INMP441 Omnidirectional Microphone with Bottom Port and I2S Digital Output APPLICATIONS GENERAL DESCRIPTION The INMP441 is a high-performance, low power, digital-output, omnidirectional MEMS microphone with a bottom port. The complete INMP441 solution consists of a MEMS sensor, signal conditioning, an analog-to-digital converter, anti-aliasing filters, power management, and an industry-standard 24-bit IS interface. The IS interface allows the INMP441 to connect directly to digital processors, such as DSPs and microcontrollers, without the need for an audio codec in the system. The INMP441 has a high SNR, making it an excellent choice for near field applications. The INMP441 has a flat wideband frequency response, resulting in natural sound with high intelligibility. The INMP441 is available in a thin 4.72 x 3.76 x 1 mm surfacemount package. It is reflow- solder compatible with no sensitivity degradation. The INMP441 is halide free. *Protected by U.S. Patents 7,449,356; 7,825,484; 7,885,423; and 7,961,897. Other patents are pending. FUNCTIONAL BLOCK DIAGRAM FILTER I2S SERIAL PORT L/R HARDWARE CONTROL CHIPEN GND GND GND VDD POWER MANAGEMENT * * Teleconferencing Systems Remote Controls Gaming Consoles Mobile Devices Laptops Tablets Security Systems FEATURES * * * * * * * * * Digital IS Interface with High-Precision 24-Bit Data High SNR of 61 dBA High Sensitivity of -26 dBFS Flat Frequency Response from 60 Hz to 15 kHz Low Current Consumption of 1.4 mA High PSR of -75 dBFS Small 4.72 x 3.76 x 1 mm Surface-Mount Package Compatible with Sn/Pb and Pb-Free Solder Processes RoHS/WEEE Compliant ORDERING INFORMATION PART INMP441 ADC * * * * * SCK SD WS INMP441ACEZ-R0* INMP441ACEZ-R7 EV_INMP441 EV_INMP441-FX * - 13" Tape and Reel -40C to +85C -40C to +85C -- -- - 7" Tape and reel to be discontinued. Contact sales@invensense.com for availability. BOTTOM InvenSense reserves the right to change the detail specifications as may be required to permit improvements in the design of its products. TEMP RANGE InvenSense Inc. 1745 Technology Drive, San Jose, CA 95110 U.S.A +1(408) 988-7339 www.invensense.com TOP Document Number: DS-INMP441-00 Revision: 1.0. Rev Date: 02/06/2014 INMP441 TABLE OF CONTENTS General Description ................................................................................................................................................... 1 Applications ............................................................................................................................................................... 1 Features ..................................................................................................................................................................... 1 Functional Block Diagram .......................................................................................................................................... 1 Ordering Information ................................................................................................................................................. 1 Specifications .................................................................................................................................................................... 4 Table 1. Electrical Characteristics .............................................................................................................................. 4 2 Table 2. I S Digital Input/Output Characteristics ....................................................................................................... 5 Table 3. Serial Data Port Timing Specifications.......................................................................................................... 5 Timing Diagram .......................................................................................................................................................... 5 Absolute Maximum Ratings .............................................................................................................................................. 6 Table 4. Absolute Maximum Ratings ......................................................................................................................... 6 ESD Caution ............................................................................................................................................................... 