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Bottom Port PDM Low‐Power Multi‐Mode Microphone With High AOP Mode InvenSense, Inc. reserves the right to change the detail specifications as may be required to permit improvements in the design of its products. InvenSense Inc. 1745 Technology Drive, San Jose, CA 95110 U.S.A +1(408) 988–7339 www.invensense.com Document Number: DS‐000357 Revision: 1.0 Rev Date: 4/15/2020 GENERAL DESCRIPTION The T3902 is a low‐power, low‐noise digital MEMS microphone in a small package. The T3902 consists of a MEMS microphone element and an impedance converter amplifier followed by a fourth‐order Σ‐Δ modulator. The pulse density modulated (PDM) interface allows two microphones to be time multiplexed on a data line using a single clock. The T3902 has multiple modes of operation: High Performance, Low Power (AlwaysOn), Standard and Sleep. The T3902 has low power and high SNR in all operational modes. It has 126 dB SPL AOP in High Performance mode, and 120 dB SPL AOP in Standard and Low‐Power modes. The T3902 is available in a small 3.5 × 2.65 × 0.98 mm surface‐mount package. It is reflow solder compatible with no sensitivity degradation.
APPLICATIONS
Smartphones Microphone Arrays Tablets Cameras Bluetooth Headsets Notebook PCs Security and Surveillance
FEATURES
SPEC LOW‐POWER MODE STANDARD MODE HIGH PERFORMANCE MODE Sensitivity −26 dB FS ±1 dB − 26 dB FS ±1 dB − 32 dB FS ±1 dB SNR 63 dBA 64.5 dBA 64 dBA Current 185 µA 430 µA 650 µA AOP 120 dB SPL 120 dB SPL 126 dB SPL Clock 400 – 800 kHz 1.0 – 3.3 MHz 4.1 – 4.8 MHz 3.5 × 2.65 × 0.98 mm surface‐mount package Low power: 185 µA in Low‐Power Mode Extended frequency response from 36 Hz to >20 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 FUNCTIONAL BLOCK DIAGRAM
ORDERING INFORMATION
MMICT3902‐00‐012 −40°C to +85°C 13” Tape and Reel EV_T3902‐FX —
Document Number: DS‐000357 Revision: 1.0
TABLE 1. ACOUSTICAL/ELECTRICAL CHARACTERISTICS – GENERAL Output Polarity Input acoustic pressure vs. TABLE 2. ACOUSTICAL/ELECTRICAL CHARACTERISTICS – HIGH‐PERFORMANCE MODE 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 3. ACOUSTICAL/ELECTRICAL CHARACTERISTICS – STANDARD MODE 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 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 5. DIGITAL INPUT/OUTPUT CHARACTERISTICS TA = 25°C, 1.8 V < VDD < 3.3 V, unless otherwise noted. TABLE 6. PDM DIGITAL INPUT/OUTPUT TA = 25°C, 1.8 V < VDD < 3.3 V, unless otherwise noted.
Figure 1. Pulse Density Modulated Output Timing
extended periods may affect device reliability. TABLE 7. ABSOLUTE MAXIMUM RATINGS ESD (electrostatic discharge) sensitive device. devices subjected to high energy ESD.
Figure 2. Recommended Soldering Profile Limits TABLE 8. RECOMMENDED SOLDERING PROFILE*
Figure 3. Pin Configuration (Top View, Terminal Side Down) TABLE 9. PIN FUNCTION DESCRIPTIONS
1 DATA Digital Output Signal (DATA1 or DATA2)
2 SELECT
3 GND Ground
4 CLK Clock Input to Microphone
5 VDD
Figure 10. 1 kHz, 0 dB FS Sine Wave 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.
only 185 µA while retaining high electro‐acoustic performance. that point. The peak output level, which is controlled by the modulator, limits at 0 dB FS (see Figure 7). noise only degrades by 0.4 dB. This 106 dB filter dynamic range requires the filter to have at least 18 bit resolution. left channel, tie the SELECT pin to VDD instead of tying it to GND. Figure 11. Mono PDM Microphone (Right Channel) Connection to Codec
Document Number: DS‐000357 Revision: 1.0 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 13. 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 T3902 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. In sleep mode: If the SELECT signal is logic high, the DATA pin will be pulled low to GND. If the SELECT signal is logic low, the DATA pin will be high impedance (floating). CLK SELECT DATA <200kHz or float VDD GND <200kHz or float GND HiZ START‐UP TIME The start‐up time of the T3902 is less than 20 ms. The PDM data from the microphone is valid to be used as soon as the data is being output.
Document Number: DS‐000357 Revision: 1.0 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
Document Number: DS‐000357 Revision: 1.0 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.
Document Number: DS‐000357 Revision: 1.0
REVISION HISTORY
REVISION DATE REVISION DESCRIPTION 12/16/2019 0.1 Initial version 2/12/2020 0.2 Updated Package Marking Specification 4/15/2020 1.0 Initial release
Document Number: DS‐000357 Revision: 1.0 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, Inc. (“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. ©2019 InvenSense. All rights reserved. InvenSense, MotionTracking, MotionProcessing, MotionProcessor, MotionFusion, MotionApps, DMP, AAR, and the InvenSense logo are trademarks of InvenSense, Inc. The InvenSense logo is a trademark of InvenSense Corporation. Other company and product names may be trademarks of the respective companies with which they are associated. ©2019 InvenSense. All rights reserved.