INMP405
Omnidirectional Microphone with Bottom Port and Analog Output
GENERAL DESCRIPTION
The INMP405* is a high-quality, high-performance, low-power,
analog-output bottom-ported omnidirectional MEMS
microphone. The INMP405 consists of a MEMS microphone
element, an impedance converter, and an output amplifier.
The INMP405 sensitivity specification makes it an excellent
choice for near-field applications. The INMP405 has a
wideband frequency response, resulting in natural sound with
high intelligibility. The specially designed low frequency cutoff
reduces wind noise. Its low current consumption enables long
battery life for portable applications.
The INMP405 complies with the TIA-920 Telecommunications
Telephone Terminal Equipment Transmission Requirements for
Wideband Digital Wireline Telephones standard.
The INMP405 is available in a miniature 3.35 ×
2.50 × 0.88 mm surface-mount package. It is reflow solder
compatible with no sensitivity degradation. The INMP405 is
halide free.
*Protected by U.S. Patents 7,449,356; 7,825,484; 7,885,423; and 7,961,897.
Other patents are pending.
APPLICATIONS
• Mobile Devices
• Teleconferencing Systems
• Headsets
• Security Panels
• Intercom Devices
FEATURES
• 3.35 × 2.50 × 0.88 mm Surface-Mount Package
• SNR of 62 dBA
• Sensitivity of −38 dBV
• Flat Frequency Response from 200 Hz to 15 kHz
• Low Current Consumption: <250 µA
• Single-Ended Analog Output
• High PSR of 70 dB
• Compatible with Sn/Pb and Pb-free Solder Processes
• RoHS/WEEE Compliant
ORDERING INFORMATION
PART
TEMP RANGE
INMP405ACEZ-R0*
−40°C to +85°C
INMP405ACEZ-R7†
−40°C to +85°C
EV_INMP405-FX
—
* – 13” Tape and Reel
† – 7” Tape and reel to be discontinued. Contact sales@invensense.com for
availability.
OUTPUT
AMPLIFIER
INMP405
POWER
VDD
GND
OUTPUT
FUNCTIONAL BLOCK DIAGRAM
InvenSense reserves the right to change the detail
specifications as may be required to permit
improvements in the design of its products.
InvenSense Inc.
1745 Technology Drive, San Jose, CA 95110 U.S.A
+1(408) 988–7339
www.invensense.com
Document Number: DS-INMP405-00
Revision: 1.0.
Rev Date: 02/06/2014
INMP405
TABLE OF CONTENTS
General Description ........................................................................................................................................................ 1
Applications .................................................................................................................................................................... 1
Features .......................................................................................................................................................................... 1
Functional Block Diagram ............................................................................................................................................... 1
Ordering Information ...................................................................................................................................................... 1
Table of Contents ............................................................................................................................................................ 2
Specifications .................................................................................................................................................................. 3
Table 1. Electrical Characteristics ................................................................................................................................... 3
Absolute Maximum Ratings ............................................................................................................................................ 4
Table 2. Absolute Maximum Ratings .............................................................................................................................. 4
ESD Caution ..................................................................................................................................................................... 4
Soldering Profile .............................................................................................................................................................. 5
Table 3. Recommended Soldering Profile* ..................................................................................................................... 5
Pin Configurations And Function Descriptions ............................................................................................................... 6
Table 4. Pin Function Descriptions .................................................................................................................................. 6
Typical Performance Characteristics ............................................................................................................................... 7
Applications Information ................................................................................................................................................ 8
Connecting To Audio Codecs .......................................................................................................................................... 8
Supporting Documents ................................................................................................................................................... 9
Evaluation Board User Guide .......................................................................................................................................... 9
Application Note (product specific) ................................................................................................................................ 9
Application Notes (general) ............................................................................................................................................ 9
PCB Design And Land Pattern Layout ........................................................................................................................... 10
Handling Instructions .................................................................................................................................................... 11
Pick And Place Equipment ............................................................................................................................................ 11
Reflow Solder ................................................................................................................................................................ 11
Board Wash ................................................................................................................................................................... 11
Outline Dimensions ....................................................................................................................................................... 12
Ordering Guide ............................................................................................................................................................. 12
Revision History ............................................................................................................................................................ 12
Compliance Declaration Disclaimer: ............................................................................................................................. 13
Environmental Declaration Disclaimer: ........................................................................................................................ 13
Page 2 of 13
Document Number: DS-INMP405-00
Revision: 1.0.
