ICS-41352
Bottom Port PDM Digital Output Multi-Mode
Microphone with Ultrasonic Mode
APPLICATIONS
GENERAL DESCRIPTION
The ICS-41352 is a multi-mode, low noise digital MEMS
microphone in a small package. The ICS-41352 consists of a
MEMS microphone element and an impedance converter
amplifier followed by a fourth-order Σ-Δ modulator. The digital
interface allows the pulse density modulated (PDM) output of
two microphones to be time multiplexed on a single data line
using a single clock.
The ICS-41352 has multiple modes of operation: Ultrasonic,
Low-Power (AlwaysOn), Standard and Sleep. The ICS-41352
has high SNR in all operational modes. It has 120 dB SPL AOP in
all performance modes.
In Ultrasonic Mode, the ICS-41352 has an extended ultrasonic
response up to 85 kHz with high SNR.
The ICS-41352 is available in a small 3.5 × 2.65 × 0.98 mm
surface-mount package. It is reflow solder compatible with
no sensitivity degradation.
FEATURES
SPEC
LOW-POWER
MODE
STANDARD
MODE
ULTRASONIC
MODE
Sensitivity
SNR
Current
AOP
Clock
−26 dB FS ±1 dB
63 dBA
185 µA
120 dB SPL
400 – 800 kHz
−26 dB FS ±1 dB
64 dBA
430 µA
120 dB SPL
1.0 – 3.3 MHz
−26 dB FS ±1 dB
64 dBA
550 µA
120 dB SPL
4.1 – 4.8 MHz
FUNCTIONAL BLOCK DIAGRAM
PART
PDM
MODULATOR
CLK
ICS-41352
TEMP RANGE
PACKAGING
−40°C to +85°C
13” Tape and Reel
DATA
CHANNEL
SELECT
SELECT
VDD
GND
POWER
MANAGEMENT
3.5 × 2.65 × 0.98 mm surface-mount package
Low power: 550 µA in Ultrasonic Mode, 185 µA in
Low-Power Mode
Extended ultrasonic frequency response to 85 kHz
Sleep Mode: 12 µA
High power supply rejection (PSR): −97 dB FS
Fourth-order Σ-Δ modulator
Digital pulse density modulation (PDM) output
Compatible with Sn/Pb and Pb-free solder processes
RoHS/WEEE compliant
ORDERING INFORMATION
ICS-41352
ADC
Smartphones
Microphone Arrays
Tablet Computers
Cameras
Bluetooth Headsets
Notebook PCs
Security and Surveillance
This document contains information on a preproduction
product. Specifications and information herein are
subject to change without notice.
InvenSense Inc.
1745 Technology Drive, San Jose, CA 95110 U.S.A
+1(408) 988–7339
www.invensense.com
Document Number: DS-000048
Revision: 1.0
Release Date: 9/30/2016
ICS-41352
TABLE OF CONTENTS
General Description ..................................................................................................................................................................... 1
Applications ................................................................................................................................................................................. 1
Features ....................................................................................................................................................................................... 1
Functional Block Diagram ............................................................................................................................................................ 1
Ordering Information ................................................................................................................................................................... 1
Table of Contents .................................................................................................................................................................................... 2
Specifications .......................................................................................................................................................................................... 4
Table 1. Acoustical/Electrical Characteristics – General .............................................................................................................. 4
Table 2. Acoustical/Electrical Characteristics – Ultrasonic Mode ................................................................................................ 4
Table 3. Acoustical/Electrical Characteristics – Standard Mode.................................................................................................. 5
Table 4. Acoustical/Electrical Characteristics – Low-Power Mode .............................................................................................. 5
Table 5. Digital Input/Output Characteristics .............................................................................................................................. 6
Table 6. PDM Digital Input/Output .............................................................................................................................................. 6
Timing Diagram ............................................................................................................................................................................ 7
Absolute Maximum Ratings .................................................................................................................................................................... 8
Table 7. Absolute Maximum Ratings ........................................................................................................................................... 8
ESD Caution ................................................................................................................................................................................. 8
Soldering Profile........................................................................................................................................................................... 9
Table 8. Recommended Soldering Profile* .................................................................................................................................. 9
Pin Configurations And Function Descriptions ..................................................................................................................................... 10
Table 9. Pin Function Descriptions............................................................................................................................................. 10
Typical Performance Characteristics ..................................................................................................................................................... 11
