Omnidirectional Microphone with

Bottom Port and Analog Output

Data Sheet ADMP401
FEATURES FUNCTIONAL BLOCK DIAGRAM
4.72 mm × 3.76 mm × 1.0 mm surface-mount package
High SNR of 62 dBA
Sensitivity of −42 dBV OUTPUT
OUTPUT
Flat frequency response from 100 Hz to 15 kHz AMPLIFIER

Low current consumption of <250 μA

Single-ended analog output
POWER
High PSR of 70 dB ADMP401

07712-001
Compatible with Sn/Pb and Pb-free solder processes

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VDD GND
RoHS/WEEE compliant
Figure 1.

APPLICATIONS
Smartphones and feature phones
Teleconferencing systems
Digital video cameras
Bluetooth headsets
Video phones
Tablets
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GENERAL DESCRIPTION
The ADMP4011 is a high quality, high performance, low power, enables long battery life for portable applications. The ADMP401
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analog output, bottom-ported omnidirectional MEMS complies with the TIA-920 standard, Telecommunications
microphone. The ADMP401 consists of a MEMS microphone Telephone Terminal Equipment Transmission Requirements for
element, an impedance converter, and an output amplifier. The Wideband Digital Wireline Telephones.
ADMP401 sensitivity specification makes it an excellent choice The ADMP401 is available in a thin, 4.72 mm × 3.76 mm ×
for both near field and far field applications. The ADMP401 has 1.0 mm surface-mount package. It is reflow solder compatible
a high SNR and flat wideband frequency response, resulting in with no sensitivity degradation. The ADMP401 is halide free.
natural sound with high intelligibility. Low current consumption
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Protected by U.S. Patents 7,449,356; 7,825,484; 7,885,423; 7,961,897. Other patents are pending.

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 One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Tel: 781.329.4700 www.analog.com
Trademarks and registered trademarks are the property of their respective owners. Fax: 781.461.3113 ©2010–2012 Analog Devices, Inc. All rights reserved.
ADMP401 Data Sheet

TABLE OF CONTENTS
Features .............................................................................................. 1 Connecting the ADMP401 to a Codec ......................................8
Applications ....................................................................................... 1 Connecting the ADMP401 to an Op Amp Gain Stage ............8
Functional Block Diagram .............................................................. 1 Supporting Documents ................................................................8
General Description ......................................................................... 1 Handling Instructions .......................................................................9
Revision History ............................................................................... 2 Pick-and-Place Equipment ..........................................................9
Specifications..................................................................................... 3 Reflow Solder .................................................................................9
Absolute Maximum Ratings ............................................................ 4 Board Wash ....................................................................................9
ESD Caution .................................................................................. 4 Reliability Specifications ................................................................ 10
Pin Configuration and Function Descriptions ............................. 5 Outline Dimensions ....................................................................... 11

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Printed Circuit Board (PCB) Land Pattern Layout ...................... 6 Ordering Guide .......................................................................... 11
Typical Performance Characteristics ............................................. 7
Applications Information ................................................................ 8

REVISION HISTORY
7/12—Rev. D to Rev. E
Changes to Features Section, General Description Section, and
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Page 1 Layout .................................................................................... 1
Add Note 1......................................................................................... 1
Changes to Frequency Response Parameter, Table 1 and Powers
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
Supply Rejection Parameter, Table 1 .............................................. 3 Changes to Ordering Guide .......................................................... 11
Changes to Temperature Range Parameter, Table 2..................... 4
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Changes to Figure 6, Figure 7, and Figure 8.................................. 7 12/10—Rev. A to Rev. B
Changes to Applications Information Section and Figure 10..... 8 Changes to Applications and General Description Sections .......1
Added Supporting Documents Section, Application Notes Changes to Table 1.............................................................................3
Section, Circuit Notes Section, and Evaluation Board User
Guides Section .................................................................................. 8 8/10—Rev. 0 to Rev. A
Changes to THB Description Column, Table 5 and Temperature Changes to Frequency Response Parameter, Table 1 ....................3
Cycle Column, Table 5 ................................................................... 10 Changes to Supply Voltage Parameter, Table 2 ..............................4
Changes to Ordering Guide .......................................................... 11 Changes to Applications Information Section, Figure 9, and
B