Rev Date: 02/06/2014
INMP405
SPECIFICATIONS
TABLE 1. ELECTRICAL CHARACTERISTICS
(TA = −40 to 85°C, VDD = 1.5 to 3.3 V, unless otherwise noted. All minimum and maximum specifications are guaranteed across
temperature and voltage, and are specified in Table 1, unless otherwise noted. Typical specifications are not guaranteed.)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
NOTES
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 Response
Low frequency −3 dB point
200
Hz
1
High frequency −3 dB point
15
kHz
Total Harmonic Distortion (THD)
105 dB SPL
3
%
Power-Supply Rejection (PSR)
217 Hz, 100 mVp-p square
wave superimposed on VDD
= 1.8 V
−70 dBV
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
Note 1: See Figures 3 and 5.
Page 3 of 13
Document Number: DS-INMP405-00
Revision: 1.0.
Rev Date: 02/06/2014
INMP405
ABSOLUTE MAXIMUM RATINGS
Stress above those listed as Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only
and functional operation of the device at these conditions is not implied. Exposure to the absolute maximum ratings conditions for
extended periods may affect device reliability.
TABLE 2. ABSOLUTE MAXIMUM RATINGS
PARAMETER
RATING
Supply Voltage (VDD)
−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
ESD CAUTION
ESD (electrostatic discharge) sensitive device.
Charged devices and circuit boards can
discharge without detection. Although this
product features patented or proprietary
protection circuitry, damage may occur on
devices subjected to high energy ESD.
Therefore proper ESD precautions should be
taken to avoid performance degradation or
loss of functionality.
Page 4 of 13
Document Number: DS-INMP405-00
Revision: 1.0.
Rev Date: 02/06/2014
INMP405
SOLDERING PROFILE
Figure 1. Recommended Soldering Profile Limits
TABLE 3. RECOMMENDED SOLDERING PROFILE*
PROFILE FEATURE
Sn63/Pb37
Pb-Free
Average Ramp Rate (T
L
to T
P
)
1.25°C/sec max
1.25°C/sec max
Preheat
Minimum Temperature
(TSMIN)
100°C 100°C
Minimum Temperature
(TSMIN)
150°C 200°C
Time (TSMIN to TSMAX), tS
60 sec to 75 sec
60 sec to 75 sec
Ramp-Up Rate (T
SMAX
to T
L
) 1.25°C/sec 1.25°C/sec
Time Maintained Above Liquidous (t
L
) 45 sec to 75 sec ~50 sec
Liquidous Temperature (TL) 183°C 217°C
Peak Temperature (T
P
)
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 (t
25°C
) to Peak
Temperature
5 min max 5 min max
*The reflow profile in Table 3 is recommended for board manufacturing with InvenSense MEMS microphones. All
microphones are also compatible with the J-STD-020 profile.
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
Page 5 of 13
Document Number: DS-INMP405-00
Revision: 1.0.
Rev Date: 02/06/2014
INMP405
PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS
Figure 2. Pin Configuration
TABLE 4. PIN FUNCTION DESCRIPTIONS
PIN NAME FUNCTION
1
OUTPUT
Analog Output Signal
2 GND Ground
3 VDD Power Supply
GNDOUTPUT
TOP VIEW
(TERMINAL SIDE DOWN)
Not to Scale
INMP405
1
VDD
3
2
Page 6 of 13
Document Number: DS-INMP405-00
Revision: 1.0.