Theory Of Operation ............................................................................................................................................................................. 12
PDM Data Format ...................................................................................................................................................................... 12
Table 10. ICS-41352 Channel Setting ......................................................................................................................................... 12
PDM Microphone Sensitivity ..................................................................................................................................................... 12
ApplicationS Information ...................................................................................................................................................................... 14
Low Power Mode ....................................................................................................................................................................... 14
Dynamic Range Considerations ................................................................................................................................................. 14
Connecting PDM Microphones .................................................................................................................................................. 14
Ultrasound Applications ............................................................................................................................................................ 16
Sleep Mode ................................................................................................................................................................................ 16
Start-Up Time ............................................................................................................................................................................. 16
Supporting Documents ......................................................................................................................................................................... 17
Application Notes ...................................................................................................................................................................... 17
PCB Design And Land Pattern Layout ................................................................................................................................................... 18
PCB Material And Thickness ...................................................................................................................................................... 18
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ICS-41352
Handling Instructions ............................................................................................................................................................................ 19
Pick And Place Equipment ......................................................................................................................................................... 19
Reflow Solder ............................................................................................................................................................................. 19
Board Wash................................................................................................................................................................................ 19
Outline Dimensions ............................................................................................................................................................................... 20
Ordering Guide .......................................................................................................................................................................... 20
Revision History ......................................................................................................................................................................... 21
Compliance Declaration Disclaimer ...................................................................................................................................................... 22
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ICS-41352
SPECIFICATIONS
TABLE 1. ACOUSTICAL/ELECTRICAL CHARACTERISTICS – GENERAL
TA = 25°C, VDD = 1.8V to 3.3V, SCK = 2.4 MHz, CLOAD = 30 pF unless otherwise noted. Typical specifications are not guaranteed.
PARAMETER
PERFORMANCE
Directionality
Output Polarity
Supply Voltage (VDD)
Sleep Mode Current (IS)
CONDITIONS
MIN
TYP
MAX
UNITS
NOTES
Omni
Input acoustic pressure vs. output
data
Non-Inverted
1.65
3.63
SCK < 200 kHz
20
V
µA
TABLE 2. ACOUSTICAL/ELECTRICAL CHARACTERISTICS – ULTRASONIC MODE
TA = 25°C, VDD = 1.8V to 3.3V, SCK = 4.8 MHz, 25× decimation, CLOAD = 30 pF unless otherwise noted. Typical specifications are not
guaranteed.
PARAMETER
Sensitivity
Signal-to-Noise Ratio (SNR)
Equivalent Input Noise (EIN)
Dynamic Range
Total Harmonic Distortion (THD)
Power Supply Rejection (PSR)
Power Supply Rejection—Swept Sine
Acoustic Overload Point
Supply Current (IS)
CONDITIONS
1 kHz, 94 dB SPL
20 kHz bandwidth, A-weighted
20 kHz bandwidth, A-weighted
Derived from EIN and acoustic
overload point
105 dB SPL
217 Hz, 100 mV p-p square wave
superimposed on VDD = 1.8V, Aweighted
1 kHz sine wave
10% THD
VDD = 1.8V, no load
MIN
−27
TYP
−26
64
30
MAX
−25
90
0.2
UNITS
dB FS
dBA
dBA SPL
NOTES
1, 2
dB
1
%
−94
dB FS
−104
120
550
dB FS
dB SPL
µA
600
Note 1: Sensitivity is relative to the RMS level of a sine wave with positive amplitude equal to 100% 1s density and negative amplitude equal to 0% 1s density.
Note 2: The sensitivity shall not deviate more than 1.0 dB from its initial value after reliability tests.
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Revision: 1.0
ICS-41352
TABLE 3. ACOUSTICAL/ELECTRICAL CHARACTERISTICS – STANDARD MODE
TA = 25°C, VDD = 1.8V to 3.3V, SCK = 2.4 MHz, 50× decimation, CLOAD = 30 pF unless otherwise noted. Typical specifications are not
guaranteed.
