WM7230/30E 製品データシート

WM7230, WM7230E
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Bottom Port Digital Silicon Microphone
DESCRIPTION
FEATURES
The WM7230 is a low-profile silicon digital microphone. It
offers high Signal to Noise Ratio (SNR) and low power
consumption and is suited to a wide variety of consumer
applications.
•
•
The WM7230 incorporates Wolfson’s proprietary
CMOS/MEMS membrane technology, offering high
reliability and high performance in a miniature, low-profile
package. The WM7230 is designed to withstand the high
temperatures associated with automated flow solder
assembly processes. (Note that conventional microphones
can be damaged by this process.)
•
The WM7230 incorporates a high performance ADC,
which outputs a single-bit data stream using Pulse Density
Modulation (PDM) encoding. The WM7230 supports
selectable left/right channel assignment for a two-channel
digital microphone interface, enabling efficient connection
of multiple microphones in stereo/array configurations.
The WM7230E variant offers a tighter tolerance on the
microphone sensitivity, giving reduced variation between
parts. This removes the need for in-line production
calibration of part-to-part microphone variations.
The WM7230 and WM7230E are footprint-compatible with
other WM723X microphones, enabling direct drop-in
replacement.
BLOCK DIAGRAM
•
•
•
•
•
High SNR (61dB)
Low variation in sensitivity
±3dB tolerance (WM7230)
±1dB tolerance (WM7230E)
Low current consumption
2μA (Sleep)
735μA (Normal operation)
PDM Digital audio output
Stereo/array operation
Proprietary ADC technology
Reduced clock jitter sensitivity
Low noise floor modulation
Stable in overload condition
Bottom Port LGA Package (WM723X compatible)
1.64V to 3.7V supply
APPLICATIONS
•
•
•
•
•
•
•
Mobile telephone handsets
Portable computers
Portable media players
Digital still cameras
Digital video cameras
Bluetooth headsets
Portable navigation devices
3D VIEW
VDD
W
WM7230
CLK
CONTROL
CHARGE
PUMP
AMP
DAT
LRSEL
ADC
CMOS MEMS
Transducer
GND
WOLFSON MICROELECTRONICS plc
4.00mm x 3.00mm x 1.00mm LGA package
Pre-Production, October 2014, Rev 3.2
Copyright 2014 Wolfson Microelectronics plc
WM7230, WM7230E
Pre-Production
TABLE OF CONTENTS
DESCRIPTION ................................................................................................................ 1
FEATURES ..................................................................................................................... 1
APPLICATIONS .............................................................................................................. 1
BLOCK DIAGRAM.......................................................................................................... 1
3D VIEW ......................................................................................................................... 1
TABLE OF CONTENTS .................................................................................................. 2
PIN CONFIGURATION ................................................................................................... 3
PIN DESCRIPTION ......................................................................................................... 3
ORDERING INFORMATION ........................................................................................... 3
ABSOLUTE MAXIMUM RATINGS ................................................................................. 4
IMPORTANT ASSEMBLY GUIDELINES ....................................................................... 4
RECOMMENDED OPERATING CONDITIONS .............................................................. 4
ACOUSTIC AND ELECTRICAL CHARACTERISTICS................................................... 5
TERMINOLOGY ...................................................................................................................... 6
AUDIO INTERFACE TIMING .................................................................................................. 7
TYPICAL PERFORMANCE ............................................................................................ 8
APPLICATIONS INFORMATION.................................................................................... 9
RECOMMENDED EXTERNAL COMPONENTS ...................................................................... 9
OPTIMISED SYSTEM RF DESIGN ......................................................................................... 9
CONNECTION TO A WOLFSON AUDIO CODEC .................................................................. 9
PCB LAND PATTERN AND PASTE STENCIL .......................................................................10
PACKAGE DIMENSIONS ............................................................................................. 11
IMPORTANT NOTICE .................................................................................................. 12
ADDRESS: .............................................................................................................................12
REVISION HISTORY .................................................................................................... 13
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PIN CONFIGURATION
4
3
5
2
1
TOP VIEW
PIN DESCRIPTION
PIN
NAME
TYPE
1
CLK
Digital Input
DESCRIPTION
2
DAT
Digital Output
3
VDD
Supply
Power Supply
4
GND
Supply
Ground
5
LRSEL
Digital Input
Clock input
PDM Data Output
Channel Select
0 = Data output following falling CLK edge
1 = Data output following rising CLK edge
Internal pull-down holds this pin at logic 0 when not connected
ORDERING INFORMATION
DEVICE
DESCRIPTION
TEMPERATURE
RANGE
MOISTURE
SENSITIVITY LEVEL
PEAK SOLDERING
TEMPERATURE
WM7230IMS/RV
Standard
(tape and reel)
-40 to +100°C
MSL2A
+260°C
WM7230IMSE/RV
Standard Enhanced
(tape and reel)
-40 to +100°C
MSL2A
+260°C
Note:
Reel quantity = 4800
All devices are Pb-free and Halogen free.