6 Soldering Profile......................................................................................................................................................... 7 Table 5. Recommended Soldering Profile.................................................................................................................. 7 Pin Configurations And Function Descriptions ................................................................................................................. 8 Table 6. Pin Function Descriptions............................................................................................................................. 8 Typical Performance Characteristics................................................................................................................................. 9 Theory of Operation ....................................................................................................................................................... 10 Understanding Sensitivity ........................................................................................................................................ 10 Power Management ................................................................................................................................................ 10 Normal Operation ................................................................................................................................................... 10 Standby Mode ......................................................................................................................................................... 10 Power-Down Mode ................................................................................................................................................. 10 Startup .................................................................................................................................................................... 10 IS Data Interface ..................................................................................................................................................... 11 Data Output Mode .................................................................................................................................................. 11 Data Word Length................................................................................................................................................... 11 Data-Word Format .................................................................................................................................................. 11 Digital Microphone Sensitivity ................................................................................................................................. 12 Synchronizing Microphones .................................................................................................................................... 13 Digital Filter Characteristics ..................................................................................................................................... 13 High-Pass Filter ........................................................................................................................................................ 13 Table 7. High Pass Filter Characteristics .................................................................................................................. 13 Low-Pass Filter ......................................................................................................................................................... 13 Applications Information ................................................................................................................................................ 14 Power-Supply Decoupling ........................................................................................................................................ 15 Document Number: DS-INMP441-00 Revision: 1.0. Page 2 of 21 INMP441 Supporting Documents ................................................................................................................................................... 16 Evaluation Board User Guide ................................................................................................................................... 16 Application Notes (Product Specific) ....................................................................................................................... 