PARAMETER
Sensitivity
Signal-to-Noise Ratio (SNR)
Equivalent Input Noise (EIN)
Acoustic Dynamic Range
Digital Dynamic Range
Total Harmonic Distortion (THD)
Power Supply Rejection (PSR)
Power Supply Rejection—Swept Sine
Acoustic Overload Point
Supply Current (IS)
CONDITIONS
1 kHz, 94 dB SPL
20 kHz bandwidth, A-weighted
20 kHz bandwidth, A-weighted
Derived from EIN and acoustic
overload point
Derived from EIN and full-scale
acoustic level
105 dB SPL
217 Hz, 100 mV p-p square wave
superimposed on VDD = 1.8V, Aweighted
1 kHz sine wave
10% THD
VDD = 1.8V, no load
MIN
−27
TYP
−26
64
30
MAX
−25
UNITS
dB FS
dBA
dBA SPL
90
dB
90
dB
0.2
1
%
−97
dB FS
−104
120
430
dB FS
dB SPL
µA
500
NOTES
1, 2
Note 1: Sensitivity is relative to the RMS level of a sine wave with positive amplitude equal to 100% 1s density and negative amplitude equal to 0% 1s density.
Note 2: The sensitivity shall not deviate more than 1.0 dB from its initial value after reliability tests.
TABLE 4. ACOUSTICAL/ELECTRICAL CHARACTERISTICS – LOW-POWER MODE
TA = 25°C, VDD = 1.8V to 3.3V, SCK = 768 kHz, 50× decimation, CLOAD = 30 pF unless otherwise noted. Typical specifications are not
guaranteed.
PARAMETER
Sensitivity
Signal-to-Noise Ratio (SNR)
Equivalent Input Noise (EIN)
Dynamic Range
Total Harmonic Distortion (THD)
Power Supply Rejection (PSR)
Power Supply Rejection—Swept Sine
Acoustic Overload Point
Supply Current (IS)
CONDITIONS
1 kHz, 94 dB SPL
8 kHz bandwidth, A-weighted
8 kHz bandwidth, A-weighted
Derived from EIN and acoustic
overload point
105 dB SPL
217 Hz, 100 mV p-p square wave
superimposed on VDD = 1.8V, Aweighted
1 kHz sine wave
10% THD
VDD = 1.8V, no load
MIN
−27
TYP
−26
63
31
MAX
−25
89
0.2
UNITS
dB FS
dBA
dBA SPL
NOTES
1, 2
dB
1
%
−97
dB FS
−98
120
185
dB FS
dB SPL
µA
225
Note 1: Sensitivity is relative to the RMS level of a sine wave with positive amplitude equal to 100% 1s density and negative amplitude equal to 0% 1s density.
Note 2: The sensitivity shall not deviate more than 1.0 dB from its initial value after reliability tests.
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ICS-41352
TABLE 5. DIGITAL INPUT/OUTPUT CHARACTERISTICS
TA = 25°C, 1.8V < VDD < 3.3V, unless otherwise noted.
PARAMETER
CONDITIONS
MIN
Input Voltage High (VIH)
TYP
MAX
UNITS
0.65 x VDD
V
Input Voltage Low (VIL)
0.35 x VDD
Output Voltage High (VOH)
ILOAD = 0.5 mA
Output Voltage Low (VOL)
ILOAD = 0.5 mA
Output DC Offset
Latency
Percent of full scale
NOTES
0.7 x VDD
V
V
VDD
0
0.3 x VDD
3
400
kHz, output within 0.5 dB of final
sensitivity, power on
Between Low-Power and Standard Modes
Between Low-Power and Ultrasonic Modes
Wake-Up Time
Switching time
Switching time
INPUT
tCLKIN
Input clock period
208
Sleep Mode
Clock Frequency (CLK)
Clock Duty Cycle
tRISE
tFALL
OUTPUT
T1OUTEN
T1OUTDIS
T2OUTEN
T2OUTDIS
Note 1: Guaranteed by design
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ns
ns
ns
ns
1
1
ICS-41352
TIMING DIAGRAM
tCLKIN
CLK
tFALL
tRISE
t1OUTEN
t1OUTDIS
DATA1
t2OUTDIS
DATA2
t2OUTEN
Figure 1. Pulse Density Modulated Output Timing
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ICS-41352
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 7. ABSOLUTE MAXIMUM RATINGS
PARAMETER
RATING
−0.3V to +3.63V
Supply Voltage (VDD)
Digital Pin Input Voltage
Sound Pressure Level
−0.3V to VDD + 0.3V or 3.63V, whichever is less
160 dB
Mechanical Shock
10,000g
Vibration
Per MIL-STD-883 Method 2007, Test Condition B
Temperature Range
Biased
Storage
−40°C to +85°C
−55°C to +150°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.
