Data Sheet
FEATURES
Digital I²S interface with high precision 24-bit data
High SNR of 61 dBA
High sensitivity of −26 dBFS
Flat frequency response from 60 Hz to 15 kHz
Low current consumption of 1.4 mA
High PSR of −75 dBFS
Small 4.72 mm × 3.76 mm × 1 mm surface-mount package
Compatible with Sn/Pb and Pb-free solder processes
RoHS/WEEE compliant
Omnidirectional Microphone with
Bottom Port and I
2
S Digital Output
ADMP441
FUNCTIONAL BLOCK DIAGRAM
ADMP441
ADC
FILTER
I
2
S
SERIAL
PORT
SCK
SD
WS
POWER
MANAGEMENT
HARDWARE
CONTROL
GND
GND
GND
CHIPEN
V
DD
L/R
Figure 1.
APPLICATIONS
Teleconferencing systems
Gaming consoles
Mobile devices
Laptops
Tablets
Security systems
09568-001
BOTTOM
TOP
Figure 2. Isometric Views of
ADMP441
Microphone Package
GENERAL DESCRIPTION
The
ADMP441
1
is a high performance, low power, digital output,
omnidirectional MEMS microphone with a bottom port. The
complete
ADMP441
solution consists of a MEMS sensor, signal
conditioning, an analog-to-digital converter, antialiasing filters,
power management, and an industry standard 24-bit I2S inter-
face. The I2S interface allows the
ADMP441
to connect directly
to digital processors, such as DSPs and microcontrollers, with-
out the need for an audio codec in the system.
The
ADMP441
has a high SNR and high sensitivity, making it
an excellent choice for far field applications. The ADMP441 has
a flat wideband frequency response, resulting in natural sound
with high intelligibility. A built-in particle filter provides high
reliability.
The
ADMP441
is available in a thin 4.72 mm × 3.76 mm ×
1 mm surface-mount package. It is reflow solder compatible
with no sensitivity degradation. The
ADMP441
is halide free.
1
Protected by U.S. Patents 7,449,356; 7,825,484; 7,885,423; and 7,961,897. Other patents are pending.
Rev. A
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.461.3113 ©2011–2012 Analog Devices, Inc. All rights reserved.
09568-015
ADMP441
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications....................................................................................... 1
Functional Block Diagram .............................................................. 1
General Description ......................................................................... 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
I2S Digital Input/Output.............................................................. 4
Timing Diagram ........................................................................... 4
Absolute Maximum Ratings............................................................ 5
ESD Caution.................................................................................. 5
Pin Configuration and Function Descriptions............................. 6
Typical Performance Characteristics ............................................. 7
Theory of Operation ........................................................................ 8
Data Sheet
Understanding Sensitivity ............................................................8
Power Management ......................................................................8
Startup.............................................................................................8
I2S Data Interface ..........................................................................8
Digital Filter Characteristics ..................................................... 10
Applications Information .............................................................. 11
Power Supply Decoupling ......................................................... 11
Handling Instructions................................................................ 11
Supporting Documentation...................................................... 11
Layout and Design Recommendations........................................ 12
Outline Dimensions ....................................................................... 13
Ordering Guide .......................................................................... 13
REVISION HISTORY
1/12—Rev. 0 to Rev. A
Changes to Circuit Note Title ....................................................... 11
Updated Outline Dimensions ....................................................... 13
Deleted Figure 18............................................................................ 13
10/11—Revision 0: Initial Version
Rev. A | Page 2 of 16
Data Sheet
SPECIFICATIONS
ADMP441
T
A
= 25°C, V
DD
= 2.4 V, SCK = 3.072 MHz, SPL = 104 dB (3.16 Pa rms), unless otherwise noted. All minimum and maximum
specifications are guaranteed. Typical specifications are not guaranteed.
Table 1.
Parameter
PERFORMANCE
Directionality
Sensitivity at 94 dB SPL
1
Signal-to-Noise Ratio
Equivalent Input Noise
Dynamic Range
Frequency Response
2
Symbol
Test Conditions/Comments
Min
Typ
Omni
−26
61
33
87
60
15
−3/+2
−75
120
−87
1.8
3.3
Max
Unit
SNR
EIN
Total Harmonic Distortion
Power Supply Rejection
Maximum Acoustic Input
Noise Floor
POWER SUPPLY
Supply Voltage
Supply Current
V
DD
= 1.8 V
Normal Mode
Standby
Power-Down
V
DD
= 3.3 V
Normal Mode
Standby
Power-Down
DIGITAL FILTER
Group Delay
THD
PSR
1 kHz, 104 dB SPL
20 kHz bandwidth, A-weighted
20 kHz bandwidth, A-weighted
Derived from EIN and maximum acoustic input
Low frequency –3 dB point
High frequency –3 dB point
Deviation limits from flat response within pass band
104 dB SPL
217 Hz, 100 mV p-p square wave superimposed on V
DD
Peak
20 Hz to 20 kHz, A-weighted, rms
−29
−23
3
dBFS
dBA
dBA SPL
dB
Hz
kHz
dB
%
dBFS
dB SPL
dBFS
V
V
DD
I
DD
1.4
1.6
0.8
2
2.5
0.8
4.5
mA
mA
μA
mA
mA
μA
sec
μs
μs
dB
dB
kHz
2.2
f
S
= 48 kHz
f
S
= 16 kHz
Pass-Band Ripple
Stop-Band Attenuation
Pass Band
1
17.25/f
S
359
1078
±0.04
60
20.3
0.423 × f
S
The peak-to-peak amplitude is relative to peak-to-peak amplitude of 2
24
− 1. The stimulus is a 104 dB SPL sinusoid having rms amplitude of 3.1623 Pa. Sensitivity is
relative to 1 Pa.