16 Application Notes (General) .................................................................................................................................... 16 PCB Design And Land Pattern Layout ............................................................................................................................. 17 PCB Material And Thickness .................................................................................................................................... 18 Handling Instructions ...................................................................................................................................................... 18 Pick And Place Equipment ....................................................................................................................................... 18 Reflow Solder ........................................................................................................................................................... 18 Board Wash.............................................................................................................................................................. 18 Outline Dimensions ......................................................................................................................................................... 19 Ordering Guide ........................................................................................................................................................ 20 Revision History ....................................................................................................................................................... 20 Compliance Declaration Disclaimer: ............................................................................................................................... 21 Environmental Declaration Disclaimer: .......................................................................................................................... 21 Document Number: DS-INMP441-00 Revision: 1.0 Page 3 of 21 INMP441 SPECIFICATIONS TABLE 1. ELECTRICAL CHARACTERISTICS (T A = -40 to 85C, V DD = 1.8 to 3.3 V, CLK = 2.4 MHz, C LOAD = 30 pF, unless otherwise noted. All minimum and maximum specifications are guaranteed across temperature, voltage, and clock frequency specified in Table 1, Table 2, Table 3, unless otherwise noted. Typical specifications are not guaranteed.) PARAMETER PERFORMANCE Directionality Sensitivity Signal-to-Noise Ratio (SNR) Equivalent Input Noise (EIN) Dynamic Range Frequency Response Total Harmonic Distortion (THD) Power-Supply Rejection (PSR) Maximum Acoustic Input Noise Floor POWER SUPPLY Supply Voltage (V DD ) Supply Current (I S ) CONDITIONS 1 kHz, 94 dB SPL 20 Hz to 20 kHz, A-weighted 20 Hz to 20 kHz, A-weighted Derived from EIN and maximum acoustic input Low frequency -3 dB point High frequency -3 dB point 105 dB SPL 217 Hz, 100 mVp-p square wave superimposed on V DD = 1.8 V Peak 20 Hz to 20 kHz, A-weighted, RMS -29 TYP Omni -26 61 33 -23 UNITS dBFS dBA dBA SPL dB 60 15 Hz kHz % 3 -75 dBFS 120 dB SPL -87 dBFS 3.63 V 1.6 mA 0.8 mA 2 A 2.5 0.8 4.5 mA mA A 17.2/fS sec f S = 48 kHz 359 s f S = 16 kHz 1078 s 0.04 dB dB kHz 1.4 Standby Power Down V DD = 3.3 V MAX 87 1.62 Normal Mode V DD = 1.8 V MIN Normal Mode Standby Power Down 2.2 NOTES 1 2 DIGITAL FILTER Group Delay Pass-Band Ripple Stop-Band Attenuation Pass Band 60 20.3 0.423 x f S Note 1: The peak-to-peak amplitude relative to peak-to-peak amplitude of (224 - 1.) The stimulus is a 104 dB SPL sinusoid having RMS amplitude of 3.1623 Pa. Sensitivity is relative to 1 Pa. Note 2: See Figure 4 and Figure 5. Document Number: DS-INMP441-00 Revision: 1.0 Page 4 of 21 INMP441 TABLE 2. I2S DIGITAL INPUT/OUTPUT CHARACTERISTICS PARAMETER CONDITIONS MIN Input Voltage High (V IH ) L/R, WS, SCK Input Voltage Low (V IL ) L/R, WS, SCK TYP MAX UNITS NOTES 0.7 x V DD V DD V 1 0 0.25 x V DD V 1 DIGITAL INPUT SD DIGITAL INPUT Voltage Output Low (VOL) VDD = 1.8 V, I SINK = 0.25 mA 0.1 x V DD V 1 Voltage Output Low (VOL) VDD = 1.8 V, I SINK = 0.7 mA 0.3 x V DD V 1 Voltage Output High (VOH) Voltage Output High (VOH) VDD = 1.8 V, I SINK = 0.7 mA VDD = 1.8 V, I SINK = 0.25 mA V V 1 1 Voltage Output Low (VOL) VDD = 3.3 V, I SINK = 0.5 mA 0.1 x V DD V 1 Voltage Output Low (VOL) VDD = 3.3 V, ISINK = 1.7 mA 0.3 x V DD V 1 Voltage Output High (VOH) VDD = 3.3 V, I SINK = 1.7 mA 0.7 x V DD V 1 Voltage Output High (VOH) VDD = 3.3 V, I SINK = 0.5 mA 0.9 x V DD V 1 UNITS ns NOTES 0.7 x V DD 0.9 x V DD Note 1: Limits based on characterization results; not production tested. TABLE 3. SERIAL DATA PORT TIMING SPECIFICATIONS PARAMETER t SCH CONDITIONS SCK high MIN 50 TYP t SCL SCK low 50 ns t SCP SCK period 312 ns f SCK SCK frequency 0.5 t WSS WS setup 0 ns t WSH WS hold 20 ns f WS WS frequency 7.8 3.2 50 TIMING DIAGRAM tSCP tSCH SCK tWSS tSCL tWSH WS SD Figure 1. Serial Data Port Timing Document Number: DS-INMP441-00 Revision: 1.0. Page 5 of 21 MAX MHz kHz INMP441 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 4. ABSOLUTE MAXIMUM RATINGS PARAMETER Supply Voltage (V DD ) Digital Pin Input Voltage Sound Pressure Level Mechanical Shock Vibration Temperature Range Biased Storage RATING -0.3 V to +3.63 V -0.3 V to V DD + 0.3 V or 3.63 V, whichever is less 160 dB 10,000 g Per MIL-STD-883 Method 2007, Test Condition B -40C to +85C -55C to +150C 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. Document Number: DS-INMP441-00 Revision: 1.0 Page 6 of 21 INMP441 SOLDERING PROFILE CRITICAL ZONE TL TO TP tP TP TEMPERATURE RAMP-UP TL tL TSMAX TSMIN tS RAMP-DOWN PREHEAT t25C TO PEAK TEMPERATURE TIME Figure 2. Recommended Soldering Profile Limits TABLE 5. RECOMMENDED SOLDERING PROFILE* PROFILE FEATURE Average Ramp Rate (T L to T P ) Sn63/Pb37 1.25C/sec max Pb-Free 1.25C/sec max 100C 100C 150C 200C 60 sec to 75 sec 1.25C/sec 60 sec to 75 sec 1.25C/sec 45 sec to 75 sec 183C ~50 sec 217C 215C +3C/-3C 260C +0C/-5C Time Within +5C of Actual Peak Temperature (t P ) 20 sec to 30 sec 20 sec to 30 sec Ramp-Down Rate 3C/sec max 3C/sec max Time +25C (t 25C ) to Peak Temperature 5 min max 5 min max Minimum Temperature (T SMIN ) Minimum Temperature Preheat (T SMIN ) Time (T SMIN to T SMAX ), t S Ramp-Up Rate (T SMAX to T L ) Time Maintained Above Liquidous (t L ) Liquidous Temperature (T L ) Peak Temperature (T P ) *The reflow profile in Table 5 is recommended for board manufacturing with InvenSense MEMS microphones. All microphones are also compatible with the J-STD-020 profile. Document Number: DS-INMP441-00 Revision: 1.0 Page 7 of 21 INMP441 PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS 6 GND WS 3 7 VDD GND 5 L/R 4 SD 2 SCK 8 CHIPEN 1 9 GND BOTTOM VIEW (Not to Scale) Figure 3. Pin Configuration TABLE 6. PIN FUNCTION DESCRIPTIONS PIN 1 NAME FUNCTION SCK Serial-Data Clock for IS Interface 2 SD Serial-Data Output for IS Interface. This pin tri-states when not actively driving the appropriate output channel. The SD trace should have a 100 k pulldown resistor to discharge the line during the time that all microphones on the bus have tri-stated their outputs. 3 WS Serial Data-Word Select for IS Interface 4 L/R Left/Right Channel Select. When set low, the microphone outputs its signal in the left channel of the IS frame. When set high, the microphone outputs its signal in the right channel. 5 GND Ground. Connect to ground on the PCB. 6 GND Ground. Connect to ground on the PCB. 7 VDD Power, 1.8 V to 3.3 V. This pin should be decoupled to Pin 6 with a 0.1 F capacitor. 8 CHIPEN 9 GND Microphone Enable. When set low (ground), the microphone is disabled and put in powerdown mode. When set high (VDD), the microphone is enabled. Ground. Connect to ground on the PCB. Document Number: DS-INMP441-00 Revision: 1.0. Page 8 of 21 INMP441 TYPICAL PERFORMANCE CHARACTERISTICS 10 10 8 4 AMPLITUDE (dB) SENSITIVITY (dB) 6 2 0 -2 -4 0 -10 -6 -8 -10 50 100 1k -20 10 10k FREQUENCY (Hz) -10 -20 PSR (dB) -30 -40 -50 -60 -70 10k FREQUENCY (Hz) Figure 6. Power-Supply Rejection (PSR) vs. Frequency Document Number: DS-INMP441-00 Revision: 1.0. 10k Figure 5. Typical Frequency Response (Measured) 0 1k 1k FREQUENCY (Hz) Figure 4. Frequency Response Mask -80 100 100 Page 9 of 21 INMP441 THEORY OF OPERATION The INMP441 is a high-performance, low-power, digital-output, omni-directional MEMS microphone with a bottom port. The complete INMP441 solution consists of a MEMS sensor, signal conditioning, an analog-to-digital converter, anti-aliasing filters, power management, and an industry-standard 24-bit IS interface. The INMP441 complies with the TIA-920 Telecommunications Telephone Terminal Equipment Transmission Requirements for Wideband Digital Wireline Telephones standard. UNDERSTANDING SENSITIVITY The casual user of digital microphones may have difficulty understanding the sensitivity specification. Unlike