TDK T3903 User manual

T3903
Bottom Port PDM Digital Output Multi-Mode Microphone
This document contains information on a preproduction
product. Specifications and information herein are
subject to change without notice
TDK Corporation
1745 Technology Drive, San Jose, CA 95110 U.S.A
[phone]
www.tdk.com
Document Number: DS-000358
Revision: 1.0
Release Date: 5/5/2020
GENERAL DESCRIPTION
The T3903 is a multi-mode, low noise digital MEMS
microphone in a small package. The T3903 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 T3903 has multiple modes of operation: High Quality,
Low-Power (AlwaysOn), and Sleep. The T3903 has high SNR in
all operational modes. It has 133 dB SPL AOP in High Quality
Mode and 120 dB SPL AOP in Low-Power mode.
The T3903 is available in a standard 3.5 × 2.65 × 0.98 mm
surface-mount package. It is reflow solder compatible with
no sensitivity degradation.
FUNCTIONAL BLOCK DIAGRAM
APPLICATIONS
•Smartphones
•Microphone Arrays
•Tablet Computers
•Cameras
FEATURES
SPEC
HIGH QUALITY MODE
LOW-POWER MODE
Sensitivity
−37 dB FS ±1 dB
−26 dB FS ±1 dB
SNR
66 dBA
63 dBA
Current
590 µA
220 µA
AOP
133 dB SPL
120 dB SPL
Clock
2.0 MHz to 3.3 MHz
400 kHz to 800 kHz
•3.5 × 2.65 × 0.98 mm surface-mount package
•Extended frequency response from 40 Hz to >20 kHz
•Sleep Mode: 9 µA
•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
PART
TEMP RANGE
PACKAGING
MMICT3903-00-012
−40°C to +85°C
13” Tape and Reel
EV_T3903-FX
—
ICS-51360
ADC
POWER
MANAGEMENT
CLK
DATA
VDD
GND
PDM
MODULATOR
CHANNEL
SELECT
SELECT
T3903

T3903
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Document Number: DS-000358
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TABLE OF CONTENTS
General Description ..................................................................................................................................................................... 1
Functional Block Diagram ............................................................................................................................................................ 1
Applications ................................................................................................................................................................................. 1
Features ....................................................................................................................................................................................... 1
Ordering Information................................................................................................................................................................... 1
Table of Contents.................................................................................................................................................................................... 2
Specifications .......................................................................................................................................................................................... 4
Table 1. Acoustical/Electrical Characteristics – General.............................................................................................................. 4
Table 2. Acoustical/Electrical Characteristics – High Quality Mode ............................................................................................ 4
Table 3. Acoustical/Electrical Characteristics – Low-Power Mode.............................................................................................. 5
Table 4. Digital Input/Output Characteristics .............................................................................................................................. 5
Table 5. PDM Digital Input/Output.............................................................................................................................................. 6
Timing Diagram............................................................................................................................................................................ 6
Absolute Maximum Ratings.................................................................................................................................................................... 7
Table 6. Absolute Maximum Ratings ........................................................................................................................................... 7
ESD Caution ................................................................................................................................................................................. 7
Soldering Profile........................................................................................................................................................................... 8
Table 7. Recommended Soldering Profile*.................................................................................................................................. 8
Pin Configurations And Function Descriptions ....................................................................................................................................... 9
Table 8. Pin Function Descriptions............................................................................................................................................... 9
Typical Performance Characteristics..................................................................................................................................................... 10
Theory Of Operation............................................................................................................................................................................. 11
PDM Data Format ...................................................................................................................................................................... 11
Table 9. T3903 Channel Setting ................................................................................................................................................. 11
PDM Microphone Sensitivity ..................................................................................................................................................... 11
Applications Information ...................................................................................................................................................................... 13
Low-Power Mode....................................................................................................................................................................... 13
Dynamic Range Considerations ................................................................................................................................................. 13
Connecting PDM Microphones.................................................................................................................................................. 13
Sleep Mode................................................................................................................................................................................ 15
Start-Up Time............................................................................................................................................................................. 15
Supporting Documents ......................................................................................................................................................................... 16
Application Notes – General ...................................................................................................................................................... 16
PCB Design And Land Pattern Layout ................................................................................................................................................... 17
PCB Material And Thickness ...................................................................................................................................................... 17
Handling Instructions............................................................................................................................................................................ 18
Pick And Place Equipment ......................................................................................................................................................... 18
Reflow Solder............................................................................................................................................................................. 18

