AKU342
Analog Silicon MEMS Microphone
Data Sheet
DS28-1.04
Page 1
10Oct2014
© Akustica, Inc. reserves all rights even in the event of industrial property rights. We reserve all rights of disposal such
as copying and passing on to third parties. Bosch Group and the symbol are registered trademarks of Robert Bosch
GmbH, Germany. Note: Specifications within this document are subject to change without notice.
Data Sheet
Part number(s)
AKU342
Package type
6-pin LGA bottom port
Data sheet revision
1.04
Release date
10 October 2014
Document number
DS28-1.04 AKU342 Data Sheet
Notes
Specifications are subject to change without notice.
Product photos and pictures are for illustration purposes only and may differ
from the real product’s appearance.
Data Sheet
AKU342
Bottom port, Analog Silicon MEMS Microphone
AKU342
Analog Silicon MEMS Microphone
Data Sheet
DS28-1.04
Page 2
10Oct2014
© Akustica, Inc. reserves all rights even in the event of industrial property rights. We reserve all rights of disposal such
as copying and passing on to third parties. Bosch Group and the symbol are registered trademarks of Robert Bosch
GmbH, Germany. Note: Specifications within this document are subject to change without notice.
AKU342
Analog, HD Voice Silicon MEMS Microphone
General Description
AKU342 is an HD Voice quality, bottom port,
analog output silicon MEMS IC microphone. It
is an integrated circuit (IC) consisting of a
MEMS acoustic sensor, a pre-amplifier, charge
pump, and supporting circuitry in an industry
standard package footprint of 2.95mm x
3.76mm x 1.00mm.
Designed specifically to meet the demanding
requirements of mobile handset OEMs,
AKU342 offers excellent acoustic performance
with 63dB signal-to-noise ratio (SNR) and tight
sensitivity matching of just +/-2dB between
microphones. It also offers a flat wideband
frequency response with less than 5dB
variations from 50 Hz to 14 kHz, delivering
uniform audio capture across a broad audio
spectrum. The AKU342 metal lid package is
immune to RF and Electromagnetic (EM)
interferences, allowing for easy integration into
wireless devices.
Key Features
Bottom port, Analog output
Omni-directional audio sensor
Excellent acoustic performance: 63dB SNR
Tight sensitivity tolerance: -38dB +/- 2 dB
Matched microphones in frequency and
phase response for array applications
Flat frequency response for super-
wideband audio
Package immune to RF/EM interference
Lead-free, surface-mountable and RoHS2
compliant
Halogen-free in accordance with IEC61249-
2-21
Thin profile, SMT packaging
Industry-standard package of: 2.95 x 3.76 x
1.00 mm3
Typical Applications
Smartphones and mobile phones which
require high quality acoustic performance in
a small form factor microphone
Digital still/video cameras
IC / digital voice recorders
Portable media players
Gaming consoles / controllers
Voice activated entertainments systems
and remote controllers
Smart-home sensor hubs / clusters, and
IoTS acoustic sensor nodes
Microphone arrays – multi-mic applications
and noise cancellation algorithms which
benefit from microphones with tightly
matched sensitivity and phase
Products designed to capture super-
wideband audio that require a microphone
with less than 5dB variation in frequency
response from 50Hz-14kHz
Other small, thin consumer electronic
devices using more than one microphone
AKU342
Analog Silicon MEMS Microphone
Data Sheet
DS28-1.04
Page 3
10Oct2014
© Akustica, Inc. reserves all rights even in the event of industrial property rights. We reserve all rights of disposal such
as copying and passing on to third parties. Bosch Group and the symbol are registered trademarks of Robert Bosch
GmbH, Germany. Note: Specifications within this document are subject to change without notice.
Index of Contents
1. ABSOLUTE MAXIMUM RATINGS ........................................................................................................... 4
2. STANDARD OPERATING CONDITIONS ................................................................................................ 4
3. ELECTRICAL AND ACOUSTIC SPECIFICATIONS ............................................................................... 4
4. DEVICE CHARACTERISTICS ................................................................................................................. 5
4.1 Typical Frequency Response
4.2 IDD vs. VDD
4.3 Sensitivity vs. VDD
4.4 Total Harmonic Distortion
4.5 Sensitivity vs. Temperature
4.6 PSRR vs. Frequency
5. MECHANICAL SPECIFICATIONS ........................................................................................................... 6
6. PIN-OUT AND CONNECTION DIAGRAMS ............................................................................................. 7
6.1 Pin Out
6.2 Schematic
7. MANUFACTURING NOTES ...............................................................................................................8-10
7.1 Solder Reflow
7.2 Part Handling
7.3 PCB Land Pattern & Stencil Pattern
8. RELIABILITY SPECIFICATIONS ........................................................................................................... 11
9. PART MARKING INFORMATION .......................................................................................................... 11
10. PACKAGING INFORMATION .............................................................................................................. 12
11. ORDERING INFORMATION ................................................................................................................ 13
12. DOCUMENT REVISIONS ..................................................................................................................... 13
AKU342
Analog Silicon MEMS Microphone
Data Sheet
DS28-1.04
Page 4
10Oct2014
© Akustica, Inc. reserves all rights even in the event of industrial property rights. We reserve all rights of disposal such
as copying and passing on to third parties. Bosch Group and the symbol are registered trademarks of Robert Bosch
GmbH, Germany. Note: Specifications within this document are subject to change without notice.
