Omnidirectional Microphone with
Bottom Port and Analog Output
Data Sheet
ADMP401
Rev. E
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.
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Tel: 781.329.4700 www.analog.com
Fax: 781.461.3113 ©2010–2012 Analog Devices, Inc. All rights reserved.
FEATURES
4.72 mm × 3.76 mm × 1.0 mm surface-mount package
High SNR of 62 dBA
Sensitivity of −42 dBV
Flat frequency response from 100 Hz to 15 kHz
Low current consumption of <250 μA
Single-ended analog output
High PSR of 70 dB
Compatible with Sn/Pb and Pb-free solder processes
RoHS/WEEE compliant
APPLICATIONS
Smartphones and feature phones
Teleconferencing systems
Digital video cameras
Bluetooth headsets
Video phones
Tablets
FUNCTIONAL BLOCK DIAGRAM
OUTPUT
AMPLIFIER
ADMP401
POWER
07712-001
VDD GND
OUTPUT
Figure 1.
GENERAL DESCRIPTION
The ADMP4011 is a high quality, high performance, low power,
analog output, bottom-ported omnidirectional MEMS
microphone. The ADMP401 consists of a MEMS microphone
element, an impedance converter, and an output amplifier. The
ADMP401 sensitivity specification makes it an excellent choice
for both near field and far field applications. The ADMP401 has
a high SNR and flat wideband frequency response, resulting in
natural sound with high intelligibility. Low current consumption
enables long battery life for portable applications. The ADMP401
complies with the TIA-920 standard, Telecommunications
Telephone Terminal Equipment Transmission Requirements for
Wideband Digital Wireline Telephones.
The ADMP401 is available in a thin, 4.72 mm × 3.76 mm ×
1.0 mm surface-mount package. It is reflow solder compatible
with no sensitivity degradation. The ADMP401 is halide free.
1 Protected by U.S. Patents 7,449,356; 7,825,484; 7,885,423; 7,961,897. Other patents are pending.
OBSOLETE
ADMP401 Data Sheet
Rev. E | Page 2 of 12
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications ....................................................................................... 1
Functional Block Diagram .............................................................. 1
General Description ......................................................................... 1
Revision History ............................................................................... 2
Specifications ..................................................................................... 3
Absolute Maximum Ratings ............................................................ 4
ESD Caution .................................................................................. 4
Pin Configuration and Function Descriptions ............................. 5
Printed Circuit Board (PCB) Land Pattern Layout ...................... 6
Typical Performance Characteristics ............................................. 7
Applications Information ................................................................ 8
Connecting the ADMP401 to a Codec ......................................8
Connecting the ADMP401 to an Op Amp Gain Stage ............8
Supporting Documents ................................................................8
Handling Instructions .......................................................................9
Pick-and-Place Equipment ..........................................................9
Reflow Solder .................................................................................9
Board Wash ....................................................................................9
Reliability Specifications ................................................................ 10
Outline Dimensions ....................................................................... 11
Ordering Guide .......................................................................... 11
REVISION HISTORY
7/12—Rev. D to Rev. E
Changes to Features Section, General Description Section, and
Page 1 Layout .................................................................................... 1
Add Note 1 ......................................................................................... 1
Changes to Frequency Response Parameter, Table 1 and Powers
Supply Rejection Parameter, Table 1 .............................................. 3
Changes to Temperature Range Parameter, Table 2 ..................... 4
Changes to Figure 6, Figure 7, and Figure 8.................................. 7
Changes to Applications Information Section and Figure 10..... 8
Added Supporting Documents Section, Application Notes
Section, Circuit Notes Section, and Evaluation Board User
Guides Section .................................................................................. 8
Changes to THB Description Column, Table 5 and Temperature
Cycle Column, Table 5 ................................................................... 10
Changes to Ordering Guide .......................................................... 11
1/12—Rev. C to Rev. D
Updated Outline Dimensions ....................................................... 11
Changes to Figure 12 ...................................................................... 11
Added Figure 13 .............................................................................. 11
Change to Ordering Guide ............................................................ 11
8/11—Rev. B to Rev. C
Changes to Figure 1 ........................................................................... 1
Changes to Table 3 ............................................................................. 4
Removed Terminal Side Down from Figure 3 ............................... 5
Changes to Bullet 2 in Pick-and-Place Equipment Section ......... 9
Changes to Ordering Guide .......................................................... 11
12/10—Rev. A to Rev. B
Changes to Applications and General Description Sections ....... 1
Changes to Table 1 ............................................................................. 3
8/10—Rev. 0 to Rev. A
Changes to Frequency Response Parameter, Table 1 .................... 3
Changes to Supply Voltage Parameter, Table 2 .............................. 4
Changes to Applications Information Section, Figure 9, and
Figure 10 ............................................................................................. 8
Updated Outline Dimensions ....................................................... 11
4/10—Revision 0: Initial Version
OBSOLETE
Data Sheet ADMP401
Rev. E | Page 3 of 12
SPECIFICATIONS
TA = 25°C, VDD = 1.8 V, unless otherwise noted. All minimum and maximum specifications are guaranteed. Typical specifications are not
guaranteed.