Rev Date: 02/06/2014
INMP405
TYPICAL PERFORMANCE CHARACTERISTICS
Figure 3. Frequency Response Mask
Figure 4. Typical Frequency Response (Measured)
Figure 5. Typical Power Supply Rejection Ratio vs. Frequency
–10
–8
–6
–4
–2
0
2
4
6
8
10
100 10k1k
FRE QUENCY ( Hz )
SENSITIVI T Y (d B)
10
–20
100
FRE QUENCY ( Hz )
(dB)
1k 10k
0
–10
0
–80
100 10k
FREQUENCY (Hz)
PSR (dB)
1k
–10
–20
–30
–40
–50
–60
–70
Page 7 of 13
Document Number: DS-INMP405-00
Revision: 1.0.
Rev Date: 02/06/2014
INMP405
APPLICATIONS INFORMATION
CONNECTING TO AUDIO CODECS
The INMP405 output can be connected to a dedicated codec microphone input (see Figure 6) or to a high input impedance gain
stage (see Figure 7.) A 0.1 µF ceramic capacitor placed close to the INMP405 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 6 because the input impedance of codecs 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 7 shows the INMP405 connected to an op
amp configured as a non-inverting preamplifier.
Figure 6. INMP405 Connected to a Codec
Figure 7. INMP405 Connected to an Op Amp
GAIN = (R1 + R2)/R1
INMP405
GND
OUTPUT
1µF
MINIMUM
0.1µF
10kΩ
R1 R2
VDD
VREF
VOUT
VREF
AMP
1.8- 3.3 V
ADC
OR
CODEC
IN
M
P
405
G
N
D
O
U
T
P
U
T
INPUT
M
I
CB
I
A
S
2
.
2
µ
F
M
I
N
I
M
U
M
0
.
1
µ
F
VDD
Page 8 of 13
Document Number: DS-INMP405-00
Revision: 1.0.
Rev Date: 02/06/2014
INMP405
SUPPORTING DOCUMENTS
For additional information, see the following documents.
EVALUATION BOARD USER GUIDE
UG-325 Analog Output MEMS Microphone Flex Evaluation Board
APPLICATION NOTE (PRODUCT SPECIFIC)
AN-0207 High Performance Analog MEMS Microphone’s Simple Interface to SigmaDSP Audio Codec
AN-0262 Low Noise Analog MEMS Microphone and Preamp with Compression and Noise Gating
APPLICATION NOTES (GENERAL)
AN-1003 Recommendations for Mounting and Connecting the Invensense Bottom-Ported MEMS Microphones
AN-1068 Reflow Soldering of the MEMS Microphone
AN-1112 Microphone Specifications Explained
AN-1124 Recommendations for Sealing Invensense, Bottom-Port MEMS Microphones from Dust and Liquid Ingress
AN-1140 Microphone Array Beamforming
AN-1165 Op Amps for MEMS Microphone Preamp Circuits
AN-1181 Using a MEMS Microphone in a 2-Wire Microphone Circuit
Page 9 of 13
Document Number: DS-INMP405-00
Revision: 1.0.
Rev Date: 02/06/2014
INMP405
PCB DESIGN AND LAND PATTERN LAYOUT
The recommended PCB land pattern for the INMP405 should be laid out to a 1:1 ratio to the solder pads on the microphone
package, as shown in Figure 8. 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 9. 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.
Figure 8. PCB Land Pattern Layout
Dimensions shown in millimeters
Figure 9. Suggested Solder Paste Stencil Pattern Layout
Dimensions shown in millimeters
Ø1.55
Ø0.95
1.52
0.90
1.90
1.22
0.68
0.61
0.61
1.22
2×0.8 × 0.6
0.2 × 45
TYP 1.52mm
1.55/ 1.05 DI A.
0.225 CUT WIDTH ( 2× )
Page 10 of 13
Document Number: DS-INMP405-00
Revision: 1.0.
Rev Date: 02/06/2014
INMP405
HANDLING INSTRUCTIONS
PICK AND PLACE EQUIPMENT
The MEMS microphone can be handled using standard pick-and-place and chip shooting equipment. Take care 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.
• 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 must 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 1 and Table 3.
BOARD WASH
When washing the PCB, ensure that water does not make contact with the microphone port. Do not use blow-off procedures or
ultrasonic cleaning.