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Document Number: DS-000048
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ICS-41352
SOLDERING PROFILE
CRITICAL ZONE
TL TO TP
tP
TP
TEMPERATURE
RAMP-UP
TL
tL
TSMAX
TSMIN
tS
RAMP-DOWN
PREHEAT
t25°C TO PEAK TEMPERATURE
TIME
Figure 2. Recommended Soldering Profile Limits
TABLE 8. RECOMMENDED SOLDERING PROFILE*
PROFILE FEATURE
Average Ramp Rate (TL to TP)
Sn63/Pb37
1.25°C/sec max
Pb-Free
1.25°C/sec max
100°C
100°C
150°C
200°C
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)
Peak Temperature (TP)
183°C
217°C
215°C +3°C/−3°C
260°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 min max
5 min max
Preheat
Minimum Temperature
(TSMIN)
Minimum Temperature
(TSMIN)
Time (TSMIN to TSMAX), tS
*The reflow profile in
Table 8 is recommended for board manufacturing with InvenSense MEMS microphones. All microphones are also compatible with the J-STD-020 profile
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ICS-41352
PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS
Figure 3. Pin Configuration (Top View, Terminal Side Down)
TABLE 9. PIN FUNCTION DESCRIPTIONS
PIN
NAME
FUNCTION
1
DATA
Digital Output Signal (DATA1 or DATA2)
2
SELECT
Left Channel or Right Channel Select:
DATA 1 (right): SELECT tied to GND
DATA 2 (left): SELECT tied to VDD
3
GND
Ground
4
CLK
Clock Input to Microphone
5
VDD
Power Supply. For best performance and to avoid potential parasitic artifacts, place a 0.1 µF (100 nF)
ceramic type X7R capacitor between Pin 5 (VDD) and ground. Place the capacitor as close to Pin 5 as
possible.
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ICS-41352
TYPICAL PERFORMANCE CHARACTERISTICS
Low Power Mode
20
10
Standard Mode
10
THD+N (%)
NORMALIZED AMPLITUDE (dB)
30
0
1
-10
-20
0.1
10
100
1000
10000
90
FREQUENCY (Hz)
120
130
Figure 5. THD + N vs. Input Level
0
0
OUTPUT AMPLITUDE (dB FS)
-20
PSR (dB FS)
110
INPUT AMPLITUDE (dB SPL)
Figure 4. Typical Frequency Response
-40
-60
-80
-100
-120
-10
-20
-30
-40
100
1000
10000
90
FREQUENCY (Hz)
100
110
120
INPUT AMPLITUDE (dB SPL)
Figure 6. Power Supply Rejection (PSR) vs. Frequency
Figure 7. Linearity
25
70
20
60
15
SNR re: 80 dB SPL (dB)
NORMALIZED AMPLITUDE (dB RE: 1 kHz)
100
10
5
0
-5
-10
-15
50
40
30
20
10
-20
-25
10,000
0
30,000
50,000
70,000
FREQUENCY (Hz)
CENTER FREQUENCY OF 5 kHz BAND (Hz)
Figure 8. Typical Ultrasonic Frequency Response
Figure 9. Typical Ultrasonic SNR
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ICS-41352
THEORY OF OPERATION
PDM DATA FORMAT
The output from the DATA pin of the ICS-41352 is in pulse density modulated (PDM) format. This data is the 1-bit output of a fourthorder Σ-Δ modulator. The data is encoded so that the left channel is clocked on the falling edge of CLK, and the right channel is clocked
on the rising edge of CLK. After driving the DATA signal high or low in the appropriate half frame of the CLK signal, the DATA driver of
the microphone tristates. In this way, two microphones, one set to the left channel and the other to the right, can drive a single DATA
line. See Figure 1 for a timing diagram of the PDM data format; the DATA1 and DATA2 lines shown in this figure are two halves of the
single physical DATA signal. Figure 10 shows a diagram of the two stereo channels sharing a common DATA line.