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Document Number: DS-000358
Revision: 1.0
Board Wash ............................................................................................................................................................................... 18
Outline Dimensions............................................................................................................................................................................... 19
Ordering Guide .......................................................................................................................................................................... 19
Revision History ......................................................................................................................................................................... 20
Compliance Declaration Disclaimer ...................................................................................................................................................... 21

T3903
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Document Number: DS-000358
Revision: 1.0
SPECIFICATIONS
TABLE 1. ACOUSTICAL/ELECTRICAL CHARACTERISTICS – GENERAL
TA= 25°C, VDD = 1.8 V to 3.3 V, SCK = 2.4 MHz, CLOAD = 30 pF unless otherwise noted. Typical specifications are not guaranteed.
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
NOTES
PERFORMANCE
Directionality
Omni
Output Polarity
Input acoustic pressure vs. output
data
Non-Inverted
Supply Voltage (VDD)
1.65
1.8
3.63
V
Sleep Mode Current (IS)
SCK < 200 kHz, VDD=1.8V
9
µA
1
Note 1: Sleep Mode current is not specified at 3.3V
TABLE 2. ACOUSTICAL/ELECTRICAL CHARACTERISTICS – HIGH QUALITY MODE
TA= 25°C, VDD = 1.8 V to 3.3 V, SCK = 2.4 MHz, CLOAD = 30 pF unless otherwise noted. Typical specifications are not guaranteed.
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
NOTES
Sensitivity
1 kHz, 94 dB SPL
−38
−37
−36
dB FS
2
Signal-to-Noise Ratio (SNR)
20 kHz bandwidth, A-weighted
66
dBA
Equivalent Input Noise (EIN)
20 kHz bandwidth, A-weighted
28
dBA SPL
Acoustic Dynamic Range
Derived from EIN and acoustic
overload point
105 dB
Total Harmonic Distortion (THD)
94 dB SPL
0.1
%
Power Supply Rejection (PSR)
20 Hz, 100 mVpp applied to V
DD
1 kHz, 100 mVpp applied to VDD
5 kHz, 100 mVpp applied to VDD
10 kHz, 100 mVpp applied to VDD
20 kHz, 100 mVpp applied to VDD
-86
-109
-98
-96
-81
dB FS(A)
Power Supply Rejection (PSR)
217 Hz, 100 mV p-p square wave
superimposed on VDD = 1.8 V, A-
weighted
-105 dB FS (A)
Power Supply Rejection—Swept Sine
1 kHz sine wave
-109
dB FS
Acoustic Overload Point
10% THD
133
dB SPL
Supply Current (IS)
VDD = 1.8 V, no load
590
µA
Note 2: 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.

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Document Number: DS-000358
Revision: 1.0
TABLE 3. ACOUSTICAL/ELECTRICAL CHARACTERISTICS – LOW-POWER MODE
TA= 25°C, VDD = 1.8 V to 3.3 V, SCK = 768 kHz, CLOAD = 30 pF unless otherwise noted. Typical specifications are not guaranteed.
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
NOTES
Sensitivity
1 kHz, 94 dB SPL
−27
−26
−25
dB FS
3
Signal-to-Noise Ratio (SNR)
8 kHz bandwidth, A-weighted
63
dBA
Equivalent Input Noise (EIN)
8 kHz bandwidth, A-weighted
31
dBA SPL
Acoustic Dynamic Range
Derived from EIN and acoustic overload point
89 dB
Total Harmonic Distortion (THD)
105 dB SPL
0.15
%
Power Supply Rejection (PSR)
217 Hz, 100 mV p-p square wave superimposed on
VDD = 1.8 V, A-weighted
−95 dB FS
Power Supply Rejection—Swept Sine
1 kHz sine wave
−99
dB FS
Acoustic Overload Point
10% THD
120
dB SPL
Supply Current (IS)
VDD = 1.8 V, no load
220
µA
Note 3: 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.
TABLE 4. DIGITAL INPUT/OUTPUT CHARACTERISTICS
TA= 25°C, 1.8 V < VDD < 3.3 V, unless otherwise noted.
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
NOTES
Input Voltage High (VIH) 0.65 × VDD V
Input Voltage Low (VIL) 0.35 × VDD V
Output Voltage High (V
OH
)
ILOAD = 0.5 mA 0.7 × VDD VDD
V
Output Voltage Low (V
OL
)
ILOAD = 0.5 mA 0 0.3 × VDD
V
Output DC Offset
Percent of full scale
3 %