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ABSOLUTE MAXIMUM RATINGS
Absolute Maximum Ratings are stress ratings only. Permanent damage to the device may be caused by continuously operating at
or beyond these limits. Device functional operating limits and guaranteed performance specifications are given under Electrical
Characteristics at the test conditions specified.
ESD Sensitive Device. This device is manufactured on a CMOS process. It is therefore generically susceptible
to damage from excessive static voltages. Proper ESD precautions must be taken during handling and storage
of this device.
Wolfson tests its package types according to IPC/JEDEC J-STD-020 for Moisture Sensitivity to determine acceptable storage
conditions prior to surface mount assembly. These levels are:
MSL1 = unlimited floor life at <30°C / 85% Relative Humidity. Not normally stored in moisture barrier bag.
MSL2 = out of bag storage for 1 year at <30°C / 60% Relative Humidity. Supplied in moisture barrier bag.
MSL2A = out of bag storage for 4 weeks at <30°C / 60% Relative Humidity. Supplied in moisture barrier bag.
MSL3 = out of bag storage for 168 hours at <30°C / 60% Relative Humidity. Supplied in moisture barrier bag.
The Moisture Sensitivity Level for each package type is specified in Ordering Information.
CONDITION
MIN
Supply Voltage (VDD)
Voltage range digital inputs (LRSEL, CLK)
Operating temperature range, TA
MAX
-0.3V
+4.2V
GND - 0.3V
VDD + 0.3V
-40°C
+100°C
Storage temperature prior to soldering
30°C max / 60% RH max
Storage temperature after soldering
-40°C
+100°C
IMPORTANT ASSEMBLY GUIDELINES
Do not put a vacuum over the port hole of the microphone. Placing a vacuum over the port hole can damage the device.
Do not board wash the microphone after a re-flow process. Board washing and the associated cleaning agents can damage the
device. Do not expose to ultrasonic cleaning methods.
Do not use vapour phase re-flow process. The vapour can damage the device.
Please refer to application note WAN0273 (MEMS MIC Assembly and Handling Guidelines) for further assembly and handling
guidelines.
RECOMMENDED OPERATING CONDITIONS
SYMBOL
MIN
VDD Supply Range
PARAMETER
VDD
1.64
Ground
GND
Clock Frequency
FCLK
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TYP
MAX
UNIT
3.7
V
3.25
MHz
0
1
V
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ACOUSTIC AND ELECTRICAL CHARACTERISTICS
Test Conditions: VDD=1.8V, 1kHz test signal, CLK=2.4MHz, TA = 25°C, unless otherwise stated.