CLK
DATA2 (L)
DATA
DATA1 (R)
DATA2 (L)
DATA1 (R)
Figure 10. Stereo PDM Format
If only one microphone is connected to the DATA signal, the output is only clocked on a single edge (Figure 11). For example, a left
channel microphone is never clocked on the rising edge of CLK. In a single microphone application, each bit of the DATA signal is
typically held for the full CLK period until the next transition because the leakage of the DATA line is not enough to discharge the line
while the driver is tristated.
CLK
DATA
DATA1 (R)
DATA1 (R)
DATA1 (R)
Figure 11. Mono PDM Format
See Table 10 for the channel assignments according to the logic level on the SELECT pin.
TABLE 10. ICS-41352 CHANNEL SETTING
SELECT Pin Setting
Low (tie to GND)
High (tie to VDD)
Channel
Right (DATA1)
Left (DATA2)
For PDM data, the density of the pulses indicates the signal amplitude. A high density of high pulses indicates a signal near positive
full scale, and a high density of low pulses indicates a signal near negative full scale. A perfect zero (dc) audio signal shows an
alternating pattern of high and low pulses.
The output PDM data signal has a small dc offset of about 3% of full scale. A high-pass filter in the codec that is connected to the digital
microphone and does not affect the performance of the microphone typically removes this dc signal.
PDM MICROPHONE SENSITIVITY
The sensitivity of a PDM output microphone is specified with the unit dB FS (decibels relative to digital full scale). A 0 dB FS sine
wave is defined as a signal whose peak just touches the full-scale code of the digital word (see Figure 12). This measurement
convention also means that signals with a different crest factor may have an RMS level higher than 0 dB FS. For example, a full-scale
square wave has an RMS level of 3 dB FS.
This definition of a 0 dB FS signal must be understood when measuring the sensitivity of the ICS-41352. A 1 kHz sine wave at a
94 dB SPL acoustic input to the ICS-41352 results in an output signal with a −26 dB FS level. The output digital word peaks at
−26 dB below the digital full-scale level. A common misunderstanding is that the output has an RMS level of −29 dB FS; however, this is
not true because of the definition of the 0 dB FS sine wave.
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ICS-41352
1.0
0.8
DIGITAL AMPLITUDE (D)
0.6
0.4
0.2
0
–0.2
–0.4
–0.6
–0.8
–1.0
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
TIME (ms)
Figure 12. 1 kHz, 0 dB FS Sine Wave
There is not a commonly accepted unit of measurement to express the instantaneous level, as opposed to the RMS level of the
signal, of a digital signal output from the microphone. Some measurement systems express the instantaneous level of an individual
sample in units of D, where 1.0 D is digital full scale. In this case, a −26 dB FS sine wave has peaks at 0.05 D.
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ICS-41352
APPLICATIONS INFORMATION
LOW POWER MODE
Low Power Mode (LPM) enables the ICS-41352 to be used in an AlwaysOn listening mode for keyword spotting and ambient sound
analysis. The ICS-41352 will enter LPM when the frequency of SCK is between 400 and 800 kHz. In this mode, the microphone
consumes only 185 µA while retaining high electro-acoustic performance.
When one microphone is in LPM for AlwaysOn listening, a second microphone sharing the same data line may be powered down. In
this case, where one microphone is powered up and another is powered down by disabling the VDD supply or in sleep mode by
reducing the frequency of a separate clock source, the disabled microphone does not present a load to the signal on the LPM
microphone’s DATA pin.
DYNAMIC RANGE CONSIDERATIONS
The full-scale digital output (0 dB FS) of the ICS-41352 is mapped to an acoustic input of 120 dB SPL. The microphone clips (THD =
10%) at 120 dB SPL (see Figure 5); however, it continues to output an increasingly distorted signal above that point. The peak output
level, which is controlled by the modulator, limits at 0 dB FS (see Figure 7).