Figure 10 .............................................................................................8
1/12—Rev. C to Rev. D Updated Outline Dimensions ....................................................... 11
Updated Outline Dimensions ....................................................... 11
Changes to Figure 12 ...................................................................... 11 4/10—Revision 0: Initial Version
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Added Figure 13.............................................................................. 11

Change to Ordering Guide ............................................................ 11

Rev. E | Page 2 of 12
Data Sheet ADMP401

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 Response 1 Low frequency, −3 dB point 60 Hz

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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
OUTPUT CHARACTERISTICS
Output Impedance
Output DC Offset
IS

ZOUT
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0.8
250 µA

Ω
V
Output Current Limit 90 µA
1
See Figure 6 and Figure 7.
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Rev. E | Page 3 of 12
ADMP401 Data Sheet

ABSOLUTE MAXIMUM RATINGS

Table 2. ESD CAUTION
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

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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.

CRITICAL ZONE
tP TL TO TP
TP

TL
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TEMPERATURE

TSMAX tL

TSMIN

tS
PREHEAT RAMP-DOWN
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07712-002

t25°C TO PEAK
TIME

Figure 2. Recommended Soldering Profile Limits

Table 3. Recommended Soldering Profile Limits

Profile Feature Sn-Pb Pb Free
B

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 (TSMAX) 150°C 200°C
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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

Rev. E | Page 4 of 12
Data Sheet ADMP401

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

OUTPUT GND
1 2
GND
GND 3

VDD

5 4

GND

07712-003
BOTTOM VIEW
Not to Scale

Figure 3. Pin Configuration (Bottom View)

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Table 4. Pin Function Descriptions
Pin No. Mnemonic Description
1 OUTPUT Analog Output Signal
2 GND Ground
3 GND Ground
4
5
6
GND
VDD
GND
Ground LE
Power Supply
Ground
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Rev. E | Page 5 of 12
ADMP401 Data Sheet
PRINTED CIRCUIT BOARD (PCB) LAND PATTERN LAYOUT
The recommended PCB land pattern for the ADMP401 should A suggested solder paste stencil pattern layout is shown in
have a 1:1 ratio to the solder pads on the microphone package, Figure 5. The diameter of the sound hole in the PCB should be
as shown in Figure 4. Take care to avoid applying solder paste to larger than the diameter of the sound port of the microphone.
the sound hole in the PCB. A minimum diameter of 0.5 mm is recommended.

2.62
ø0.90 (3×)

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ø1.10

ø1.68
2.40 2.54

1.20 1.27
ø0.70 (2×)

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07712-004
0.79

Figure 4. PCB Land Pattern Layout (Dimensions Shown in mm)

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1.8mm/1.3mm DIA. 0.2032 CUT WIDTH (4×) 0.649mm DIA. (2×)
0.85mm DIA. (3×)

2.4mm 2.54mm
B

1.2mm 1.27mm
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2.62mm
07712-005

3.41mm

Figure 5. Suggested Solder Paste Stencil Pattern Layout

Rev. E | Page 6 of 12
Data Sheet ADMP401

TYPICAL PERFORMANCE CHARACTERISTICS

10 0

8
–10
6
–20
4
SENSITIVITY (dB)

–30
2

PSR (dB)
0 –40

–2
–50
–4
–60
–6

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–70
–8

–10 –80
07712-006

07712-008
50 100 1k 10k 100 1k 10k
FREQUENCY (Hz) FREQUENCY (Hz)

Figure 6. Frequency Response Mask Figure 8. Typical Power Supply Rejection vs. Frequency

10 LE
0
AMPLITUDE (dB)

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–10

–20
07712-007

10 100 1k 10k
FREQUENCY (Hz)
B

Figure 7. Typical Frequency Response (Measured)

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Rev. E | Page 7 of 12
ADMP401 Data Sheet
APPLICATIONS INFORMATION
The ADMP401 output can be connected to a dedicated codec CONNECTING THE ADMP401 TO AN OP AMP
microphone input (see Figure 9) or to a high input impedance GAIN STAGE
gain stage (see Figure 10). A 0.1 µF ceramic capacitor placed GAIN = (R1 + R2)/R1
close to the ADMP401 supply pin is used for testing and is 0.1µF
R2
R1
recommended to adequately decouple the microphone from VDD VREF
noise on the power supply. A dc-blocking capacitor is required
ADMP401
at the output of the microphone. This capacitor creates a high- 1µF
MINIMUM VO
pass filter with a corner frequency at OUTPUT
ADA4897-1
10kΩ
fC = 1/(2π × C × R) GND