an analog microphone (whose specification is easily confirmed with an oscilloscope), the digital microphone output has no obvious unit of measure. The INMP441 has a nominal sensitivity of -26 dBFS at 1 kHz with an applied sound pressure level of 94 dB. The units are in decibels 23 referred to full scale. The INMP441 default full-scale peak output word is 2 - 1 (integer representation), and -26 dBFS of that scale 23 (-26/20) = 420,426. A pure acoustic tone at 1 kHz having a 1Pa RMS amplitude results in an output digital signal whose is (2 - 1) x 10 peak amplitude is 420,426. Although the industry uses a standard specification of 94 dB SPL, the INMP441 test method applies a 104 dB SPL signal. The higher sound pressure level reduces noise and improves repeatability. The INMP441 has excellent gain linearity, and the sensitivity test result at 94 dB is derived with very high confidence from the test data. POWER MANAGEMENT The INMP441 has three different power states: normal operation, standby mode, and power-down mode. Normal Operation 18 The microphone becomes operational 2 clock cycles (85 ms with SCK at 3.072 MHz) after initial power-up. The CHIPEN pin then controls the power modes. The part is in normal operation mode when SCK is active and the CHIPEN pin is high. Standby Mode 14 The microphone enters standby mode when the serial-data clock SCK stops and CHIPEN is high. Normal operation resumes 2 clock cycles (5 ms with SCK at 3.072 MHz) after SCK restarts. The INMP441 should not be transitioned from standby to power-down mode, or vice versa. Standby mode is only intended to be entered from the normal operation state. Power-Down Mode The microphone enters power-down mode when CHIPEN is low, regardless of the SCK operation. Normal mode operation resumes 17 2 SCK clock cycles (43 ms with SCK at 3.072 MHz) after CHIPEN returns high while SCK is active. 17 It always takes 2 clock cycles to restart the INMP441 after V DD is applied. It is not recommended to supply active clocks (WS and SCK) to the INMP441 while there is no power supplied to VDD. Doing this continuously turns on ESD protection diodes, which may affect long-term reliability of the microphone. Startup 18 The microphones have zero output for the first 2 SCK clock cycles (85ms with SCK at 3.072 MHz) following power-up. Document Number: DS-INMP441-00 Revision: 1.0. Page 10 of 21 INMP441 IS DATA INTERFACE The slave serial-data port's format is IS, 24-bit, twos complement. There must be 64 SCK cycles in each WS stereo frame, or 32 SCK cycles per data-word. The L/R control pin determines whether the INMP441 outputs data in the left or right channel. For a stereo application, the SD pins of the left and right INMP441 microphones should be tied together as shown in Figure 7. The format of a stereo IS data stream is shown in Figure 8. Figures 9 and 10 show the formats of a mono microphone data stream for left and right microphones, respectively. Data Output Mode The output data pin (SD) is tri-stated when it is not actively driving IS output data. SD immediately tri-states after the LSB is output so that another microphone can drive the common data line. The SD trace should have a pull-down resistor to discharge the line during the time that all microphones on the bus have tri-stated their outputs. A 100 k resistor is sufficient for this, as shown in Figure 7. Data Word Length The output data word length is 24 bits per channel. The INMP441 must always have 64 clock cycles for every stereo data-word (f SCK = 64 x f WS ). Data-Word Format The default data format is IS (two's complement), MSB-first. In this format, the MSB of each word is delayed by one SCK cycle from the start of each half-frame. FROM VOLTAGE REGULATOR (1.8V TO 3.3V) SD WS SCK SYSTEM MASTER (DSP, MICROCONTROLLER, CODEC) 0.1F 0.1F VDD VDD VDD CHIPEN L/R LEFT INMP441 VDD SCK SCK WS WS SD CHIPEN RIGHT SD INMP441 100k GND GND GND GND GND GND Figure 7. System Block Diagram Document Number: DS-INMP441-00 Revision: 1.0. Page 11 of 21 L/R INMP441 WS 1 3 2 24 4 26 25 34 33 32 36 35 64 58 57 56 SCK (64 x fS) SD (24-BIT) MSB LSB MSB LSB HIGH-Z HIGH-Z LEFT CHANNEL HIGH-Z RIGHT CHANNEL Figure 8. Stereo-Output IS Format WS 1 2 3 4 24 25 26 32 33 34 35 36 56 57 58 64 36 56 57 58 64 SCK (64 x fS) SD (24-BIT) MSB LSB HIGH-Z HIGH-Z LEFT CHANNEL Figure 9. Mono-Output IS Format Left Channel (L/R = 0) WS 1 2 3 33 32 26 25 24 4 34 35 SCK (64 x fS) SD (24-BIT) MSB LSB HIGH-Z RIGHT CHANNEL HIGH-Z Figure 10. Mono-Output IS Format Right Channel (L/R = 1) DIGITAL MICROPHONE SENSITIVITY The sensitivity of a PDM output microphone is specified in units of dBFS (decibels relative to a full-scale digital output). A 0 dBFS sine wave is defined as a signal whose peak just touches the full-scale code of the digital word (see Figure 5). This measurement convention means that signals with a different crest factor may have an RMS level higher than 0dBFS. For example, a full-scale square wave has an RMS level of 3dBFS. 