELIMINATES
EXTERNAL RESISTOR
NETWORK
Pin Configurations and Typical Application Circuit appear at end of data sheet.
________________________________________________________________ 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.
80mW, Fixed-Gain, DirectDrive, Stereo
Headphone Amplifier with Shutdown
ABSOLUTE MAXIMUM RATINGS
PGND to SGND .....................................................-0.3V to +0.3V
Output Short Circuit to GND or V ...........................Continuous
DD
PV
to SV
SS
and SV
-0.3V to +0.3V
Continuous Power Dissipation (T = +70°C)
DD
DD .................................................................
A
PV to SV .........................................................-0.3V to +0.3V
16-Bump UCSP (derate 7.4mW/°C above +70°C)........589mW
20-Pin Thin QFN (derate 16.9mW/°C above +70°C) ..1349mW
Junction Temperature......................................................+150°C
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range.............................-65°C to +150°C
Bump Temperature (soldering)
SS
PV
to PGND or SGND.........................-0.3V to +4V
DD
DD
SS
PV and SV to PGND or SGND ..........................-4V to +0.3V
SS
IN_ to SGND ................................(SV - 0.3V) to (SV
SHDN_ to SGND........................(SGND - 0.3V) to (SV
OUT_ to SGND .............................(SV - 0.3V) to (SV
C1P to PGND.............................(PGND - 0.3V) to (PV
+ 0.3V)
+ 0.3V)
+0.3V)
+ 0.3V)
SS
DD
DD
DD
DD
SS
Reflow ..........................................................................+230°C
Lead Temperature (soldering, 10s) .................................+300°C
C1N to PGND.............................(PV - 0.3V) to (PGND + 0.3V)
SS
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
(PV
= SV
= 3V, PGND = SGND = 0V, SHDNL = SHDNR = SV , C1 = C2 = 2.2µF, C = 1µF, R = ∞, T = T
to T
,
MAX
DD
DD
DD
IN
L
A
MIN
unless otherwise noted. Typical values are at T = +25°C.) (Note 1)
A
PARAMETER
SYMBOL
CONDITIONS
Guaranteed by PSRR test
MIN
TYP
MAX
UNITS
Supply Voltage Range
V
1.8
3.6
V
DD
One channel enabled
Two channels enabled
SHDNL = SHDNR = GND
3.2
5
Quiescent Supply Current
Shutdown Supply Current
I
mA
µA
DD
8.4
10
I
6
SHDN
0.7 x
V
V
IH
IL
SV
DD
SHDN_ Thresholds
V
0.3 x
SV
DD
SHDN_ Input Leakage Current
SHDN_ to Full Operation
CHARGE PUMP
-1
+1
µA
µs
t
f
175
320
SON
OSC
Oscillator Frequency
AMPLIFIERS
272
368
kHz
MAX4411
-1.55
-2.1
-1.5
-2
-1.45
-1.9
Voltage Gain
A
V/V
%
V
MAX4411B
Gain Match
∆A
1
V
MAX4411
0.7
0.75
14
2.8
3.0
19
Total Output Offset Voltage
Input Resistance
V
Input AC-coupled
mV
kΩ
OS
MAX4411B
R
10
72
IN
1.8V ≤ V
≤ 3.6V,
DD
DC (Note 2)
86
MAX4411
Power-Supply Rejection Ratio
PSRR
f
f
f
= 217Hz
= 1kHz
86
75
53
dB
RIPPLE
RIPPLE
RIPPLE
V
= 3.0V, 200mV
DD
P-P
ripple, MAX4411
(Note 3)
= 20kHz
2
_______________________________________________________________________________________
80mW, Fixed-Gain, DirectDrive, Stereo
Headphone Amplifier with Shutdown
ELECTRICAL CHARACTERISTICS (continued)
(PV
= SV
= 3V, PGND = SGND = 0V, SHDNL = SHDNR = SV , C1 = C2 = 2.2µF, C = 1µF, R = ∞, T = T
to T
,
MAX
DD
DD
DD
IN
L
A
MIN
unless otherwise noted. Typical values are at T = +25°C.) (Note 1)
A
PARAMETER
SYMBOL
CONDITIONS
≤ 3.6V,
MIN
TYP
MAX
UNITS
1.8V ≤ V
MAX4411B
DD
DC (Note 2)
69
86
Power-Supply Rejection Ratio
PSRR
f
f
f
= 217Hz
= 1kHz
86
73
51
65
80
dB
RIPPLE
RIPPLE
RIPPLE
V
= 3.0V, 200mV
DD
P-P
ripple, MAX4411B
(Note 3)
= 20kHz
R = 32Ω
THD+N ≤ 1%
L
Output Power
P
mW
%
OUT
T
= +25°C
A
R = 16Ω
55
L
R = 32Ω, P
50mW
=
=
L
OUT
0.003
0.004
Total Harmonic Distortion Plus
Noise
THD+N
f
= 1kHz
IN
R = 16Ω, P
60mW
L
OUT
R = 32Ω, P
=
MAX4411
94
95
L
OUT
Signal-to-Noise Ratio
SNR
SR
20mW, f = 1kHz,
dB
IN
MAX4411B
BW = 22Hz to 22kHz
Slew Rate
0.8
150
90
V/µs
pF
Maximum Capacitive Load
Crosstalk
C
No sustained oscillations
L
R = 16Ω, P
= 1.6mW, f = 10kHz
dB
°C
L
OUT
IN
Thermal Shutdown Threshold
Thermal Shutdown Hysteresis
ESD Protection
140
15
°C
Human Body Model (OUTR, OUTL)
8
kV
Note 1: All specifications are 100% tested at T = +25°C; temperature limits are guaranteed by design.