1. ABSOLUTE MAXIMUM RATINGS
Supply Voltage, VDD to GND 5.5V
ESD Tolerance
Human Body Model 2000V
Machine Model 200V
Storage Temperature Range -40°C to 105°C
2. STANDARD OPERATING CONDITIONS
Operating Temperature Range -40°C to 85°C
Supply Voltage (VDD) 1.6V to 3.6V
3. ELECTRICAL AND ACOUSTIC SPECIFICATIONS
Unless otherwise noted, test conditions are:
VDD = 2.0V Ta = 25°C RH = 50%
Parameter
Test Conditions
Min.
Typ.
Max.
Unit
Directivity
Omni-directional
Signal to Noise Ratio (SNR)
fin = 1 kHz, A-weighted, 20Hz-10kHz
63
dB
Low Frequency Corner
-3dB from 1kHz sensitivity value
60
Hz
Upper Frequency Corner
+3dB from 1kHz sensitivity value
10
kHz
Sensitivity1
1kHz, 94dB SPL
-40
-38
-36
dBV/Pa
Total Harmonic Distortion
(THD)1
@ 94dB SPL, fin = 1 kHz
1
%
@ 114dB SPL, fin = 1 kHz
5
Power Supply Rejection
Ratio (PSRR)
100mVpp, f = 217Hz
60
dB
Current Consumption1
No load
300
A
Output Impedance
200
Sensitivity loss across
voltage
Change in sensitivity over 3.6V to
1.6V
0
dB
Part-to-part phase matching
From nominal @ 1kHz
±10
°
Polarity
Increasing sound pressure
Increasing output voltage
Note 1: Parameter 100% tested
AKU342
Analog Silicon MEMS Microphone
Data Sheet
DS28-1.04
Page 5
10Oct2014
© Akustica, Inc. reserves all rights even in the event of industrial property rights. We reserve all rights of disposal such
as copying and passing on to third parties. Bosch Group and the symbol are registered trademarks of Robert Bosch
GmbH, Germany. Note: Specifications within this document are subject to change without notice.
4. DEVICE CHARACTERISTICS
4.1 Frequency Response
(Measured frequency response normalized to
1kHz)
4.2 IDD vs. VDD
(Measured current consumption relative to
supply voltage)
4.3 Sensitivity vs. VDD
(Measured sensitivity changes relative to supply
voltage)
4.4 Total Harmonic Distortion
(Measured THD relative to speaker output
pressure level)
4.5 Sensitivity vs. Temperature
(Typical sensitivity changes relative to
temperature)
4.6 PSRR vs. Frequency
(Typical PSRR relative to frequency)
-10
-5
0
5
10
15
10 100 1000 10000
Normalized Microphone Output re:1kHz
Mo
Frequency, (Hz)
150
175
200
225
250
275
300
325
350
1 1.5 2 2.5 3 3.5 4 4.5
IDD, (µA)
VDD, (V)
-0.5
-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
0.4
0.5
1.6 2.1 2.6 3.1 3.6
Output(dB), VDD = 1.8V
VDD, (V)
0
5
10
15
20
THD, (%)
Speaker Output Pressure, (dBSPL)
-0.6
-0.5
-0.4
-0.3
-0.2
-0.1
-1E-15
0.1
0.2
0.3
0.4
0.5
0.6
-60 -40 -20 020 40 60 80 100
Change in Sensitivity, re: 25C
Temperature, (ºC)
30
40
50
60
70
100 1000 10000 100000
PSRR (dB)
Frequency, (Hz)
AKU342
Analog Silicon MEMS Microphone
Data Sheet
DS28-1.04
Page 6
10Oct2014
© Akustica, Inc. reserves all rights even in the event of industrial property rights. We reserve all rights of disposal such
as copying and passing on to third parties. Bosch Group and the symbol are registered trademarks of Robert Bosch
GmbH, Germany. Note: Specifications within this document are subject to change without notice.