To fully use the 90 dB dynamic range of the output data of the ICS-41352 in a design, the digital signal processor (DSP), analog-to-digital
converter (ADC), or codec circuit following it must be chosen carefully. The decimation filter that inputs the PDM signal from the ICS41352 must have a dynamic range sufficiently better than the dynamic range of the microphone so that the overall noise
performance of the system is not degraded. If the decimation filter has a dynamic range of 10 dB better than the microphone, the
overall system noise only degrades by 0.4 dB. This 100 dB filter dynamic range requires the filter to have at least 17-bit resolution.
CONNECTING PDM MICROPHONES
A PDM output microphone is typically connected to a codec with a dedicated PDM input. This codec separately decodes the left and right
channels and filters the high sample rate modulated data back to the audio frequency band. This codec also generates the clock for the
PDM microphones or is synchronous with the source that is generating the clock. Figure 13 and Figure 14 show mono and stereo
connections of the ICS-41352 to a codec. The mono connection shows an ICS-41352 set to output data on the right channel. To output
on the left channel, tie the SELECT pin to VDD instead of tying it to GND.
1.8V TO 3.3V
0.1µF
VDD
ICS-41352
SELECT
CODEC
CLOCK OUTPUT
CLK
DATA
DATA INPUT
GND
Figure 13. Mono PDM Microphone (Right Channel) Connection to Codec
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ICS-41352
1.8V TO 3.3V
0.1µF
VDD
CODEC
CLK
ICS-41352
SELECT
CLOCK OUTPUT
DATA
DATA INPUT
GND
1.8V TO 3.3V
0.1µF
VDD
ICS-41352
SELECT
CLK
DATA
GND
Figure 14. Stereo PDM Microphone Connection to Codec
Decouple the VDD pin of the ICS-41352 to GND with a 0.1 µF capacitor. Place this capacitor as close to VDD as the printed circuit board
(PCB) layout allows.
Do not use a pull-up or pull-down resistor on the PDM data signal line because it can pull the signal to an incorrect state during the period
that the signal line is tristated.
The DATA signal does not need to be buffered in normal use when the ICS-41352 microphone(s) is placed close to the codec on the PCB. If
the DATA signal must be driven over a long cable (>15 cm) or other large capacitive load, a digital buffer may be required. Only use a signal
buffer on the DATA line when one microphone is in use or after the point where two microphones are connected (see Figure 15). The
DATA output of each microphone in a stereo configuration cannot be individually buffered because the two buffer outputs cannot
drive a single signal line. If a buffer is used, take care to select one with low propagation delay so that the timing of the data
connected to the codec is not corrupted.
CODEC
ICS-41352
CLK
CLOCK OUTPUT
DATA
DATA INPUT
ICS-41352
CLK
DATA
Figure 15. Buffered Connections Between Stereo ICS-41352s and a Codec
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ICS-41352
When long wires are used to connect the codec to the ICS-41352, a source termination resistor can be used on the clock output of the
codec instead of a buffer to minimize signal overshoot or ringing. Match the value of this resistor to the characteristic impedance of
the CLK trace on the PCB. Depending on the drive capability of the codec clock output, a buffer may still be needed, as shown in Figure
15.
ULTRASOUND APPLICATIONS
In its Ultrasonic Mode, the ICS-41352 functions as a low-noise ultrasonic sensor, as well as an audio band sensor. The microphone’s
ultrasonic performance will depend on the clock frequency, the low pass decimation filter, the strength of the ultrasonic signal being
sensed, and the design of the acoustic port that is coupled to the microphone. The acoustic port design is especially important at
higher frequencies, because the size of the port itself is on the order of ¼ the wavelength of sound and the acoustic mass loading will
be significant. These will both contribute to the port having a considerable effect on the acoustic system’s response.
SLEEP MODE
The microphone enters sleep mode when the clock frequency falls below 200 kHz. In this mode, the microphone data output is in a high
impedance state. The current consumption in sleep mode is less than 20 µA.