A
Note 2: Inputs are connected directly to GND.
Note 3: Inputs are AC-coupled to ground.
Typical Operating Characteristics
(C1 = C2 = 2.2µF, 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
0.1
1
V
= 3V
V = 1.8V
DD
L
DD
R = 32Ω
L
V
= 3V
DD
R = 16Ω
L
R = 16Ω
0.1
0.1
P
= 5mW
OUT
P
= 10mW
OUT
P
= 5mW
OUT
P
= 10mW
OUT
P
= 25mW
OUT
0.01
0.001
0.01
0.001
P
= 10mW
0.01
0.001
OUT
P
P
= 20mW
P
= 50mW
OUT
OUT
= 25mW
OUT
10
100
1k
FREQUENCY (Hz)
10k
100k
10
100
1k
10k
100k
10
100
1k
FREQUENCY (Hz)
10k
100k
FREQUENCY (Hz)
_______________________________________________________________________________________
3
80mW, Fixed-Gain, DirectDrive, Stereo
Headphone Amplifier with Shutdown
Typical Operating Characteristics (continued)
(C1 = C2 = 2.2µF, 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. OUTPUT POWER
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER
1
100
100
OUTPUTS IN
PHASE
OUTPUTS IN
PHASE
V
= 1.8V
V
= 3V
V
= 3V
DD
R = 32Ω
L
DD
R = 16Ω
L
DD
R = 16Ω
L
f
= 20Hz
f
IN
= 1kHz
IN
10
1
10
1
0.1
OUTPUTS 180°
OUT OF PHASE
P
= 5mW
OUT
OUTPUTS 180°
OUT OF PHASE
0.1
0.1
P
= 10mW
OUT
0.01
0.001
0.01
0.001
0.01
0.001
ONE CHANNEL
DRIVEN
ONE CHANNEL
DRIVEN
P
= 20mW
OUT
10
100
1k
FREQUENCY (Hz)
10k
100k
0
50
100
150
200
0
50
100
150
200
OUTPUT POWER (mW)
OUTPUT POWER (mW)
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
V
= 3V
V
= 3V
V
= 3V
DD
R = 32Ω
L
DD
R = 32Ω
DD
R = 16Ω
L
OUTPUTS IN
PHASE
OUTPUTS IN
PHASE
OUTPUTS IN
PHASE
L
f
IN
= 1kHz
f
= 20Hz
f
IN
= 10kHz
IN
10
10
10
1
1
1
OUTPUTS 180°
OUT OF PHASE
0.1
0.1
0.1
OUTPUTS 180°
OUT OF PHASE
OUTPUTS 180°
OUT OF PHASE
0.01
0.001
0.01
0.001
0.01
0.001
ONE CHANNEL
DRIVEN
ONE CHANNEL
DRIVEN
ONE CHANNEL
DRIVEN
0
50
100
150
200
0
25
50
75
100
125
0
25
50
75
100
125
OUTPUT POWER (mW)
OUTPUT POWER (mW)
OUTPUT POWER (mW)
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
OUTPUTS IN
PHASE
OUTPUTS IN
PHASE
V
= 1.8V
V
= 1.8V
DD
L
V
= 3V
DD
R = 16Ω
DD
R = 32Ω
L
R = 16Ω
L
IN
OUTPUTS IN
PHASE
f
= 20Hz
f = 1kHz
IN
f
IN
= 10kHz
10
1
10
1
10
1
OUTPUTS 180°
OUT OF PHASE
OUTPUTS 180°
OUT OF PHASE
OUTPUTS 180°
OUT OF PHASE
0.1
0.1
0.1
0.01
0.001
0.01
0.001
0.01
0.001
ONE CHANNEL
ONE CHANNEL
ONE CHANNEL
DRIVEN
DRIVEN
DRIVEN
0
10
20
30
40
50
60
0
10
20
30
40
50
60
0
25
50
75
100
125
OUTPUT POWER (mW)
OUTPUT POWER (mW)
OUTPUT POWER (mW)
4
_______________________________________________________________________________________
80mW, Fixed-Gain, DirectDrive, Stereo
Headphone Amplifier with Shutdown
Typical Operating Characteristics (continued)
(C1 = C2 = 2.2µF, 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
V
= 1.8V
V
= 1.8V
DD
R = 32Ω
L
DD
R = 16Ω
L
V
= 1.8V
DD
OUTPUTS IN
PHASE
R = 32Ω
L
f
= 1kHz
f
IN
= 10kHz
IN
f
= 20Hz
10
IN
10
10
OUTPUTS IN
PHASE
OUTPUTS IN
PHASE
1
1
1
OUTPUTS 180°
OUT OF PHASE
0.1
0.1
0.1
OUTPUTS 180°
OUT OF PHASE
OUTPUTS 180°
OUT OF PHASE
0.01
0.001
0.01
0.001
0.01
0.001
ONE CHANNEL
ONE CHANNEL
DRIVEN
DRIVEN
ONE CHANNEL
DRIVEN
0
10
20
30
40
50
60
0
10
10
10
20
30
40
50
0
10
20
30
40
50
OUTPUT POWER (mW)
OUTPUT POWER (mW)
OUTPUT POWER (mW)