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 11. 1 kHz, 0 dBFS Sine Wave The definition of a 0 dBFS signal must be understood when measuring the sensitivity of the INMP441. An acoustic input signal of a 1 kHz sine wave at 94 dB SPL applied to the INMP441 results in an output signal with a -26 dBFS level. This means that 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 dBFS; however, this is not the case because of the definition of a 0 dBFS sine wave. Document Number: DS-INMP441-00 Revision: 1.0. Page 12 of 21 INMP441 There is no commonly accepted unit of measurement to express the instantaneous level of a digital signal output from the microphone, as opposed to the RMS level of the signal. Some measurement systems express the instantaneous level of an individual sample in units of D, where 1.0 D is digital full scale (see Figure 11). In this case, a -26 dBFS sine wave has peaks at 0.05 D. For more information about digital microphone sensitivity, see the AN-1112 Application Note, Microphone Specifications Explained. SYNCHRONIZING MICROPHONES Stereo INMP441 microphones are synchronized by the WS signal, so audio captured from two microphones sharing the same clock will be in sync. If the mics are enabled separately, this synchronization may take up to 0.35 ms after the enable signal is asserted while internal data paths are flushed. DIGITAL FILTER CHARACTERISTICS The INMP441 has an internal digital band-pass filter. A high-pass filter eliminates unwanted low-frequency signals. A low-pass filter allows the user to scale the pass band with the sampling frequency, as well as perform required noise reduction. HIGH-PASS FILTER The INMP441 incorporates a high-pass filter to remove unwanted DC and very low frequency components. This shows the high-pass characteristics for a nominal sampling rate of 48 kHz. The cutoff frequency scales with changes in sampling rate. TABLE 7. HIGH PASS FILTER CHARACTERISTICS FREQUENCY ATTENTUATION 3.7 Hz -3 dB 10.4 Hz -0.5 dB 21.6 Hz -0.1 dB This digital filter response is in addition to the natural high-pass response of the INMP441 MEMS acoustic transducer that has a -3 dB cutoff of 60 Hz. LOW-PASS FILTER The analog-to-digital converter in the INMP441 is a single-bit, high-order, sigma-delta (-) running at a high oversampling ratio. The noise shaping of the converter pushes the majority of the noise well above the audio band and gives the microphone a wide dynamic range. However, it does require a good quality low-pass filter to eliminate the high-frequency noise. Figure 12 shows the response of this digital low-pass filter included in the microphone. The pass band of the filter extends to 0.423 x f S and, in that band, has an unnoticeable 0.04 dB of ripple. The high-frequency cutoff of -6 dB occurs at 0.5 x f S . A 48 kHz sampling rate results in a pass band of 20.3 kHz and a half amplitude corner at 24 kHz. The stop-band attenuation of the filter is greater than 60 dB. Note that these filter specifications scale with sampling frequency. Document Number: DS-INMP441-00 Revision: 1.0 Page 13 of 21 INMP441 0 -10 MAGNITUDE (dB) -20 -30 -40 -50 -60 -70 -80 -90 -100 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 NORMALIZED FREQUENCY (fS) Figure 12. Digital Low-Pass Filter Magnitude Response Document Number: DS-INMP441-00 Revision: 1.0 Page 14 of 21 1.0 INMP441 APPLICATIONS INFORMATION POWER-SUPPLY DECOUPLING For best performance and to avoid potential parasitic artifacts, placing a 0.1 F ceramic type X7R or better capacitor between Pin 7 (VDD) and ground is strongly recommended. The capacitor should be placed as close to Pin 7 as possible. The connections to each side of the capacitor should be as short as possible, and the trace should stay on a single layer with no vias. For maximum effectiveness, locate the capacitor equidistant from the power and ground pins, or if equidistant placement is not possible, slightly closer to the power