Table 1.
Parameter Symbol Test Conditions/Comments Min Typ Max Unit
PERFORMANCE
Directionality Omni
Sensitivity 1 kHz, 94 dB SPL −45 −42 −39 dBV
Signal-to-Noise Ratio SNR 62 dBA
Equivalent Input Noise EIN 32 dBA SPL
Dynamic Range
Derived from EIN and maximum acoustic input
88
dB
Frequency Response1 Low frequency, −3 dB point 60 Hz
High frequency, −3 dB point 15 kHz
Deviation limits from flat response within pass band −3/+2 dB
Total Harmonic Distortion THD 105 dB SPL 3 %
Power Supply Rejection PSR 217 Hz, 100 mV p-p square wave superimposed on VDD = 1.8 V 70 dB
Maximum Acoustic Input Peak 120 dB SPL
POWER SUPPLY
Supply Voltage VDD 1.5 3.3 V
Supply Current
I
S
250
µA
OUTPUT CHARACTERISTICS
Output Impedance ZOUT 200 Ω
Output DC Offset 0.8 V
Output Current Limit 90 µA
1 See Figure 6 and Figure 7.
OBSOLETE
ADMP401 Data Sheet
Rev. E | Page 4 of 12
ABSOLUTE MAXIMUM RATINGS
Table 2.
Parameter Rating
Supply Voltage −0.3 V to +3.6 V
Sound Pressure Level (SPL)
160 dB
Mechanical Shock 10,000 g
Vibration Per MIL-STD-883 Method 2007,
Test Condition B
Temperature Range −40°C to +85°C
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
07712-002
t
P
t
L
t
25°C TO PEAK
t
S
PREHEAT
CRITICAL ZONE
T
L
TO T
P
TEMPERATURE
TIME
RAMP-DOWN
RAMP-UP
T
SMIN
T
SMAX
T
P
T
L
Figure 2. Recommended Soldering Profile Limits
Table 3. Recommended Soldering Profile Limits
Profile Feature Sn-Pb Pb Free
Average Ramp Rate (TL to TP) 1.25°C/sec maximum 1.25°C/sec maximum
Preheat
Minimum Temperature (TSMIN) 100°C 100°C
Maximum Temperature (T
SMAX
)
150°C
200°C
Time (TSMIN to TSMAX), tS 60 sec to 75 sec 60 sec to 75 sec
Ramp-Up Rate (TSMAX to TL) 1.25°C/sec 1.25°C/sec
Time Maintained Above Liquidous (tL) 45 sec to 75 sec ~50 sec
Liquidous Temperature (TL) 183°C 217°C
Peak Temperature (TP) 215°C +3°C/−3°C 245°C +0°C/−5°C
Time Within 5°C of Actual Peak Temperature (tP) 20 sec to 30 sec 20 sec to 30 sec
Ramp-Down Rate 3°C/sec maximum 3°C/sec maximum
Time 25°C (t25°C) to Peak Temperature 5 min maximum 5 min maximum
OBSOLETE
Data Sheet ADMP401
Rev. E | Page 5 of 12
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
07712-003
BOTTOM VIEW
Not t o Scal e
GND
OUTPUT
GND
V
DD
GND
GND
3
12
4
5
6
Figure 3. Pin Configuration (Bottom View)
Table 4. Pin Function Descriptions
Pin No. Mnemonic Description
1 OUTPUT Analog Output Signal
2 GND Ground
3 GND Ground
4
GND
Ground
5 VDD Power Supply
6 GND Ground
OBSOLETE
ADMP401 Data Sheet
Rev. E | Page 6 of 12
PRINTED CIRCUIT BOARD (PCB) LAND PATTERN LAYOUT
The recommended PCB land pattern for the ADMP401 should
have a 1:1 ratio to the solder pads on the microphone package,
as shown in Figure 4. Take care to avoid applying solder paste to
the sound hole in the PCB.