07712-010
VREF
where R is the input impedance of the codec.
A minimum value of 2.2 µF is recommended in Figure 9 Figure 10. ADMP401 Connected to the ADA4897-1 Op Amp

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because the input impedance of the ADAU1361/ADAU1761 SUPPORTING DOCUMENTS
can be as low as 2 kΩ at its highest PGA gain setting, which
Application Notes
results in a high-pass filter corner frequency at about 37 Hz.
Figure 10 shows the ADMP401 connected to the ADA4897-1 AN-1003, Recommendations for Mounting and Connecting
op amp configured as a noninverting preamplifier. Analog Devices, Inc., Bottom-Ported MEMS Microphones

CONNECTING THE ADMP401 TO A CODEC AN-1068, Reflow Soldering of the MEMS Microphone
AN-1112, Microphone Specifications Explained

VDD

ADMP401
0.1µF

2.2µF
MINIMUM
MICBIAS

ADAU1761
OR
ADAU1361
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Bottom-Port MEMS Microphones from Dust and Liquid
Ingress
AN-1140, Microphone Array Beamforming
OUTPUT LINN
Circuit Notes
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GND CN-0207, High Performance Analog MEMS Microphone’s Simple
LINP
Interface to SigmaDSP Audio Codec
07712-009

CM CN-0262, Low Noise Analog MEMS Microphone and Preamp

Figure 9. ADMP401 Connected to the Analog Devices ADAU1761 or
with Compression and Noise Gating
ADAU1361 Codec Evaluation Board User Guides
UG-126, EVAL-ADMP401Z: Bottom-Ported Analog Output MEMS
Microphone Evaluation Board
B

UG-278, EVAL-ADMP401Z-FLEX: Bottom-Ported Analog

Output MEMS Microphone Evaluation Board
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Rev. E | Page 8 of 12
Data Sheet ADMP401

HANDLING INSTRUCTIONS
PICK-AND-PLACE EQUIPMENT REFLOW SOLDER
The MEMS microphone can be handled using standard pick- For best results, the soldering profile should be in accordance
and-place and chip shooting equipment. Care should be taken with the recommendations of the manufacturer of the solder
to avoid damage to the MEMS microphone structure as follows: paste that is used to attach the MEMS microphone to the PCB.
It is recommended that the solder reflow profile not exceed the
• Use a standard pickup tool to handle the microphone.
limit conditions specified in Figure 2 and Table 3.
Because the microphone hole is on the bottom of the
package, the pickup tool can make contact with any part BOARD WASH
of the lid surface. When washing the PCB, ensure that water does not make
• Use care during pick-and-place to ensure that no high contact with the microphone port. Blow-off procedures and
shock events above 10 kg are experienced because such ultrasonic cleaning must not be used.
events may cause damage to the microphone.

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• 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.

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Rev. E | Page 9 of 12
ADMP401 Data Sheet

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

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Component MM ESD All pins, 0.2 kV

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Rev. E | Page 10 of 12
Data Sheet ADMP401

OUTLINE DIMENSIONS
4.82
4.72
4.62 REFERENCE 3.30 REF
4.10 REF CORNER 0.79 BSC
2.62 BSC
PIN 1
0.90 DIA.
(PINS 1, 5, 6)
1 2

3.86 1.68 DIA.

3 2.54
3.76 2.40 BSC 1.10 DIA.
6 BSC
3.66

3.14 1.20 BSC 0.25 DIA. 1.27 BSC

REF (THRU HOLE)
5 4

TOP VIEW 0.68 REF 0.61 REF

BOTTOM VIEW
0.70 DIA.
1.10 (PINS 2, 4)
0.73 REF

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1.00
0.90

12-12-2011-C
SIDE VIEW
0.24 REF

Figure 11. 6-Terminal Chip Array Small Outline No Lead Cavity [LGA_CAV]
4.72 mm × 3.76 mm Body
(CE-6-1)

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DIRECTION OF FEED
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PIN 1
07712-011

Figure 12. Microphone Orientation in Tape Until Date Code 1213

DIRECTION OF FEED
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PIN 1
07712-012
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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.

Rev. E | Page 11 of 12
ADMP401 Data Sheet

NOTES

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©2010–2012 Analog Devices, Inc. All rights reserved. Trademarks and

registered trademarks are the property of their respective owners.
D07712-0-7/12(E)

Rev. E | Page 12 of 12