The ICS-41352 enters sleep mode within 1 ms of the clock frequency falling below 200 kHz. The microphone wakes up from sleep
mode and begins to output data within 20 ms of when the clock becomes active.
START-UP TIME
The start-up time of the ICS-41352 is less than 20 ms. The PDM data from the microphone is valid to be used as soon as the data is
being output.
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ICS-41352
SUPPORTING DOCUMENTS
For additional information, see the following documents.
APPLICATION NOTES
AN-000048, PDM Digital Output MEMS Microphone Flex Evaluation Board User Guide
AN-100, MEMS Microphone Handling and Assembly Guide
AN-1003: Recommendations for Mounting and Connecting the Invensense, Bottom-Ported MEMS Microphones
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
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ICS-41352
PCB DESIGN AND LAND PATTERN LAYOUT
The recommended PCB land pattern for the ICS-41352 is a 1:1 ratio of the solder pads on the microphone package, as shown in Figure
16. Avoid applying solder paste to the sound hole in the PCB. A suggested solder paste stencil pattern layout is shown in Figure 17.
The response of the ICS-41352 is not affected by the PCB hole size as long as the hole is not smaller than the sound port of the
microphone (0.375 mm in diameter). A 0.5 mm to 1 mm diameter for the hole is recommended. Take care to align the hole in the
microphone package with the hole in the PCB. The exact degree of the alignment does not affect the microphone performance as long
as the holes are not partially or completely blocked.
0.522x0.725(4X)
Ø1.625
Ø1.025
1.675
0.838
0.822
1.252
Figure 16. Recommended PCB Land Pattern Layout
0.422x0.625(4X)
Ø1.625
Ø1.125
1.675
0.1(4x)
0.822
1.252
Figure 17. Suggested Solder Paste Stencil Pattern Layout
PCB MATERIAL AND THICKNESS
The audio performance of the ICS-41352 is not affected by PCB thickness. The ICS-41352 can be mounted on either a rigid or flexible
PCB. A flexible PCB with the microphone can be attached directly to the device housing with an adhesive layer. This mounting
method offers a reliable seal around the sound port while providing the shortest acoustic path for good sound quality.
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Document Number: DS-000048
Revision: 1.0
ICS-41352
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 2 and
Table 8.
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.
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Document Number: DS-000048
Revision: 1.0
ICS-41352
OUTLINE DIMENSIONS
d
3.50
(4X)
0.10
0.522X0.725 (4x)
j 0.10 m C A B
A
PIN 1
CORNER
0.125
PIN 1
CORNER
0.82
Ø1.625
Ø1.025
(2.45)
2.65
2.650
1
2
5
4
Ø0.375
0.950
1.675
3
0.300
0.125
B
(3.30)
1.040
1.513
3.500
BOTTOM VIEW
TOP VIEW
f
0.10 C
0.98
SIDE VIEW
(0.254)
C
Figure 18. 5-Terminal Chip Array Small Outline No Lead Cavity [LGA_CAV]
3.5 mm × 2.65 mm × 0.98 mm Body
Dimensions shown in millimeters
Dimension tolerance is ±0.15 mm unless otherwise specified
PART NUMBER
PIN 1 INDICATION
352
YYXXX
LOT TRACEABILITY CODE
DATE CODE
Figure 19. Package Marking Specification (Top View)
ORDERING GUIDE
PART
ICS-41352
TEMP RANGE
−40°C to +85°C
PACKAGE
5-Terminal LGA_CAV
QUANTITY
5,000
EV_ICS-41352-FX
—
Evaluation Board
—
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Document Number: DS-000048
Revision: 1.0
PACKAGING
13” Tape and Reel
1.33
ICS-41352
REVISION HISTORY
REVISION DATE
REVISION
DESCRIPTION
9/30/2016
1.0
Initial version
Page 21 of 22
Document Number: DS-000048
Revision: 1.0
ICS-41352
COMPLIANCE DECLARATION DISCLAIMER
InvenSense believes the environmental and other compliance information given in this document to be correct but cannot
guarantee accuracy or completeness. Conformity documents substantiating the specifications and component characteristics 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 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.
©2016 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.
©2016 InvenSense, Inc. All rights reserved.
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Document Number: DS-000048
Revision: 1.0
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