A suggested solder paste stencil pattern layout is shown in
Figure 5. The diameter of the sound hole in the PCB should be
larger than the diameter of the sound port of the microphone.
A minimum diameter of 0.5 mm is recommended.
2.62
ø1.10
ø1.68
ø0.70 (2×)
ø0.90 (3×)
2.40
1.20
2.54
0.79
1.27
07712-004
Figure 4. PCB Land Pattern Layout (Dimensions Shown in mm)
1.27mm
1.2mm
2.54mm
2.62mm
3.41mm
2.4mm
0.85mm DIA. ( 3× ) 1.8mm/1. 3mm DIA. 0.2032 CUT WI DTH (4× ) 0.649mm DIA. ( 2× )
07712-005
Figure 5. Suggested Solder Paste Stencil Pattern Layout
OBSOLETE
Data Sheet ADMP401
Rev. E | Page 7 of 12
TYPICAL PERFORMANCE CHARACTERISTICS
10
–10
–8
–6
–4
–2
0
2
4
6
8
50 100 10k
FREQUENCY (Hz)
SENSITIVITY (dB)
1k
07712-006
Figure 6. Frequency Response Mask
10
–20
–10
0
10 100 10k
FREQUENCY (Hz)
AMPLITUDE ( dB)
1k
07712-007
Figure 7. Typical Frequency Response (Measured)
0
–80
100 10k
FRE QUENCY ( Hz )
PSR (dB)
1k
–10
–20
–30
–40
–50
–60
–70
07712-008
Figure 8. Typical Power Supply Rejection vs. Frequency
OBSOLETE
ADMP401 Data Sheet
Rev. E | Page 8 of 12
APPLICATIONS INFORMATION
The ADMP401 output can be connected to a dedicated codec
microphone input (see Figure 9) or to a high input impedance
gain stage (see Figure 10). A 0.1 µF ceramic capacitor placed
close to the ADMP401 supply pin is used for testing and is
recommended to adequately decouple the microphone from
noise on the power supply. A dc-blocking capacitor is required
at the output of the microphone. This capacitor creates a high-
pass filter with a corner frequency at
fC = 1/(2π × C × R)
where R is the input impedance of the codec.
A minimum value of 2.2 µF is recommended in Figure 9
because the input impedance of the ADAU1361/ADAU1761
can be as low as 2 kΩ at its highest PGA gain setting, which
results in a high-pass filter corner frequency at about 37 Hz.
Figure 10 shows the ADMP401 connected to the ADA4897-1
op amp configured as a noninverting preamplifier.
CONNECTING THE ADMP401 TO A CODEC
07712-009
LINN
LINP
MICBIAS
ADAU1761
OR
ADAU1361
2.2µF
MINIMUM
VDD
GND
ADMP401
OUTPUT
CM
0.1µF
Figure 9. ADMP401 Connected to the Analog Devices ADAU1761 or
ADAU1361 Codec
CONNECTING THE ADMP401 TO AN OP AMP
GAIN STAGE
1µF
MINIMUM
10kΩ
R2
R1
VREF
ADA4897-1
07712-010
VDD
GAIN = (R1 + R2)/R1
GND
ADMP401
OUTPUT
0.1µF
VO
VREF
Figure 10. ADMP401 Connected to the ADA4897-1 Op Amp
SUPPORTING DOCUMENTS
Application Notes
AN-1003, Recommendations for Mounting and Connecting
Analog Devices, Inc., Bottom-Ported MEMS Microphones
AN-1068, Reflow Soldering of the MEMS Microphone
AN-1112, Microphone Specifications Explained
AN-1124, Recommendations for Sealing Analog Devices, Inc.,
Bottom-Port MEMS Microphones from Dust and Liquid
Ingress
AN-1140, Microphone Array Beamforming
Circuit Notes
CN-0207, High Performance Analog MEMS Microphone’s Simple
Interface to SigmaDSP Audio Codec
CN-0262, Low Noise Analog MEMS Microphone and Preamp
with Compression and Noise Gating
Evaluation Board User Guides
UG-126, EVAL-ADMP401Z: Bottom-Ported Analog Output MEMS
Microphone Evaluation Board
UG-278, EVAL -ADMP401Z-FLEX: Bottom-Ported Analog
Output MEMS Microphone Evaluation Board
OBSOLETE
Data Sheet ADMP401
Rev. E | Page 9 of 12
HANDLING INSTRUCTIONS
PICK-AND-PLACE EQUIPMENT
The MEMS microphone can be handled using standard pick-
and-place and chip shooting equipment. Care should be taken
to avoid damage to the MEMS microphone structure as follows:
• Use a standard pickup tool to handle the microphone.
