Omnidirectional Microphone with
Bottom Port and Analog Output
Data Sheet ADMP405
Rev. B
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 ©2010–2011 Analog Devices, Inc. All rights reserved.
FEATURES
Tiny 3.35 mm × 2.50 mm × 0.88 mm surface-mount package
High SNR of 62 dBA
High sensitivity of −38 dBV
Flat frequency response from 200 Hz to 15 kHz
Low current consumption: <250 μA
Single-ended analog output
High PSRR 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
GENERAL DESCRIPTION
The ADMP405 is a high quality, high performance, low power,
analog output, bottom-ported omnidirectional MEMS
microphone. The ADMP405 consists of a MEMS microphone
element, an impedance converter, and an output amplifier. The
ADMP405 sensitivity specification makes it an excellent choice
for both near field and far field applications. The ADMP405 has
a high SNR and flat wideband frequency response, resulting in
natural sound with high intelligibility. The specially designed
low frequency cutoff reduces wind noise. Low current
consumption enables long battery life for portable applications.
A built-in particle filter provides high reliability. The ADMP405
complies with the TIA-920 Telecommunications Telephone
Terminal Equipment Transmission Requirements for Wideband
Digital Wireline Telephones standard.
The ADMP405 is available in an ultraminiature 3.35 mm ×
2.50 mm × 0.88 mm surface-mount package. It is reflow solder
compatible with no sensitivity degradation. The ADMP405 is
halide free.
FUNCTIONAL BLOCK DIAGRAM
ADMP405
POWER
OUTPUT
VDD
GND
OUTPUT
AMPLIFIER
09027-001
Figure 1.
OBSOLETE
ADMP405 Data Sheet
Rev. B | Page 2 of 12
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications ....................................................................................... 1
General Description ......................................................................... 1
Functional Block Diagram .............................................................. 1
Revision History ............................................................................... 2
Specifications ..................................................................................... 3
Absolute Maximum Ratings ............................................................ 4
ESD Caution .................................................................................. 4
Pin Configuration and Function Descriptions ............................. 5
Typical Performance Characteristics ............................................. 6
Applications Information ................................................................ 7
Connecting to Analog Devices, Inc., Audio Codecs ................7
Supporting Documents ................................................................7
PCB Land Pattern Layout .................................................................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
9/11—Rev. A to Rev. B
Changes to Figure 1 .......................................................................... 1
Changes to Supply Voltage Parameter, Table 1 ............................. 3
Changes to Table 3 ............................................................................ 4
Added Connecting to Analog Devices, Inc., Audio Codecs
Section and Supporting Documents Section ................................ 7
Changes to Pick and Place Equipment Section
(20 kg to 10 kg) .................................................................................. 9
Added LGA_CAV Tape and Reel Outline Dimensions,
Figure 12 .......................................................................................... 11
2/11—Rev. 0 to Rev. A
Changes to Applications Section and
General Description Section ........................................................ 1
Change to Table 1 .............................................................................. 3
Changes to Table 2 ............................................................................. 4
7/10—Revision 0: Initial Version
OBSOLETE
Data Sheet ADMP405
Rev. B | 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 −41 −38 −35 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 200 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 Ratio PSRR 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 IS 250 μA
OUTPUT CHARACTERISTICS
Output Impedance ZOUT 200 Ω
Output DC Offset 0.8 V
Output Current Limit 90 μA
1 See and . Figure 4 Figure 6
OBSOLETE
ADMP405 Data Sheet
Rev. B | 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 +70°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
t
P
t
L
t
25°C
TO PEAK
t
S
PREHEAT
CRIT ICAL Z O NE
T
L
TO T
P
TEMPERATURE
TIME
RAMP-DOWN
RAMP-UP
T
SMIN
T
SMAX
T
P
T
L
09027-002
Figure 2. Recommended Soldering Profile Limits
Table 3. Recommended Soldering Profile Limits
Profile Feature Sn63/Pb37 Pb Free
Average Ramp Rate (TL to TP) 1.25°C/sec max 1.25°C/sec max
Preheat
Minimum Temperature (TSMIN) 100°C 150°C
Maximum Temperature (TSMAX) 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 max 3°C/sec max
Time 25°C (t25°C) to Peak Temperature 5 minute max 5 minute max
OBSOLETE
Data Sheet ADMP405
Rev. B | Page 5 of 12
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
GND
OUTPUT
TOP VIEW
(TERMINAL SIDE DOWN)
Not to Scale
ADMP405
1
V
DD
3
2
09027-003
Figure 3. Pin Configuration
Table 4. Pin Function Descriptions
Pin No. Mnemonic Description
1 OUTPUT Analog Output Signal.
2 GND Ground.
3 VDD Power Supply.
OBSOLETE
ADMP405 Data Sheet
Rev. B | Page 6 of 12
TYPICAL PERFORMANCE CHARACTERISTICS
–10
–8
–6
–4
–2
0
2
4
6
8
10
100 10k1k
FRE Q UE NCY (Hz)
SENSITIVI T Y ( d B)
09027-004
Figure 4. Frequency Response Mask
0
–80
100 10k
FR E QUE NC Y (Hz)
PSRR (d B)
1k
–10
–20
–30
–40
–50
–60
–70
09027-005
Figure 5. Typical Power Supply Rejection Ratio vs. Frequency
10
–20
100
FR E QUENCY (Hz)
(dB)
1k 10k
0
–10
09027-006
Figure 6. Typical Frequency Response (Measured)
OBSOLETE
Data Sheet ADMP405
Rev. B | Page 7 of 12
APPLICATIONS INFORMATION
CONNECTING TO ANALOG DEVICES, INC., AUDIO
CODECS
The ADMP405 output can be connected to a dedicated codec
microphone input (see Figure 7) or to a high input impedance
gain stage (see Figure 8). A 0.1 μF ceramic capacitor placed close
to the ADMP405 supply pin is used for testing and is recom-
mended to adequately decouple the microphone from noise on
the power supply. A dc-blocking capacitor is required at the
output of the microphone.