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER
100
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
0
0
V
= 1.8V
DD
L
V
= 3V
= 16Ω
V
= 1.8V
= 16Ω
DD
DD
OUTPUTS IN
PHASE
-10
-20
-30
-40
-50
-60
-70
-80
-10
-20
-30
-40
-50
-60
-70
-80
R = 32Ω
R
L
R
L
f
IN
= 10kHz
10
1
OUTPUTS 180°
OUT OF PHASE
0.1
ONE CHANNEL
DRIVEN
0.01
0.001
-90
-90
-100
-100
10
100
1k
10k
100k
100
1k
10k
100k
0
10
20
30
40
50
FREQUENCY (Hz)
FREQUENCY (Hz)
OUTPUT POWER (mW)
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
CROSSTALK vs. FREQUENCY
0
-20
0
0
V
P
= 3V
= 1.6mW
R = 16Ω
DD
OUT
V
= 1.8V
= 32Ω
DD
V
R
= 3V
DD
= 32Ω
-10
-20
-30
-40
-50
-60
-70
-80
-10
-20
-30
-40
-50
-60
-70
-80
R
L
L
L
-40
-60
LEFT TO RIGHT
-80
-100
-120
-140
RIGHT TO LEFT
100
-90
-90
-100
-100
1k
FREQUENCY (Hz)
10k
100k
10
100
1k
10k
100k
10
100
1k
10k
100k
FREQUENCY (Hz)
FREQUENCY (Hz)
_______________________________________________________________________________________
5
80mW, Fixed-Gain, DirectDrive, Stereo
Headphone Amplifier with Shutdown
Typical Operating Characteristics (continued)
(C1 = C2 = 2.2µF, THD+N measurement bandwidth = 22Hz to 22kHz, T = +25°C, unless otherwise noted.)
A
OUTPUT POWER vs. SUPPLY VOLTAGE
OUTPUT POWER vs. SUPPLY VOLTAGE
OUTPUT POWER vs. SUPPLY VOLTAGE
300
200
180
160
140
120
100
80
140
f
= 1kHz
f
= 1kHz
f
= 1kHz
IN
IN
IN
INPUTS 180°
OUT OF PHASE
R
L
= 16Ω
R
L
= 16Ω
R
L
= 32Ω
120
100
250
200
150
100
50
INPUTS 180°
OUT OF PHASE
INPUTS 180°
OUT OF PHASE
THD+N = 10%
THD+N = 1%
THD+N = 1%
80
60
40
20
0
60
INPUTS
IN PHASE
INPUTS
IN PHASE
INPUTS
IN PHASE
40
20
0
0
1.8
2.1
2.4
2.7
3.0
3.3
3.6
1.8
2.1
2.4
2.7
3.0
3.3
3.6
1.8
2.1
2.4
2.7
3.0
3.3
3.6
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
OUTPUT POWER vs. LOAD RESISTANCE
OUTPUT POWER vs. SUPPLY VOLTAGE
OUTPUT POWER vs. LOAD RESISTANCE
160
140
120
100
80
180
160
140
120
100
80
250
200
150
V
f
= 3V
V
f
= 3V
DD
DD
f
= 1kHz
IN
= 1kHz
= 1kHz
IN
IN
R
L
= 32Ω
INPUTS 180°
THD+N = 1%
THD+N = 10%
THD+N = 10%
OUT OF PHASE
INPUTS 180°
INPUTS 180°
60
100
50
0
INPUTS
IN PHASE
OUT OF PHASE
OUT OF PHASE
60
40
20
0
40
20
0
INPUTS
IN PHASE
INPUTS
IN PHASE
10
100
1k
10k
100k
1.8
2.1
2.4
2.7
3.0
3.3
3.6
10
100
1k
10k
100k
LOAD RESISTANCE (Ω)
SUPPLY VOLTAGE (V)
LOAD RESISTANCE (Ω)
POWER DISSIPATION
vs. OUTPUT POWER
OUTPUT POWER vs. LOAD RESISTANCE
OUTPUT POWER vs. LOAD RESISTANCE
70
60
50
40
30
20
10
0
400
350
300
250
200
150
100
50
45
40
35
30
25
20
15
10
5
INPUTS
IN PHASE
V
f
= 1.8V
V
f
= 1.8V
DD
DD
f
= 1kHz
= 16Ω
= 3V
IN
L
DD
OUT
= 1kHz
= 1kHz
IN
IN
R
V
INPUTS 180°
OUT OF PHASE
INPUTS 180°
OUT OF PHASE
THD+N = 10%
THD+N = 1%
P
= P
+ P
OUTR
OUTL
INPUTS IN
PHASE
INPUTS 180°
OUT OF PHASE
INPUTS IN
PHASE
0
0
10
100
1k
10k
100k
0
40
80
120
160
200
10
100
1k
10k
100k
LOAD RESISTANCE (Ω)
OUTPUT POWER (mW)
LOAD RESISTANCE (Ω)
6
_______________________________________________________________________________________
80mW, Fixed-Gain, DirectDrive, Stereo
Headphone Amplifier with Shutdown
Typical Operating Characteristics (continued)
(C1 = C2 = 2.2µF, THD+N measurement bandwidth = 22Hz to 22kHz, T = +25°C, unless otherwise noted.)