5. MECHANICAL SPECIFICATIONS
Item
Dimension
Tolerance
Units
Length (L)
3.76
± 0.10
mm
Width (W)
2.95
± 0.10
mm
Height (H)
1.00
± 0.10
mm
Acoustic Port (AP)
0.30
± 0.03
mm
Planarity
Top/Bottom
± 0.05
mm
All dimensions in mm
Tolerance ± 0.05mm unless otherwise specified
Bottom View
Top View
Side View
1
5
4
2
3
6
1
4
2
3
AKU342
Analog Silicon MEMS Microphone
Data Sheet
DS28-1.04
Page 7
10Oct2014
© Akustica, Inc. reserves all rights even in the event of industrial property rights. We reserve all rights of disposal such
as copying and passing on to third parties. Bosch Group and the symbol are registered trademarks of Robert Bosch
GmbH, Germany. Note: Specifications within this document are subject to change without notice.
6. PIN-OUT AND CONNECTION DIAGRAMS
6.1 Pin-Out
(As viewed from bottom of package)
6.2 Typical Application Schematic
Pin
Name
Function
1
OUT
Analog output voltage
2
GND
Ground
3
NC/GND1
No Connect or Ground
4
VDD
Power supply voltage for microphone
5, 6
GND
Ground
Note 1: Pin 2 must be Ground. Pin 3 can be left as
No Connect or tied to Ground.
5
4
3
6
AKU342
Analog Silicon MEMS Microphone
Data Sheet
DS28-1.04
Page 8
10Oct2014
© Akustica, Inc. reserves all rights even in the event of industrial property rights. We reserve all rights of disposal such
as copying and passing on to third parties. Bosch Group and the symbol are registered trademarks of Robert Bosch
GmbH, Germany. Note: Specifications within this document are subject to change without notice.
7. MANUFACTURING NOTES
7.1 Solder Reflow
Typical solder reflow profile
Average ramp-up rate
max. 3°C/s
Time ts between Tsmin (150°C) and Tsmax (200°C)
60s – 120s
Time tL above liquidous temperature TL (217°C)
60s – 90s
Peak temperature TP
max. 260°C
Time tP at TP
max. 20s
Average ramp-down rate
max. 6°C/s
Note: It is recommended to fine-tune the reflow process to optimize for variations in materials,
environment, handling, PCB board size and thickness, etc.
Please refer to AN60-Handling, Soldering, and Mounting Instructions for more detailed information
and precautions.
AKU342
Analog Silicon MEMS Microphone
Data Sheet
DS28-1.04
Page 9
10Oct2014
© Akustica, Inc. reserves all rights even in the event of industrial property rights. We reserve all rights of disposal such
as copying and passing on to third parties. Bosch Group and the symbol are registered trademarks of Robert Bosch
GmbH, Germany. Note: Specifications within this document are subject to change without notice.
7.2. Microphone Handling
Although the microphone may not appear damaged immediately due to inappropriate handling,
there can be long term effects that affect the lifetime of the component.
Rule of thumb: The microphone is an artificial ear so treat it like your own ear.
Do not blow air into the acoustic port of the microphone for any reason. Do not subject it to
pressurized air
- e.g. when cleaning the board or other components on the same board
Do not apply vacuum to the acoustic port of the microphone
Do not insert liquids
- If populated circuit boards are washed, the microphone must be protected
Do not insert dust
- The production facilities must be clean
- e.g. if PCB routing/sawing is done close to the microphone after SMT assembly and
reflow
Do not insert any objects
- If assembly or rework is done manually, care must be taken that the tools cannot enter
the microphone sound port
- It is best to choose tool size so that it does not fit through the sound port of the
microphone
Do not cover the acoustic port with tape when heating during assembly or reflow
Do not apply extreme mechanical stresses on the microphone, including mechanical
shocks above 10kG or compression of the microphone package.
After a bottom port microphone has been assembled on a circuit board, protect the sound
port (now on the other side of the board) from dust, liquids, and other foreign materials as
well as any tools and pressurized air.
ESD Handling Procedures
Follow CMOS handling procedures with Akustica MEMS microphones. Handle the
microphone with proper workplace grounding to include wrist straps and ionized
airflow over open trays and reels of microphones. Do not hot-swap/hot-plug during
testing. Device pins have ESD ratings of 2kV/200V for HBM/MM respectively.
AKU342
Analog Silicon MEMS Microphone
Data Sheet
DS28-1.04
Page 10
10Oct2014
© Akustica, Inc. reserves all rights even in the event of industrial property rights. We reserve all rights of disposal such
as copying and passing on to third parties. Bosch Group and the symbol are registered trademarks of Robert Bosch
GmbH, Germany. Note: Specifications within this document are subject to change without notice.
7.3 PCB Land Pattern and Stencil Pattern
Note: Stencil printer settings will likely require minor optimizations when transferring this stencil
pattern to a high volume production printer.
Please refer to AN60-Handling, Soldering, and Mounting Instructions for more detailed information
and precautions.