0
9027-020
ADAU1761
OR
ADAU1361
ADMP405
V
DD
GND
OUTPUT LINN
LINP
MICBIAS
CM
2.2µF
MINIMUM
0.1µF
Figure 7. ADMP405 Connected to the Analog Devices ADAU1761 or
ADAU1361 Codec
09027-021
GAIN = (R1 + R2)/R1
ADMP405
V
DD
GND
OUTPUT
1µF
MINIMUM
0.1µF
V
OUT
V
REF
V
REF
OP177
10kΩ
R1 R2
Figure 8. ADMP405 Connected to the OP177 Op Amp
SUPPORTING DOCUMENTS
Evaluation Board User Guide
UG-143, EVAL-ADMP405Z-FLEX: Bottom-Ported Analog
Output MEMS Microphone Evaluation Board
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
OBSOLETE
ADMP405 Data Sheet
Rev. B | Page 8 of 12
PCB LAND PATTERN LAYOUT
The recommended PCB land pattern for the ADMP405 should
be laid out to a 1:1 ratio to the solder pads on the microphone
package, as shown in Figure 9. Care should be taken to avoid
applying solder paste to the sound hole in the PCB. A suggested
solder paste stencil pattern layout is shown in Figure 10. 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.
Ø1.55
Ø0.95
1.52
0.90
1.90
1.22
0.68
0.61
0.61
09027-007
Figure 9. PCB Land Pattern Layout
1.22
2×0.8 × 0.6
0.2 × 45
TYP 1.52mm
1.55/ 1 . 05 DI A.
0.225 CUT W IDTH ( 2×)
0
9027-008
Figure 10. Suggested Solder Paste Stencil Pattern Layout
OBSOLETE
Data Sheet ADMP405
Rev. B | 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 of 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 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
ADMP405 Data Sheet
Rev. B | 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
Temperature Humidity Bias (THB) +65°C/85% relative humidity (RH), 500 hours, powered
Temperature Cycle −40°C/+125°C, one cycle per hour, 100 cycles
High Temperature Storage +150°C, 500 hours
Low Temperature Storage −40°C, 500 hours
Component Charge Device Model (CDM) ESD All pins, 0.5 kV
Component Human Body Model (HBM) ESD All pins, 1.5 kV
Component Machine Model (MM) ESD All pins, 0.2 kV
OBSOLETE
Data Sheet ADMP405
Rev. B | Page 11 of 12
OUTLINE DIMENSIONS
2.575
2.500
2.425
3.425
3.350
3.275
06-16-2010-A
TOP VIEW
SIDE VIEW
REFERENCE
CORNER
0.98
0.88
0.78
0.21 REF
2.21
REF
3.06 REF
0.65 REF
BOTTOM VIEW
1.08
0.95 DIA.
0.25 NOM
0.20 MIN DIA.
THRU HOLE
(SOUND PORT)
1.22 BSC
1.25
0.54
REF
0.64 REF
1.56 DIA.
1.52
0.75 REF
0.30
BSC
1
3
2
0.90×0.68
(PINS1,3)
0.20TYP
×45°
0.30 BSC
PIN1
Figure 11. 3-Terminal Chip Array Small Outline No Lead Cavity [LGA_CAV]
3.35 mm × 2.50 mm Body
(CE-3-2)
Dimensions shown in millimeters
NOTES
1. 10 SPROCKET HOLE PITCH CUMULATIVE TOLERANCE ±0.2.
2. CAMBER IN COMPLIANCE WITH EIA 481.
3. POCKET POSITION RELATIVE TO SPROCKET HOLE MEASURED
AS TRUE POSITION OF POCKET, NOT POCKET HOLE.
4. A
O
AND B
O
ARE CALCULATED ON A PLANE AT A DISTANCE “R”
ABOVE THE BOTTOM OF THE POCKET.
K
O
2.90
R 0.2 MAX
B
O
3.85
A
O
1.25 R 0.3 TYP 0.76 MIN
01.5 +0.1/0.0
12.0 +0.3/–0.1
5.5 ±0.05
(SEE NOTE 3)
1.13
POCKET HOLE
OFFSET
A
A
1.75 ±0.1
4.0
2.0 ± 0.05 (SEE NOTE 3)
0.25 ±0.05 4.0 (SEE NOTE 1)
09027-009
Figure 12. LGA_CAV Tape and Reel Outline Dimensions
Dimensions shown in millimeters
ORDERING GUIDE
Model1 Temperature Range Package Description Package Option2 Ordering Quantity
ADMP405ACEZ-RL −40°C to +70°C 3-Terminal LGA_CAV, 13” Tape and Reel CE-3-2 10,000
ADMP405ACEZ-RL7 −40°C to +70°C 3-Terminal LGA_CAV, 7” Tape and Reel CE-3-2 1,000
EVAL-ADMP405Z-FLEX Evaluation Board
1 Z = RoHS Compliant Part.
2 This package option is halide free.
OBSOLETE