Page 11 of 13
Document Number: DS-INMP405-00
Revision: 1.0.
Rev Date: 02/06/2014
INMP405
OUTLINE DIMENSIONS
Figure 10. 3-Terminal Chip Array Small Outline No-Lead Cavity [LGA_CAV]
3.35 × 2.50 mm Body
Dimensions shown in millimeters
Figure 11. Package Marking Specification (Top View)
ORDERING GUIDE
PART
TEMP RANGE
PACKAGE
QUANTITY
INMP405ACEZ-R01 *
−40°C to +85°C
3-Terminal LGA_CAV
10,000
INMP405ACEZ-R71†
−40°C to +85°C
3-Terminal LGA_CAV
1,000
EV_INMP405-FX
—
Flex Evaluation Board
—
* – 13” Tape and Reel
† – 7” Tape and reel to be discontinued. Check with sales@invensense.com for availability.
1Z = RoHS-Compliant Part
REVISION HISTORY
REVISION DATE REVISION DESCRIPTION
02/06/2014 1.0 Initial Release
2.575
2.500
2.425
3.425
3.350
3.275
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 MINDIA.
THRU HOLE
(SOUND PORT)
1.22 BSC 1.25
0.54
REF
0.64 REF
1.56 DIA.
1.52
0.75 REF
1
3
2
0.90×0.68
(PINS1,3)
0.20 TYP
×45°
0.30 BSC
PIN1
Y
Y
XXX
4
05
L
O
T TR
A
C
E
ABILITY
C
ODE
PIN 1 INDIC
A
TION
P
A
R
T NUMBER
D
A
TE
C
ODE
Page 12 of 13
Document Number: DS-INMP405-00
Revision: 1.0
Rev Date: 02/06/2014
INMP405
Compliance Declaration Disclaimer:
InvenSense believes this compliance information to be correct but cannot guarantee accuracy or completeness. Conformity
documents for the above component constitutes are on file. InvenSense subcontracts manufacturing and the information contained
herein is based on data received from vendors and suppliers, which has not been validated by InvenSense.
Environmental Declaration Disclaimer:
InvenSense believes this environmental information to be correct but cannot guarantee accuracy or completeness. Conformity
documents for the above component constitutes are on file. InvenSense subcontracts manufacturing and the information contained
herein is based on data received from vendors and suppliers, which has not been validated by InvenSense.
This information furnished by InvenSense, Inc. is believed to be accurate and reliable. However, no responsibility is assumed by
InvenSense for its use, or for any infringements of patents or other rights of third parties that may result from its use. Specifications
are subject to change without notice. InvenSense reserves the right to make changes to this product, including its circuits and
software, in order to improve its design and/or performance, without prior notice. InvenSense makes no warranties, neither
expressed nor implied, regarding the information and specifications contained in this document. InvenSense assumes no
responsibility for any claims or damages arising from information contained in this document, or from the use of products and
services detailed therein. This includes, but is not limited to, claims or damages based on the infringement of patents, copyrights,
mask work and/or other intellectual property rights.
Certain intellectual property owned by InvenSense and described in this document is patent protected. No license is granted by
implication or otherwise under any patent or patent rights of InvenSense. This publication supersedes and replaces all information
previously supplied. Trademarks that are registered trademarks are the property of their respective companies. InvenSense sensors
should not be used or sold in the development, storage, production or utilization of any conventional or mass-destructive weapons
or for any other weapons or life threatening applications, as well as in any other life critical applications such as medical equipment,
transportation, aerospace and nuclear instruments, undersea equipment, power plant equipment, disaster prevention and crime
prevention equipment.
©2014 InvenSense, Inc. All rights reserved. InvenSense, MotionTracking, MotionProcessing, MotionProcessor, MotionFusion,
MotionApps, DMP, AAR, and the InvenSense logo are trademarks of InvenSense, Inc. Other company and product names may be
trademarks of the respective companies with which they are associated.
©2014 InvenSense, Inc. All rights reserved.
Page 13 of 13
Document Number: DS-INMP405-00
Revision: 1.0
Rev Date: 02/06/2014