PCB Land
Pattern Layout
Suggested Solder Paste
Stencil Pattern Layout
1
5
4
2
3
6
Acoustic port (PCB must be drilled here)
AKU342
Analog Silicon MEMS Microphone
Data Sheet
DS28-1.04
Page 11
10Oct2014
© Akustica, Inc. reserves all rights even in the event of industrial property rights. We reserve all rights of disposal such
as copying and passing on to third parties. Bosch Group and the symbol are registered trademarks of Robert Bosch
GmbH, Germany. Note: Specifications within this document are subject to change without notice.
8. RELIABILITY SPECIFICATIONS
The microphone sensitivity after stress must deviate by no more than 3dB from the initial value.
Test
Test Condition
1
Cold Temp Operation
Temperature = -40°C, 1000 hours (with bias)
2
Hot Temp Operation
Temperature = 105°C, 1000 hours (with bias)
3
Humidity Operation
Temperature = 85°C, RH = 85%, 1000 hours (with bias)
4
Cold Temp Storage
Temperature = -40°C, 1000 hours (without bias)
5
Hot Temp Storage
Temperature = 105°C, 1000 hours (without bias)
6
Humidity Storage
Temperature = 85°C, RH = 85%, 1000 hours (without bias)
7
Thermal Cycle
100 Cycles, -40°C to +125°C, 15min soaks, <30sec ramps
8
Vibration
Sinusoidal Vibration, 20Hz-2000Hz, 4min sweeps, 16min along each
of 3 axis, amplitude 3 limits of 20G and 0.06”
9
Mechanical Shock
10,000G shocks, 5 impacts along each of 6 axes
10
Drop Test
Using 150gm aluminum fixture, 3 drops along each of 6 axes (total 18
drops) from 1.5m height onto concrete drop surface.
11
ESD (HBM)
+/-2000V, 1 discharge for each polarity, 11 pin combinations, 22 total
discharges per microphone
12
ESD (MM)
+/- 200V, 1 discharge for each polarity, 11 pin combinations, 22 total
discharges per microphone
13
ESD
+/- 8kV, contact discharge to lid with DUT grounded
14
Moisture Sensitivity
Level
24 hour bake at 125°C, followed by 168 hours at 85°C, 85%RH,
followed by 3 passes solder reflow (MSL Level 1)
9. PART MARKING INFORMATION
Line 1: A342X (A = Akustica, Part Code = 342, X =
Assembly Facility)
Line 2: WWYLL (WW = Work Week, Y = Year, LL =
Lot Number Processed During Work Week)
Acoustic
Port
AKU342
Analog Silicon MEMS Microphone
Data Sheet
DS28-1.04
Page 12
10Oct2014
© Akustica, Inc. reserves all rights even in the event of industrial property rights. We reserve all rights of disposal such
as copying and passing on to third parties. Bosch Group and the symbol are registered trademarks of Robert Bosch
GmbH, Germany. Note: Specifications within this document are subject to change without notice.
10. PACKAGING INFORMATION
10.1 Tape Specification
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. Ao and Bo are calculated on a plane at a distance of “R” above the bottom of the pocket.
10.2 Component Orientation
Ao = 4.16
Bo = 3.40
Ko = 1.30
Pin 1
Location
AKU342
Analog Silicon MEMS Microphone
Data Sheet
DS28-1.04
Page 13
10Oct2014
© Akustica, Inc. reserves all rights even in the event of industrial property rights. We reserve all rights of disposal such
as copying and passing on to third parties. Bosch Group and the symbol are registered trademarks of Robert Bosch
GmbH, Germany. Note: Specifications within this document are subject to change without notice.
11. ORDERING INFORMATION
Part
Number
Order Number1
Part Code
Package
Shipping
Method
Standard
Quantity
AKU342
02730A0008
02730A3003
A342
6-Pad LGA
13” Reel
5,700
Note 1: Please contact Akustica to determine the appropriate order number when placing an order.
12. DOCUMENT REVISIONS
Rev. No
Description of modification/changes
Date
1.0
Updated for final. Released 1.0.
13-Jun-13
1.01
Updated order number to 3003 from 0003.
23-Aug-13
1.02
Updated order numbers for new order code system. RoHS
compliance to RoHS2. Added pin identification numbers
15-Oct-13
1.03
Edited cover page. Reformatted the part description / general
description page (pg. 2). Updated footnote regarding AN60 in
section 7.
10-Feb-14
1.04
Updated headers and PCB layout AP
10-Oct-14
Akustica, Inc.
2835 E Carson St. Suite 301
Pittsburgh, PA / USA 15203
(412) 390-1730
sales@akustica.com
www.akustica.com/contact.asp
Modifications reserved | Printed in USA
Specifications subject to change without notice