2
See Figure 6 and Figure 8.
Rev. A | Page 3 of 16
ADMP441
I²S DIGITAL INPUT/OUTPUT
–40°C < T
A
< +85°C, 1.8 V < V
DD
< 3.3 V, unless otherwise noted.
Table 2.
Parameter
DIGITAL INPUT
Voltage Input Low (L/R, WS, SCK)
Voltage Input High (L/R, WS, SCK)
SD DIGITAL OUTPUT
Voltage Output Low
Voltage Output Low
Voltage Output High
Voltage Output High
Voltage Output Low
Voltage Output Low
Voltage Output High
Voltage Output High
1
Data Sheet
Symbol
V
IL
V
IH
V
OL
V
OL
V
OH
V
OH
V
OL
V
OL
V
OH
V
OH
Test Conditions/Comments
Min
0
0.7 × V
DD
Limit
1
Max
0.25 × V
DD
Unit
V
V
V
V
V
V
V
V
V
V
V
DD
0.1 × V
DD
0.3 × V
DD
V
DD
= 1.8 V, I
SINK
= 0.25 mA
V
DD
= 1.8 V, I
SINK
= 0.7 mA
V
DD
= 1.8 V, I
SINK
= 0.7 mA
V
DD
= 1.8 V, I
SINK
= 0.25 mA
V
DD
= 3.3 V, I
SINK
= 0.5 mA
V
DD
= 3.3 V, I
SINK
= 1.7 mA
V
DD
= 3.3 V, I
SINK
= 1.7 mA
V
DD
= 3.3 V, I
SINK
= 0.5 mA
0.7 × V
DD
0.9 × V
DD
0.1 × V
DD
0.3 × V
DD
0.7 × V
DD
0.9 × V
DD
Limits based on characterization results; not production tested.
Table 3. Serial Data Port Timing Specifications
Parameter
t
SCH
t
SCL
t
SCP
f
SCK
t
WSS
t
WSH
f
WS
Description
SCK high
SCK low
SCK period
SCK frequency
WS setup
WS hold
WS frequency
Min
50
50
312
0.5
0
20
7.8
Max
Unit
ns
ns
ns
MHz
ns
ns
kHz
3.2
49.3
TIMING DIAGRAM
t
SCP
t
SCH
SCK
t
WSS
WS
t
SCL
t
WSH
SD
Figure 3. Serial Data Port Timing
Rev. A | Page 4 of 16
09568-103
Data Sheet
ABSOLUTE MAXIMUM RATINGS
Table 4.
Parameter
Supply Voltage (V
DD
)
Sound Pressure Level
Mechanical Shock
Vibration
Operating Temperature Range
Digital Pin Input Voltage
Rating
−0.3 V to +3.6 V
160 dB
10,000
g
Per MIL-STD-883 Method
2007, Test Condition B
−40°C to +85°C
−0.3 V to V
DD
+ 0.3 V or 3.6 V,
whichever is less
ADMP441
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
ESD CAUTION
T
P
RAMP-UP
T
L
t
P
CRITICAL ZONE
T
L
TO T
P
TEMPERATURE
T
SMAX
T
SMIN
t
L
PREHEAT
t
S
RAMP-DOWN
t
25°C
TO PEAK
TIME
Figure 4. Recommended Soldering Profile Limits
Table 5. Recommended Soldering Profile Limits
Profile Feature
Average Ramp Rate (T
L
to T
P
)
Preheat
Minimum Temperature (T
SMIN
)
Maximum Temperature (T
SMAX
)
Time (T
SMIN
to T
SMAX
), t
S
Ramp-Up Rate (T
SMAX
to T
L
)
Time Maintained Above Liquidous (t
L
)
Liquidous Temperature (T
L
)
Peak Temperature (T
P
)
Time Within 5°C of Actual Peak Temperature (t
P
)
Ramp-Down Rate
Time 25°C (t
25°C
) to Peak Temperature
Sn63/Pb37
1.25°C/sec max
100°C
150°C
60 sec to 75 sec
1.25°C/sec
45 sec to 75 sec
183°C
215°C +3°C/−3°C
20 sec to 30 sec
3°C/sec max
5 minute max
Pb-Free
1.25°C/sec max
100°C
200°C
60 sec to 75 sec
1.25°C/sec
~50 sec
217°C
260°C +0°C/−5°C
20 sec to 30 sec
3°C/sec max
5 minute max
Rev. A | Page 5 of 16
09568-002
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