A
POWER DISSIPATION
vs. OUTPUT POWER
POWER DISSIPATION
vs. OUTPUT POWER
POWER DISSIPATION
vs. OUTPUT POWER
180
140
120
100
70
60
50
INPUTS
IN PHASE
INPUTS
IN PHASE
f
= 1kHz
IN
INPUTS
IN PHASE
160
140
120
100
80
R
L
= 16Ω
V
P
= 1.8V
DD
OUT
= P
+ P
OUTR
OUTL
INPUTS 180°
OUT OF PHASE
INPUTS 180°
OUT OF PHASE
INPUTS 180°
OUT OF PHASE
80
60
40
20
0
40
30
20
10
0
60
f
= 1kHz
= 32Ω
IN
f
= 1kHz
= 32Ω
= 1.8V
IN
L
DD
OUT
R
L
40
R
V
V
P
= 3V
DD
OUT
20
= P
+ P
OUTR
OUTL
P
= P
+ P
OUTL OUTR
0
0
40
80
120
160
200
0
10
20
30
40
50
60
0
10
20
30
40
50
60
OUTPUT POWER (mW)
OUTPUT POWER (mW)
OUTPUT POWER (mW)
CHARGE-PUMP OUTPUT RESISTANCE
vs. SUPPLY VOLTAGE
OUTPUT POWER vs. CHARGE-PUMP
CAPACITANCE AND LOAD RESISTANCE
GAIN FLATNESS vs. FREQUENCY
10
10
5
90
80
70
60
50
C1 = C2 = 2.2µF
C1 = C2 = 1µF
V
I
= GND
PVSS
NO LOAD
IN_
= 10mA
8
6
4
2
0
0
-5
A
= -1.5V/V
A = -2V/V
V
V
C1 = C2 = 0.68µF
C1 = C2 = 0.47µF
-10
40
30
20
10
0
-15
-20
-25
-30
f
= 1kHz
IN
THD+N = 1%
V
= 3V
DD
INPUTS IN PHASE
R = 16Ω
L
1.8
2.1
2.4
2.7
3.0
3.3
3.6
10
100
1k
10k
100k
1M
10
20
30
40
50
SUPPLY VOLTAGE (V)
FREQUENCY (Hz)
LOAD RESISTANCE (Ω)
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
SHUTDOWN SUPPLY CURRENT
vs. SUPPLY VOLTAGE
OUTPUT SPECTRUM vs. FREQUENCY
10
8
0
-20
10
V
IN
R
= 1V
P-P
OUT
= 1kHz
SHDNL = SHDNR = GND
f
= 32Ω
L
8
6
4
2
0
-40
6
-60
4
-80
2
-100
-120
0
0
0.9
1.8
2.7
3.6
0.1
1
10
100
0
0.9
1.8
2.7
3.6
SUPPLY VOLTAGE (V)
FREQUENCY (kHz)
SUPPLY VOLTAGE (V)
_______________________________________________________________________________________
7
80mW, Fixed-Gain, DirectDrive, Stereo
Headphone Amplifier with Shutdown
Typical Operating Characteristics (continued)
(C1 = C2 = 2.2µF, THD+N measurement bandwidth = 22Hz to 22kHz, T = +25°C, unless otherwise noted.)
A
EXITING SHUTDOWN
POWER-UP/DOWN WAVEFORM
MAX4411 toc41
MAX4411 toc40
3V
0V
2V/div
V
DD
SHDNR
OUTR
OUT_
10mV/div
20dB/div
-100dB
500mV/div
OUT_FFT
200µs/div
200ms/div
FFT: 25Hz/div
f
= 1kHz
IN
R = 32Ω
IN_
R = 32Ω
SHDNL = GND
L
L
V
= GND
Pin Description
PIN
BUMP
UCSP
A4
NAME
FUNCTION
QFN
1
2
3
C1P
PGND
C1N
Flying Capacitor Positive Terminal
B4
Power Ground. Connect to ground (0V).
Flying Capacitor Negative Terminal
C4
4, 6, 8, 12,
16, 20
—
N.C.
No Connection. Not internally connected.
5
D4
D3
D2
D1
C2
C1
B1
A1
A2
B2
PV
SV
Charge-Pump Output
SS
7
Amplifier Negative Power Supply. Connect to PV
.
SS
SS
9
OUTL
SV
Left-Channel Output
10
11
13
14
15
17
18
Amplifier Positive Power Supply. Connect to positive supply (1.8V to 3.6V).
Right-Channel Output
DD
OUTR
INL
Left-Channel Audio Input
SHDNR
INR
Active-Low Right-Channel Shutdown. Connect to V
Right-Channel Audio Input
for normal operation.
DD
SGND
SHDNL
Signal Ground. Connect to ground (0V).
Active-Low Left-Channel Shutdown. Connect to V for normal operation.
DD
Charge-Pump Power Supply. Powers charge-pump inverter, charge-pump logic, and
oscillator. Connect to positive supply (1.8V to 3.6V).
19
A3
PV
DD
—
—
EP
Exposed Paddle. Leave this connection floating. Do not tie to either GND or V
.