Because the microphone hole is on the bottom of the
package, the pickup tool can make contact with any part
of the lid surface.
• Use care during pick-and-place to ensure that no high
shock events above 10 kg are experienced because such
events may cause damage to the microphone.
• Do not pick up the microphone with a vacuum tool that
makes contact with the bottom side of the microphone.
• Do not pull air out or blow air into the microphone port.
• Do not use excessive force to place the microphone on
the PCB.
REFLOW SOLDER
For best results, the soldering profile should be in accordance
with the recommendations of the manufacturer of the solder
paste that is used to attach the MEMS microphone to the PCB.
It is recommended that the solder reflow profile not exceed the
limit conditions specified in Figure 2 and Table 3.
BOARD WASH
When washing the PCB, ensure that water does not make
contact with the microphone port. Blow-off procedures and
ultrasonic cleaning must not be used.
OBSOLETE
ADMP401 Data Sheet
Rev. E | Page 10 of 12
RELIABILITY SPECIFICATIONS
The microphone sensitivity after stress must deviate by no more than ±3 dB from the initial value.
Table 5.
Stress Test Description
Low Temperature Operating Life −40°C, 500 hours, powered
High Temperature Operating Life +125°C, 500 hours, powered
THB +85°C/85% relative humidity, 500 hours, powered
Temperature Cycle −40°C/+125°C, one cycle per hour, 1000 cycles
High Temperature Storage +150°C, 500 hours
Low Temperature Storage −40°C, 500 hours
Component CDM ESD
All pins, 0.5 kV
Component HBM ESD All pins, 1.5 kV
Component MM ESD All pins, 0.2 kV
OBSOLETE
Data Sheet ADMP401
Rev. E | Page 11 of 12
OUTLINE DIMENSIONS
3.86
3.76
3.66
4.82
4.72
4.62
BOTTOM VIEW
TOP VI EW
SIDE VIEW
0.90 DIA.
(PINS 1, 5, 6)
1
3
2
4
5
6
2.62 BS C
3.30 RE F
1.10 DIA.
1.68 DIA.
0.25 DIA.
(T HRU HOLE )
0.79 BS C
2.54
BSC
1.27 BS C
1.10
1.00
0.90
0.24 RE F
0.73 RE F
1.20 BS C
2.40 BS C
0.68 RE F 0.61 RE F
0.70 DIA.
(PINS 2, 4)
12-12-2011-C
3.14
REF
4.10 RE F
REFERENCE
CORNER
PI N 1
Figure 11. 6-Terminal Chip Array Small Outline No Lead Cavity [LGA_CAV]
4.72 mm × 3.76 mm Body
(CE-6-1)
Dimensions shown in millimeters
PI N 1
DIRECTION OF FEED
07712-011
Figure 12. Microphone Orientation in Tape Until Date Code 1213
07712-012
PI N 1
DIRECTION OF FEED
Figure 13. Microphone Orientation in Tape Starting with Date Code 1213
ORDERING GUIDE
Model
1
Temperature Range
Package Description
Package Option
2
Ordering Quantity
ADMP401ACEZ-RL −40°C to +85°C 6-Terminal LGA_CAV, 13” Tape and Reel CE-6-1 4,500
ADMP401ACEZ-RL7
−40°C to +85°C
6-Terminal LGA_CAV, 7” Tape and Reel
CE-6-1
1,000
EVAL-ADMP401Z Evaluation Board
EVAL-ADMP401Z-FLEX Evaluation Board
1 Z = RoHS Compliant Part.
2 The CE-6-1 package option is halide free.
OBSOLETE