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
Directivity
TYP
MAX
UNIT
Omni-directional
Polarity (see note)
Positive sound pressure
Decreasing density of 1s
Sensitivity (WM7230)
S
94 dB SPL
-29
-26
-23
dBFS
Sensitivity (WM7230E)
S
94 dB SPL
-27
-26
-25
dBFS
Acoustic Overload
Total Harmonic Distortion
Signal to Noise Ratio
Dynamic Range
THD
No load, THD < 10%
120
100dB SPL
0.1
114dB SPL
0.5
%
117.5dB SPL
1
SNR
A-weighted
61
DR
A-weighted
84.5
dB
A-weighted
33
dB SPL
dBFS
Acoustic Noise Floor
Electrical Noise Floor
A-weighted
-87
Frequency Response
+3dB high frequency
17000
Frequency Response Flatness
Power Supply Rejection
dB SPL
1
200Hz to 8kHz
PSR
-1
217Hz square wave,
100mV (peak-peak)
dB
Hz
+1
-75
dB
dBFS
Digital Input / Output
CLK Input HIGH Level
VIH
0.65 x
VDD
CLK Input LOW Level
VIL
DAT Output HIGH Level
VOH
IOH = +1mA
DAT Output LOW Level
VOL
IOL = -1mA
V
0.35 x
VDD
Input capacitance (CLK)
0.9 x
VDD
V
V
0.1 x
VDD
V
1
μA
100
pF
10
mA
0.5
Input leakage
Maximum load capacitance
(DAT)
CLOAD
Short Circuit Output Current
ISC
DAT connected to GND
IVDD
Active Mode
735
Sleep Mode
2
From OFF
10
From Sleep
10
pF
Miscellaneous
Current Consumption
Start-up Time
CLK Sleep Frequency
μA
10
ms
1.0
kHz
Note: The WM7230 generates a single-bit digital (PDM) output in response to the acoustic input. A positive sound pressure on the
diaphragm generates a decreasing density of 1’s in the PDM stream (ie. there is a phase inversion between the acoustic input and
the digital output).
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TERMINOLOGY
1.
Sensitivity (dBFS) – Sensitivity is a measure of the microphone output response to the acoustic pressure of a 1kHz 94dB SPL
(1Pa RMS) sine wave. This is referenced to the output Full Scale Range (FSR) of the microphone.
2.
Full Scale Range (FSR) - Sensitivity, Electrical Noise Floor and Power Supply Rejection are measured with reference to the
output Full Scale Range (FSR) of the microphone. FSR is defined as the amplitude of a 1kHz sine wave output whose positive
peak value reaches 100% density of logic 1s and whose negative peak value reaches 0% density of logic 1s. This is the
largest 1kHz sine wave that will fit in the digital output range without clipping. Note that, because the definition of FSR is based
on a sine wave, it is possible to support a square wave test signal output whose level is +3dBFS.
3.
Total Harmonic Distortion (%) – THD is the ratio of the RMS sum of the harmonic distortion products in the specified
bandwidth (see note below) relative to the RMS amplitude of the fundamental (ie. test frequency) output.
4.
Signal-to-Noise Ratio (dB) – SNR is a measure of the difference in level between the output response of a 1kHz 94dB SPL
sine wave and the idle noise output.
5.
Dynamic Range (dB) – DR is the ratio of the 1% THD microphone output level (in response to a sine wave input) and the idle
noise output level.
6.
All performance measurements are carried out within a 20Hz to 20kHz bandwidth and, where noted, an A-weighted filter.
Failure to use these filters will result in higher THD and lower SNR values than are found in the Acoustic and Electrical
Characteristics. The brick wall filter removes out of band noise.
7.
Sleep Mode is enabled when the CLK input is below the CLK Sleep Frequency noted above. This is a power-saving mode.
Normal operation resumes automatically when the CLK input is above the CLK Sleep Frequency. Note that the VDD supply is
still required in Sleep mode.
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Pre-Production
AUDIO INTERFACE TIMING
tCY
CLK
(input)
DAT
(LRSEL = 1)
tL_DV
tL_DIS
tL_EN
tR_DV
DAT
(LRSEL = 0)
tR_DIS
tR_EN
DAT is high-impedance (hi-z) when not outputting data
Figure 1 Digital Microphone Interface Timing
Test Conditions
The following timing information is valid across the full range of recommended operating conditions.