DD
8
_______________________________________________________________________________________
80mW, Fixed-Gain, DirectDrive, Stereo
Headphone Amplifier with Shutdown
Detailed Description
The MAX4411 fixed-gain, stereo headphone driver fea-
tures Maxim’s patented DirectDrive architecture, elimi-
nating the large output-coupling capacitors required by
conventional single-supply headphone drivers. The
device consists of two 80mW Class AB headphone dri-
vers, internal feedback network, undervoltage lockout
(UVLO)/shutdown control, charge pump, and compre-
hensive click-and-pop suppression circuitry (see Typical
Application Circuit). The charge pump inverts the posi-
V
DD
V
/2
V
DD
OUT
GND
tive supply (PV ), creating a negative supply (PV ).
DD
SS
The headphone drivers operate from these bipolar sup-
plies with their outputs biased about GND (Figure 1). The
drivers have almost twice the supply range compared to
other 3V single-supply drivers, increasing the available
output power. The benefit of this GND bias is that the dri-
ver outputs do not have a DC component typically
CONVENTIONAL DRIVER-BIASING SCHEME
+V
DD
V
/2. The large DC-blocking capacitors required with
DD
conventional headphone drivers are unnecessary, thus
conserving board space, system cost, and improving
frequency response.
V
OUT
GND
Each channel has independent left/right, active-low
shutdown controls, optimizing power savings in mixed-
mode, mono/stereo operation. The device features an
undervoltage lockout that prevents operation from an
insufficient power supply and click-and-pop suppres-
sion that eliminates audible transients on startup and
shutdown. Additionally, the MAX4411 features thermal-
overload and short-circuit protection and can withstand
8kV ESD strikes on the output pins.
-V
DD
DirectDrive BIASING SCHEME
Figure 1. Conventional Driver Output Waveform vs. MAX4411
Output Waveform
Fixed Gain
The MAX4411 utilizes an internally fixed gain configura-
tion of either -1.5V/V (MAX4411) or -2V/V (MAX4411B).
All gain-setting resistors are integrated into the device,
reducing external component count. The internally set
gain, in combination with DirectDrive, results in a head-
phone amplifier that requires only five tiny 1µF capaci-
tors to complete the amplifier circuit: two for the charge
pump, two for audio input coupling, and one for power-
supply bypassing (see Typical Application Circuit).
age. This allows the MAX4411 outputs to be biased
about GND, almost doubling dynamic range while
operating from a single supply. With no DC component,
there is no need for the large DC-blocking capacitors.
Instead of two large (220µF, typ) tantalum capacitors,
the MAX4411 charge pump requires two small ceramic
capacitors, conserving board space, reducing cost,
and improving the frequency response of the head-
phone driver. See the Output Power vs. Charge-Pump
Capacitance and Load Resistance graph in the Typical
Operating Characteristics for details of the possible
capacitor sizes. There is a low DC voltage on the driver
outputs due to amplifier offset. However, the offset of
the MAX4411 is typically 0.7mV, which, when com-
bined with a 32Ω load, results in less than 23µA of DC
current flow to the headphones.
DirectDrive
Conventional single-supply headphone drivers have their
outputs biased about a nominal DC voltage (typically half
the supply) for maximum dynamic range. Large coupling
capacitors are needed to block this DC bias from the
headphone. Without these capacitors, a significant
amount of DC current flows to the headphone, resulting
in unnecessary power dissipation and possible damage
to both headphone and headphone driver.
Previous attempts to eliminate the output-coupling capac-
itors involved biasing the headphone return (sleeve) to
the DC-bias voltage of the headphone amplifiers. This
Maxim’s patented DirectDrive architecture uses a
charge pump to create an internal negative supply volt-
_______________________________________________________________________________________
9
80mW, Fixed-Gain, DirectDrive, Stereo
Headphone Amplifier with Shutdown
MICROPHONE
LOW-FREQUENCY ROLLOFF
(R = 16Ω)
BIAS
L
MICROPHONE
AMPLIFIER
0
-3
MICROPHONE
AMPLIFIER
OUTPUT
DirectDrive
330µF
220µF
100µF
-6
-9
-12
AUDIO
INPUT
-15
-18
33µF
-21
-24
MAX4411
AUDIO
INPUT
-27
-30
10
100
1k
FREQUENCY (Hz)
10k
100k
HEADPHONE DRIVER
Figure 2. Earbud Speaker/Microphone Combination Headset
Configuration
Figure 3. Low-Frequency Attenuation for Common DC-Blocking
Capacitor Values
method raises some issues:
1
f
=
−3dB
•
The sleeve is typically grounded to the chassis.
Using this biasing approach, the sleeve must be
isolated from system ground, complicating product
design.
2πR C
L
OUT
where R is the impedance of the headphone and
L
C
is the value of the DC-blocking capacitor.
OUT
•
•
During an ESD strike, the driver’s ESD structures
are the only path to system ground. Thus, the driver
must be able to withstand the full ESD strike.
The highpass filter is required by conventional sin-
gle-ended, single power-supply headphone drivers
to block the midrail DC-bias component of the audio
signal from the headphones. The drawback to the
filter is that it can attenuate low-frequency signals.
When using the headphone jack as a line out to other
equipment, the bias voltage on the sleeve may con-
flict with the ground potential from other equipment,
resulting in possible damage to the drivers.
Larger values of C
reduce this effect but result
OUT
in physically larger, more expensive capacitors.
Figure 3 shows the relationship between the size of
•
When using a combination microphone and speaker
headset, the microphone typically requires a GND
reference. The driver DC bias on the sleeve conflicts
with the microphone requirements (Figure 2).