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Document Number: DS-000358
Revision: 1.0
TABLE 5. PDM DIGITAL INPUT/OUTPUT
TA= 25°C, 1.8 V < VDD < 3.3 V , unless otherwise noted.
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
NOTES
MODE SWITCHING
Sleep Time
Time from f
CLK
falling <200 kHz
1
ms
Wake-Up Time
High Quality mode, Sleep Mode to f
CLK
>1.2
MHz, output within 0.5 dB of final sensitivity,
power on
7 ms
Wake-Up Time
Low-Power Mode, Sleep Mode to f
CLK
>400
kHz, output within 0.5 dB of final sensitivity,
power on
7 ms
Switching time
Between Low-Power and High Quality Mode
7
ms
INPUT
tCLKIN Input clock period
303
2500
ns
Clock Frequency (CLK)
Sleep Mode
200
kHz
Low-Power Mode
400
800
kHz
High Quality Mode
2.0
3.3
MHz
Clock Duty Cycle fCLK <3.3 MHz
45
55
%
tRISE CLK rise time (10% to 90% level)
25
ns 4
tFALL CLK fall time (90% to 10% level)
25
ns 4
OUTPUT
t1OUTEN
DATA1 (right) driven after falling clock edge
30
ns
t1OUTDIS
DATA1 (right) disabled after rising clock edge
5
18
ns
t2OUTEN
DATA2 (left) driven after rising clock edge
30
ns
t2OUTDIS
DATA2 (left) disabled after falling clock edge
5
18
ns
Note 4: Guaranteed by design
TIMING DIAGRAM
Figure 1. Pulse Density Modulated Output Timing
tCLKIN
CLK
DATA2
DATA1
t2OUTDIS
t1OUTDIS
t2OUTEN
t1OUTEN
tRISE
tFALL

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Document Number: DS-000358
Revision: 1.0
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 6. ABSOLUTE MAXIMUM RATINGS
PARAMETER
RATING
Supply Voltage (VDD)
−0.3 V to +3.63 V
Digital Pin Input Voltage
−0.3 V to VDD + 0.3 V or 3.63 V, whichever is less
Mechanical Shock
10,000 g
Vibration
Per MIL-STD-883 Method 2007, Test Condition B
Temperature Range
Operating
−40°C to +85°C
Storage
−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-000358
Revision: 1.0
SOLDERING PROFILE
Figure 2. Recommended Soldering Profile Limits
TABLE 7. 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
Maximum Temperature
(TSMAX)
150°C 200°C
Time (TSMIN to TSMAX), tS60 sec to 75 sec 60 sec to 75 sec
Ramp-Up Rate (TSMAX to TL) 1.25°C/sec 1.25°C/sec
Time Maintained Above Liquidous (tL) 45 sec to 75 sec ~50 sec
Liquidous Temperature (TL) 183°C 217°C
Peak Temperature (T
P
)
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
*The reflow profile in Table 7 is recommended for board manufacturing with TDK MEMS microphones. All microphones are also
compatible with the J-STD-020 profile
tP
tL
t25°C TO PEAK TEMPERATURE
tS
PREHEAT
CRITICALZONE
T
L
TO T
P
TEMPERATURE
TIME
RAMP-DOWN
RAMP-UP
T
SMIN
T
SMAX
T
P
T
L

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Document Number: DS-000358
Revision: 1.0
PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS
Figure 3. Pin Configuration (Top View, Terminal Side Down)
TABLE 8. 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. In this setting, SELECT should be tied to the same voltage
source as the VDD pin.
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.
DATA
VDD
GND
1
2
3
5
4
SELECT
CLK

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Document Number: DS-000358
Revision: 1.0
TYPICAL PERFORMANCE CHARACTERISTICS
Figure 4. Typical Audio Frequency Response, High Quality Mode
Figure 5. THD + N
Figure 6. Power Supply Rejection (PSR) vs. Frequency
Figure 7. Linearity
-20.0
-10.0
0.0
10.0
20.0
10 100 1000 10000
NORMALIZED AMPLITUDE (dB)
FREQUENCY (Hz)
0.01
0.10
1.00
10.00
90 100 110 120 130 140
THD+N (%)
INPUT AMPLITUDE (dB SPL)
High Quality Mode
Low Power Mode
-120.0
-100.0
-80.0
-60.0
-40.0
-20.0
0.0
100 1000 10000
PSRR (dB)
FREQUENCY (Hz)
High Quality Mode
Low Power Mode
-45.00
-40.00
-35.00
-30.00
-25.00
-20.00
-15.00
-10.00
-5.00
0.00
90 100 110 120 130 140
OUTPUT AMPLITUDE (dBFS)
INPUT AMPLITUDE (dB SPL)
High Quality Mode
Low Power Mode