PARAMETER
SYMBOL
MIN
TYP
MAX
UNIT
308
1000
ns
60:40
40:60
Digital Microphone Interface Timing
CLK cycle time
tCY
CLK duty cycle
CLK rise/fall time
DAT enable from rising CLK edge (LRSEL = 1)
tL_EN
14
DAT valid from rising CLK edge (LRSEL = 1)
tL_DV
20
DAT disable from falling CLK edge (LRSEL = 1)
tL_DIS
DAT enable from falling CLK edge (LRSEL = 0)
tR_EN
14
DAT valid from falling CLK edge (LRSEL = 0)
tR_DV
20
DAT disable from rising CLK edge (LRSEL = 0)
tR_DIS
6
ns
90
ns
16
ns
ns
ns
90
ns
16
ns
Notes:
1.
2.
3.
4.
The DAT output is high-impedance when not outputting data; this enables the outputs of two microphones to be connected
together with the data from one microphone interleaved with the data from the other. (The microphones must be configured to
transmit on opposite channels in this case.)
In a typical configuration, the Left channel is transmitted following the rising CLK edge (LRSEL = 1). In this case, the Left
channel should be sampled by the receiving device on the falling CLK edge.
Similarly, the Right channel is typically transmitted following the falling CLK edge (LRSEL = 0). In this case, the Right channel
should be sampled by the receiving device on the rising CLK edge.
The WM7230 operating mode is selected according to the CLK frequency; see “Acoustic and Electrical Characteristics” for
further details.
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TYPICAL PERFORMANCE
Sensitivity vs. Frequency
PSR vs. Frequency
Sensitivity vs. Supply Voltage
Current Consumption vs. Supply Voltage
THD vs. Sound Pressure Level
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APPLICATIONS INFORMATION
RECOMMENDED EXTERNAL COMPONENTS
It is recommended to connect a 0.1µF decoupling capacitor between the VDD and GND pins of the
WM7230. A ceramic 0.1µF capacitor with X7R dielectric or better is suitable. The capacitor should be
placed as close to the WM7230 as possible.
OPTIMISED SYSTEM RF DESIGN
For optimised RF design please refer to document WAN0278 (Recommended PCB Layout for
Microphone RF Immunity in Mobile Cell Phone Applications) for further information.
CONNECTION TO A WOLFSON AUDIO CODEC
Wolfson provides a range of audio CODECs incorporating a digital microphone input interface; these
support direction connection to digital microphones such as the WM7230.
Stereo connection of two WM7230 digital microphones is illustrated in Figure 2.
Further information on Wolfson audio CODECs is provided in the respective product datasheet, which
is available from the Wolfson website.
VDD
WM7230
VDD
Audio CODEC
CLK
0.1µF
DAT
LRSEL
DMICCLK
DMICDAT
GND
VDD
WM7230
VDD
CLK
0.1µF
DAT
LRSEL
GND
Figure 2 Stereo WM7230 Digital Microphone Connection
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Pre-Production
PCB LAND PATTERN AND PASTE STENCIL
The recommended PCB Land Pattern and Paste Stencil Pattern for the WM7236 microphone are
shown in Figure 3 and Figure 4.
See also Application Note WAN0284 (General Design Considerations for MEMS Microphones) for
further details of PCB footprint design.
Full definition of the package dimensions is provided in the “Package Dimensions” section.
Figure 3 DM089 - PCB Land Pattern, Top View
Figure 4 DM089 – Paste Stencil Pattern, Top View
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WM7230, WM7230E
PACKAGE DIMENSIONS
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IMPORTANT NOTICE
Wolfson Microelectronics plc (“Wolfson”) products and services are sold subject to Wolfson’s terms and conditions of sale, delivery
and payment supplied at the time of order acknowledgement.
Wolfson warrants performance of its products to the specifications in effect at the date of shipment. Wolfson reserves the right to
make changes to its products and specifications or to discontinue any product or service without notice. Customers should
therefore obtain the latest version of relevant information from Wolfson to verify that the information is current.
Testing and other quality control techniques are utilised to the extent Wolfson deems necessary to support its warranty. Specific
testing of all parameters of each device is not necessarily performed unless required by law or regulation.