C
and the resulting low-frequency attenuation.
OUT
Note that the -3dB point for a 16Ω headphone with a
100µF blocking capacitor is 100Hz, well within the nor-
mal audio band, resulting in low-frequency attenuation
of the reproduced signal.
Low-Frequency Response
In addition to the cost and size disadvantages of the DC-
blocking capacitors required by conventional head-
phone amplifiers, these capacitors limit the amplifier’s
low-frequency response and can distort the audio signal:
2) The voltage coefficient of the DC-blocking capacitor
contributes distortion to the reproduced audio signal
as the capacitance value varies as the function of
the voltage across the capacitor changes. At low
frequencies, the reactance of the capacitor domi-
nates at frequencies below the -3dB point and the
voltage coefficient appears as frequency-depen-
dent distortion. Figure 4 shows the THD+N intro-
1) The impedance of the headphone load and the DC-
blocking capacitor forms a highpass filter with the
-3dB point set by:
10 ______________________________________________________________________________________
80mW, Fixed-Gain, DirectDrive, Stereo
Headphone Amplifier with Shutdown
6µA. The charge pump is enabled once either SHDN_
input is driven high.
ADDITIONAL THD+N DUE
TO DC-BLOCKING CAPACITORS
Click-and-Pop Suppression
10
1
In conventional single-supply audio drivers, the output-
coupling capacitor is a major contributor of audible
clicks and pops. Upon startup, the driver charges the
coupling capacitor to its bias voltage, typically half the
supply. Likewise, on shutdown, the capacitor is dis-
charged to GND. This results in a DC shift across the
capacitor, which in turn, appears as an audible transient
at the speaker. Since the MAX4411 does not require
output-coupling capacitors, this does not arise.
0.1
TANTALUM
0.01
0.001
0.0001
Additionally, the MAX4411 features extensive click-and-
pop suppression that eliminates any audible transient
sources internal to the device. The Power-Up/Down
Waveform in the Typical Operating Characteristics
shows that there are minimal spectral components in the
audible range at the output upon startup or shutdown.
ALUM/ELEC
10
100
1k
10k
100k
FREQUENCY (Hz)
Figure 4. Distortion Contributed by DC-Blocking Capacitors
In most applications, the output of the preamplifier dri-
ving the MAX4411 has a DC bias of typically half the
supply. At startup, the input-coupling capacitor is
charged to the preamplifier’s DC-bias voltage through
duced by two different capacitor dielectric types.
Note that below 100Hz, THD+N increases rapidly.
the R of the MAX4411, resulting in a DC shift across
F
The combination of low-frequency attenuation and fre-
quency-dependent distortion compromises audio repro-
duction in portable audio equipment that emphasizes
low-frequency effects such as multimedia laptops, as
well as MP3, CD, and DVD players. By eliminating the
DC-blocking capacitors through DirectDrive technology,
these capacitor-related deficiencies are eliminated.
the capacitor and an audible click/pop. Delaying the
rise of the SHDN_ signals 4 to 5 time constants (80ms
to 100ms) based on R and C relative to the startup
IN
IN,
of the preamplifier, eliminates this click/pop caused by
the input filter.
Applications Information
Charge Pump
The MAX4411 features a low-noise charge pump. The
320kHz switching frequency is well beyond the audio
range, and thus does not interfere with the audio sig-
nals. The switch drivers feature a controlled switching
speed that minimizes noise generated by turn-on and
turn-off transients. By limiting the switching speed of the
charge pump, the di/dt noise caused by the parasitic
bond wire and trace inductance is minimized. Although
not typically required, additional high-frequency noise
attenuation can be achieved by increasing the size of
C2 (see Typical Application Circuit).
Power Dissipation
Under normal operating conditions, linear power ampli-
fiers can 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:
T
− T
A
J(MAX)
P
=
DISSPKG(MAX)
θ
JA
where T
is +150°C, T is the ambient tempera-
A
J(MAX)
ture, and θ is the reciprocal of the derating factor in
JA
°C/W as specified in the Absolute Maximum Ratings
section. For example, θ
+59.3°C/W.
Shutdown
The MAX4411 features two shutdown controls allowing
either channel to be shut down or muted independently.
SHDNL controls the left channel while SHDNR controls
the right channel. Driving either SHDN_ low disables
the respective channel, sets the driver output imped-
ance to 1kΩ, and reduces the supply current. When
both SHDN_ inputs are driven low, the charge pump is
also disabled, further reducing supply current draw to
of the QFN package is
JA
The MAX4411 has two power dissipation sources, the
charge pump and the two drivers. If the power dissipa-
tion for a given application exceeds the maximum
allowed for a given package, either reduce V
,
DD
increase load impedance, decrease the ambient tem-
perature, or add heatsinking to the device. Large
______________________________________________________________________________________ 11
80mW, Fixed-Gain, DirectDrive, Stereo
Headphone Amplifier with Shutdown
PV is roughly proportional to PV
and is not a regu-
SS
DD
lated voltage. The charge-pump output impedance
must be taken into account when powering other
OUTPUT POWER vs. SUPPLY VOLTAGE
300
devices from PV . The charge-pump output imped-
SS
f
= 1kHz
IN
ance plot appears in the Typical Operating
Characteristics. For best results, use 2.2µF charge-
pump capacitors.