pin. Thermal connections to the ground planes should be made on the far side of the capacitor, as shown in Figure 13. VDD GND CAPACITOR TO VDD TO GND Figure 13. Recommended Power-Supply Bypass Capacitor Layout Document Number: DS-INMP441-00 Revision: 1.0 Page 15 of 21 INMP441 SUPPORTING DOCUMENTS For additional information, see the following documents. EVALUATION BOARD USER GUIDE 2 UG-303, EV_INMP441Z-FX: Bottom Port I S Output MEMS Microphone Evaluation Board 2 UG-362, EV_INMP441Z SDP Daughter Board for the INMP441 I S MEMS Microphone APPLICATION NOTES (PRODUCT SPECIFIC) AN-0208, High Performance Digital MEMS Microphone's Simple Interface to SigmaDSP Audio Processor AN-0266, High Performance Digital MEMS Microphone Standard Digital Audio Interface to Blackfin DSP APPLICATION NOTES (GENERAL) AN-1003, Recommendations for Mounting and Connecting the Invensense, Inc., Bottom-Ported MEMS Microphones AN-1068, Reflow Soldering of the MEMS Microphone AN-1112, Microphone Specifications Explained AN-1124, Recommendations for Sealing Invensense, Inc., Bottom-Port MEMS Microphones from Dust and Liquid Ingress AN-1140, Microphone Array Beamforming Document Number: DS-INMP441-00 Revision: 1.0. Page 16 of 21 INMP441 PCB DESIGN AND LAND PATTERN LAYOUT Lay out the PCB land pattern for the INMP441 at a 1:1 ratio to the solder pads on the microphone package (see Figure 14.) Take care to avoid applying solder paste to the sound hole in the PCB. Figure 15 shows a suggested solder paste stencil pattern layout. The response of the INMP441 is not affected by the PCB hole size, as long as the hole is not smaller than the sound port of the microphone (0.25 mm, or 0.010 inch, in diameter). A 0.5 mm to 1 mm (0.020 inch to 0.040 inch) diameter for the hole is recommended. Align the hole in the microphone package with the hole in the PCB. The exact degree of the alignment does not affect the performance of the microphone as long as the holes are not partially or completely blocked. 1.05 (6x) 0.25 DIA. (THRU HOLE) 2.66 (4x) 0.96 1.33 (2x) 1.56 3.16 0.40 x 0.60 (8x) DIMENSIONS SHOWN IN MILLIMETERS Figure 14. Suggested PCB Land Pattern Layout 1.05 (6x) 0.20 1.05 2.66 (4x) 3.76 1.33 (2x) 1.6 1.07 0.350 x 0.550 (8x) 4.72 DIMENSIONS SHOWN IN MILLIMETERS Figure 15. Suggested Solder Paste Stencil Pattern Layout Document Number: DS-INMP441-00 Revision: 1.0. Page 17 of 21 INMP441 PCB MATERIAL AND THICKNESS The performance of the INMP441 is not affected by PCB thickness. The INMP441 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. 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 5. 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-INMP441-00 Revision: 1.0 Page 18 of 21 INMP441 OUTLINE DIMENSIONS 4.82 4.72 4.62 REFERENCE CORNER 0.40 x 0.60 (PINS 1-8) 4.10 REF PIN 1 0.30 1.07 1.05 BSC 1.56 DIA. 0.96 DIA. 1 3.86 3.76 3.66 4 2.66 BSC 5 3.14 REF 1.33 BSC 9 TOP VIEW 6 BOTTOM VIEW 1.05 0.98 0.88 0.73 REF SIDE VIEW 0.24 REF Figure 16. 9-Terminal Chip Array Small Outline No Lead Cavity [LGA_CAV] 4.72 mm x 3.76 mm x 1.00 mm Body Dimensions shown in millimeters PART NUMBER PIN 1 INDICATION 441 YY XXXX DATE CODE LOT TRACEABILITY CODE Figure 17. Package Marking Specification (Top View) Document Number: DS-INMP441-00 Revision: 1.0 0.275 0.250 DIA. 0.225 Page 19 of 21 INMP441 ORDERING GUIDE PART INMP441ACEZ-R0* TEMP RANGE -40C to +85C PACKAGE 9-Terminal LGA_CAV QUANTITY 4,500 INMP441ACEZ-R7 -40C to +85C 9-Terminal LGA_CAV 1,000 EV_INMP441-FX EV_INMP441 -- -- Flexible Evaluation Board Evaluation Board -- -- * - 13" Tape and Reel - 7" Tape and reel to be discontinued. Contact sales@invensense.com for availability. REVISION HISTORY REVISION DATE REVISION DESCRIPTION 02/06/2014 1.0 Initial Release Document Number: DS-INMP441-00 Revision: 1.0 Page 20 of 21 INMP441 Compliance Declaration Disclaimer: InvenSense believes this compliance information to be correct but cannot guarantee accuracy or completeness. Conformity documents for the above component constitutes 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 Environmental Declaration Disclaimer: InvenSense believes this environmental information to be correct but cannot guarantee accuracy or completeness. Conformity documents for the above component constitutes 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. (c)2014 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. (c)2014 InvenSense, Inc. All rights reserved. Document Number: DS-INMP441-00 Revision: 1.0. Page 21 of 21