In order to minimise risks associated with customer applications, the customer must use adequate design and operating
safeguards to minimise inherent or procedural hazards. Wolfson is not liable for applications assistance or customer product
design. The customer is solely responsible for its selection and use of Wolfson products. Wolfson is not liable for such selection
or use nor for use of any circuitry other than circuitry entirely embodied in a Wolfson product.
Wolfson’s products are not intended for use in life support systems, appliances, nuclear systems or systems where malfunction can
reasonably be expected to result in personal injury, death or severe property or environmental damage. Any use of products by the
customer for such purposes is at the customer’s own risk.
Wolfson does not grant any licence (express or implied) under any patent right, copyright, mask work right or other intellectual
property right of Wolfson covering or relating to any combination, machine, or process in which its products or services might be or
are used. Any provision or publication of any third party’s products or services does not constitute Wolfson’s approval, licence,
warranty or endorsement thereof. Any third party trade marks contained in this document belong to the respective third party
owner.
Reproduction of information from Wolfson datasheets is permissible only if reproduction is without alteration and is accompanied by
all associated copyright, proprietary and other notices (including this notice) and conditions.
Wolfson is not liable for any
unauthorised alteration of such information or for any reliance placed thereon.
Any representations made, warranties given, and/or liabilities accepted by any person which differ from those contained in this
datasheet or in Wolfson’s standard terms and conditions of sale, delivery and payment are made, given and/or accepted at that
person’s own risk. Wolfson is not liable for any such representations, warranties or liabilities or for any reliance placed thereon by
any person.
ADDRESS:
Wolfson Microelectronics plc
Westfield House
26 Westfield Road
Edinburgh
EH11 2QB
Tel :: +44 (0)131 272 7000
Fax :: +44 (0)131 272 7001
Email :: sales@wolfsonmicro.com
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REVISION HISTORY
DATE
REV
20/10/10
2.0
Front page description and features re-worded.
Description of LRSEL pin updated.
Electrical Characteristics re-ordered, and terminology updated.
Microphone interface timing drawing and descriptions updated.
Frequency response graph added.
Illustration of external components replaced with text.
Connection to Wolfson CODEC text and illustration updated.
Recommended PCB land patterns moved to Applications
Information.
DESCRIPTION OF CHANGES
26/10/10
2.0
Package Diagram DM089.D added
23/11/10
2.0
Specification of FSR corrected.
Specification for THD corrected
Time to data valid changed to minimum
Grammatical errors
CST
28/01/11
2.0
Reel quantity added to order information
JMacD
06/09/11
2.1
Updated the LRSEL pin description , Timing diagram and notes for
the rising and falling clock edges.
Sleep mode current updated to 2uA
Updated the reel quantity
Updated the start up time
Updated the new freq response and THD curves
Updated +3dB frequency cut off
Updated VDD to 1.64V
Package Diagram updated to DM089.E.
References and dimension letters changed to be consistent with all
mems package diagrams.
Lid dimensions updated.
Swapped dimensions L and E.
Added marking area boundary
JMacD
16/12/11
2.2
Introduced E variant with sensitivity +/-1dB
Added E variant ordering info
Added voltage range digital input
Updated the CODEC to WM8994
Added Reference to WAN_0273
22/06/12
2.3
Dynamic Range added, p5
Active mode current changed to 700uA, p1 and p5
CLK cycle time min and max updated, p6
Package Diagram updated to DM089F
08/10/12
2.4
Optimised System RF Design added.
JMacD
17/06/13
2.5
Package Diagram updated to DM089.G
JMacD
11/11/13
3.1
Updated to pre-production status.
Package Diagram updated – port hole tolerance added.
Updated CODEC reference to WM8280.
JMacD
18/12/13
3.1
Acoustic and Electrical Characteristics updated:
Polarity added, PSR updated, Note added
29/09/14
3.2
Formatting updates throughout document
Electrical Characteristics & Timing Requirements updated
Typical Performance graphs added
PCB Paste Stencil information & Package Drawing updated
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CHANGED BY
PH
JMacD
KC
MR/JMacD
MR
PH
5-7
8
10-11
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