INPUTS 180°
OUT OF PHASE
R
L
= 16Ω
250
200
150
100
50
THD+N = 10%
Component Selection
Input Filtering
The input capacitor (C ), in conjunction with the inter-
IN
nal R
forms a highpass filter that removes the DC
IN,
INPUTS
IN PHASE
bias from an incoming signal (see Typical Application
Circuit). 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:
0
1.8
2.1
2.4
2.7
3.0
3.3
3.6
SUPPLY VOLTAGE (V)
1
f
=
−3dB
2πR C
Figure 5. Output Power vs. Supply Voltage with Inputs In/Out of
Phase
IN IN
R
is the amplifier’s internal input resistance value
IN
output, supply, and ground traces improve the maxi-
mum power dissipation in the package.
given in the Electrical Characteristics. Choose the C
IN
such that f
interest. Setting f
frequency response. Use capacitors whose dielectrics
have low-voltage coefficients, such as tantalum or
aluminum electrolytic ones. Capacitors with high-voltage
coefficients, such as ceramics, may result in increased
distortion at low frequencies.
is well below the lowest frequency of
-3dB
too high affects the amplifier’s low-
-3dB
Thermal-overload protection limits total power dissipa-
tion in the MAX4411. When the junction temperature
exceeds +140°C, the thermal protection circuitry dis-
ables the amplifier output stage. The amplifiers are
enabled once the junction temperature cools by 15°C.
This results in a pulsing output under continuous thermal-
overload conditions.
Charge-Pump Capacitor Selection
Use capacitors with an ESR less than 100mΩ for opti-
mum performance. Low-ESR ceramic capacitors mini-
mize the output resistance of the charge pump. For best
performance over the extended temperature range,
select capacitors with an X7R dielectric. Table 1 lists sug-
gested manufacturers.
Output Power
The device has been specified for the worst-case sce-
nario—when both inputs are in phase. Under this con-
dition, the drivers simultaneously draw current from the
charge pump, leading to a slight loss in headroom of
V
. In typical stereo audio applications, the left and
SS
right signals have differences in both magnitude and
phase, subsequently leading to an increase in the max-
imum attainable output power. Figure 5 shows the two
extreme cases for in and out of phase. In reality, the
available power lies between these extremes.
Flying Capacitor (C1)
The value of the flying capacitor (C1) affects the charge
pump’s load regulation and output resistance. A C1
value that is too small degrades the device’s ability to
provide sufficient current drive, which leads to a loss of
output voltage. Increasing the value of C1 improves
load regulation and reduces the charge-pump output
resistance to an extent. See the Output Power vs.
Charge-Pump Capacitance and Load Resistance
graph in the Typical Operating Characteristics. Above
2.2µF, the on-resistance of the switches and the ESR of
C1 and C2 dominate.
Powering Other Circuits from a
Negative Supply
An additional benefit of the MAX4411 is the internally
generated, negative supply voltage (PV ). This volt-
SS
age provides the ground-referenced output level. PV
SS
can, however, also be used to power other devices
within a design limit current drawn from PV to 5mA;
SS
Hold Capacitor (C2)
exceeding this affects the headphone driver operation.
A typical application is a negative supply to adjust the
contrast of LCD modules.
The hold capacitor value and ESR directly affect the
ripple at PV . Increasing the value of C2 reduces
SS
12 ______________________________________________________________________________________
80mW, Fixed-Gain, DirectDrive, Stereo
Headphone Amplifier with Shutdown
Table 1. Suggested Capacitor Manufacturers
SUPPLIER
Taiyo Yuden
TDK
PHONE
FAX
WEBSITE
www.t-yuden.com
www.component.tdk.com
800-348-2496
847-803-6100
847-925-0899
847-390-4405
Note: Please indicate you are using the MAX4411 when contacting these component suppliers.
output ripple. Likewise, decreasing the ESR of C2
reduces both ripple and output resistance. Lower
capacitance values can be used in systems with low
maximum output power levels. See the Output Power
vs. Charge-Pump Capacitance and Load Resistance
graph in the Typical Operating Characteristics.
device. Connect PV
and SV
together at the
SS
SS
device. Bypassing of both supplies is accomplished by
charge-pump capacitors C2 and C3 (see Typical
Application Circuit). Place capacitors C2 and C3 as
close to the device as possible. Route PGND and all
traces that carry switching transients away from SGND
and the traces and components in the audio signal
path.
Power-Supply Bypass Capacitor
The power-supply bypass capacitor (C3) lowers the out-
put impedance of the power supply, and reduces the
impact of the MAX4411’s charge-pump switching tran-
The QFN package features an exposed paddle that
improves thermal efficiency of the package. However,
the MAX4411 does not require additional heatsinking.
Ensure that the exposed paddle is isolated from
sients. Bypass PV
with C3, the same value as C1, and
DD
place it physically close to the PV and PGND pins.
DD
GND or V . Do not connect the exposed paddle to
DD
Adding Volume Control
The addition of a digital potentiometer provides simple
volume control. Figure 6 shows the MAX4411 with the
MAX5408 dual log taper digital potentiometer used as
an input attenuator. Connect the high terminal of the
MAX5408 to the audio input, the low terminal to
GND or V
.
DD
When using the MAX4411 in a UCSP package, make
sure the traces to OUTR (bump C2) are wide enough to
handle the maximum expected current flow. Multiple
traces may be necessary.
ground, and the wiper to C . Setting the wiper to the
IN
UCSP Applications Information
top position passes the audio signal unattenuated.
Setting the wiper to the lowest position fully attenuates
the input.
For the latest application details on UCSP construction,
dimensions, tape carrier information, printed circuit
board techniques, bump-pad layout, and recommend-
ed reflow temperature profile, as well as the latest infor-
mation on reliability testing results, go to Maxim’s
website at www.maxim-ic.com/ucsp and look up the
Application Note: UCSP–A Wafer-Level Chip-Scale
Package.
Layout and Grounding
Proper layout and grounding are essential for optimum
performance. Connect PGND and SGND together at a
single point on the PC board. Connect all components
associated with the charge pump (C2 and C3) to the
PGND plane. Connect PV
and SV
together at the
DD
DD
5
6
H0
LEFT AUDIO
INPUT
C
IN
13
9
W0A
7
INL
OUTL
L0
MAX4411
MAX5408
RIGHT AUDIO
INPUT
H1
L1
12
C
IN
15
11
10
W1A
INR
OUTR
11
Figure 6. MAX4411 and MAX5408 Volume Control Circuit
______________________________________________________________________________________ 13
80mW, Fixed-Gain, DirectDrive, Stereo
Headphone Amplifier with Shutdown
System Diagram
V
DD
0.1µF
15kΩ
0.1µF
15kΩ
INR
DD
OUTR+
OUTR-
V
PV
DD
0.1µF
MAX9710
1µF
BIAS
SHDN
INL
AUX_IN
1µF
OUT
OUTL-
OUTL+
0.1µF
15kΩ
MAX4060
V
CC
15kΩ
CODEC
BIAS
V
2.2kΩ
10kΩ
10kΩ
CC
0.1µF
0.1µF
IN-
IN+
IN-
V
CC
Q
Q
MAX961
100kΩ
100kΩ
0.1µF
IN+
SHDNL
SHDNR
1µF
1µF
OUTL
MAX4411
INL
INR
V
CC
OUTR
PV
SV
SS
SS
PV
SV
DD
DD
1µF
C1P
CIN
1µF
1µF
14 ______________________________________________________________________________________
80mW, Fixed-Gain, DirectDrive, Stereo
Headphone Amplifier with Shutdown
Typical Application Circuit
1.8V TO 3.6V
C
IN
1µF
LEFT
CHANNEL
AUDIO IN
C3
1µF
10
(D1)
13
(C1)
18
(B2)
14
(B1)
19
(A3)
PV
SV
DD
DD
SHDNL
SHDNR
INL
R
F*
R
SV
DD
IN
14kΩ
9
(D2)
OUTL
HEADPHONE
JACK
UVLO/
SHUTDOWN
CONTROL
1
(A4)
C1P
SV
SS
CHARGE
PUMP
CLICK-AND-POP
SUPPRESSION
C1
1µF
SGND
3
(C4) C1N
SV
DD
SGND
11
(C2)
OUTR
R
IN
14kΩ
MAX4411
SV
SS
R
F
PV
SV
7
SS
5
PGND
2
(B4)
SGND
17
(A2)
INR
15
(A1)
SS
(D4)
(D3)
C2
1µF
C
IN
1µF
RIGHT
CHANNEL
AUDIO IN
*MAX4411: 21kΩ, MAX4411B: 28kΩ
( ) UCSP BUMPS.
______________________________________________________________________________________ 15
80mW, Fixed-Gain, DirectDrive, Stereo
Headphone Amplifier with Shutdown
Pin Configurations
MAX4411
TOP VIEW
(BUMPS SIDE
DOWN)
1
2
3
4
TOP VIEW
A
B
C
D
INR
SGND
PV
C1P
DD
1
2
3
4
5
C1P
INR 15
SHDNR 14
INL 13
PGND
C1N
N.C.
PGND
C1N
SHDNR
INL
SHDNL
OUTR
MAX4411
N.C. 12
11
OUTR
PV
SS
SV
DD
OUTL
SV
SS
PV
SS
UCSP (B16-2)
QFN
Chip Information
TRANSISTOR COUNT: 4295
PROCESS: BiCMOS
16 ______________________________________________________________________________________
80mW, Fixed-Gain, DirectDrive, Stereo
Headphone Amplifier with Shutdown
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
______________________________________________________________________________________ 17
80mW, Fixed-Gain, DirectDrive, Stereo
Headphone Amplifier with Shutdown
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
PACKAGE OUTLINE
12,16,20,24L QFN THIN, 4x4x0.8 mm
21-0139
A
PACKAGE OUTLINE
12,16,20,24L QFN THIN, 4x4x0.8 mm
21-0139
A
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.
18 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2003 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
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Audio Amplifier, 0.08W, 2 Channel(s), 1 Func, BICMOS, 4 X 4 MM, 0.80 MM HEIGHT, LEAD FREE, MO-220WGGD-1, QFN-20
MAXIM
MAX4412
Low-Cost, Low-Power, Ultra-Small, 3V/5V, 500MHz Single-Supply Op Amps with Rail-to-Rail Outputs
MAXIM
MAX4412EUK-T
Low-Cost, Low-Power, Ultra-Small, 3V/5V, 500MHz Single-Supply Op Amps with Rail-to-Rail Outputs
MAXIM
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