WM7331E Bottom Port Analog Silicon Microphone DESCRIPTION FEATURES The WM7331 is a low-profile silicon analog microphone. It offers high Signal to Noise Ratio (SNR) and low power consumption and is suited to a wide variety of consumer applications. High SNR (63dB) Low variation in sensitivity (±1dB tolerance) Low current consumption (55µA) The WM7331 incorporates Cirrus Logic® proprietary CMOS/MEMS membrane technology, offering high reliability and high performance in a miniature, low-profile package. The compact integration of transducer and internal circuitry on a single die enables implementation within an extremely small package size. Analog output Bottom Port LGA Package 2.5mm x 1.6mm x 0.9mm package 1.6V to 3.6V supply The WM7331 is designed to withstand the high temperatures associated with automated flow solder assembly processes. (Note that conventional microphones can be damaged by this process.) APPLICATIONS Mobile phone handsets Wearable devices Portable media players The WM7331 offers tight tolerance on the microphone sensitivity, giving reduced variation between parts. This removes the need for in-line production calibration of part-topart microphone variations. Digital cameras BLOCK DIAGRAM 3D VIEW VDD WM7331 CHARGE PUMP AMP OUTPUT 2.50mm x 1.60mm x 0.90mm LGA package CMOS MEMS Transducer GND Pre-Production http://www.cirrus.com This document contains information for a product under development. Cirrus Logic reserves the right to modify this product. Copyright Cirrus Logic, Inc., 2014–2016 (All Rights Reserved) Rev 3.2 APR ‘16 WM7331E TABLE OF CONTENTS DESCRIPTION ................................................................................................................ 1 FEATURES ..................................................................................................................... 1 APPLICATIONS ............................................................................................................. 1 BLOCK DIAGRAM ......................................................................................................... 1 3D VIEW ......................................................................................................................... 1 TABLE OF CONTENTS.................................................................................................. 2 PIN CONFIGURATION ................................................................................................... 3 PIN DESCRIPTION ......................................................................................................... 3 ORDERING INFORMATION ........................................................................................... 3 ABSOLUTE MAXIMUM RATINGS ................................................................................. 4 IMPORTANT ASSEMBLY GUIDELINES ....................................................................... 4 RECOMMENDED OPERATING CONDITIONS .............................................................. 4 ACOUSTIC AND ELECTRICAL CHARACTERISTICS .................................................. 5 TERMINOLOGY ......................................................................................................................... 5 TYPICAL PERFORMANCE ............................................................................................ 6 APPLICATIONS INFORMATION ................................................................................... 7 RECOMMENDED EXTERNAL COMPONENTS ........................................................................ 7 CONNECTION TO A CIRRUS LOGIC CODEC ......................................................................... 8 PCB LAND PATTERN AND PASTE STENCIL .......................................................................... 9 PACKAGE DIMENSIONS ............................................................................................. 10 IMPORTANT NOTICE .................................................................................................. 11 REVISION HISTORY .................................................................................................... 12 2 Rev 3.2 WM7331E PIN CONFIGURATION 3 4 1 2 Top View PIN DESCRIPTION PIN NAME TYPE 1 VDD Supply 2 OUTPUT Analog Output 3 GND Supply 4 GND DESCRIPTION Analog supply Microphone analog output signal Analog ground Can be left floating (recommended), or connected to GND ORDERING INFORMATION ORDER CODE TEMPERATURE RANGE PACKAGE MOISTURE SENSITIVITY LEVEL PEAK SOLDERING TEMPERATURE WM7331IMSE/RV -40 to +100°C LGA (tape and reel) MSL2A +260°C Note: Reel quantity = 6000 All devices are Pb-free and Halogen free. Rev 3.2 3 WM7331E ABSOLUTE MAXIMUM RATINGS Absolute Maximum Ratings are stress ratings only. Permanent damage to the device may be caused by continuously operating at or beyond these limits. Device functional operating limits and guaranteed performance specifications are given under Electrical Characteristics at the test conditions specified. ESD Sensitive Device. This device is manufactured on a CMOS process. It is therefore generically susceptible to damage from excessive static voltages. Proper ESD precautions must be taken during handling and storage of this device. Cirrus Logic tests its package types according to IPC/JEDEC J-STD-020 for Moisture Sensitivity to determine acceptable storage conditions prior to surface mount assembly. These levels are: MSL1 = unlimited floor life at <30°C / 85% Relative Humidity. Not normally stored in moisture barrier bag. MSL2 = out of bag storage for 1 year at <30°C / 60% Relative Humidity. Supplied in moisture barrier bag. MSL2A = out of bag storage for 4 weeks at <30°C / 60% Relative Humidity. Supplied in moisture barrier bag. MSL3 = out of bag storage for 168 hours at <30°C / 60% Relative Humidity. Supplied in moisture barrier bag. The Moisture Sensitivity Level for each package type is specified in Ordering Information. CONDITION MIN MAX Supply Voltage (VDD) -0.3V +4.2V Operating temperature range, TA -40°C +100°C Storage temperature prior to soldering 30°C max / 60% RH max Storage temperature after soldering -40°C +100°C IMPORTANT ASSEMBLY GUIDELINES Do not put a vacuum over the port hole of the microphone. Placing a vacuum over the port hole can damage the device. Do not board wash the microphone after a re-flow process. Board washing and the associated cleaning agents can damage the device. Do not expose to ultrasonic cleaning methods. Do not use a vapour phase re-flow process. The vapour can damage the device. Please refer to application note WAN0273 (MEMS MIC Assembly and Handling Guidelines) for further assembly and handling guidelines. RECOMMENDED OPERATING CONDITIONS PARAMETER 4 SYMBOL MIN TYP MAX UNIT Analog Supply Range VDD 1.6 1.8 3.6 V Ground GND 0 V Rev 3.2 WM7331E ACOUSTIC AND ELECTRICAL CHARACTERISTICS Test Conditions: VDD=1.8V, 1kHz test signal, TA = 25°C, unless otherwise stated. PARAMETER SYMBOL TEST CONDITIONS MIN Directivity Polarity Sensitivity Positive sound pressure S Acoustic Overload Total Harmonic Distortion Signal to Noise Ratio Dynamic Range TYP MAX UNIT Omni-directional THD 94dB SPL Positive output voltage -39 -38 dBV 124 dB SPL 94dB SPL 0.04 % 114dB SPL 0.3 120dB SPL 1 SNR A-weighted 63 DR A-weighted 89 Frequency Response -37 No Load, THD < 10% -3dB low frequency 70 +3dB high frequency dB dB 100 Hz 15000 Frequency Response Flatness 200Hz to 8kHz -1 +1 dB Part-to-Part Phase Matching 80Hz to 100Hz ±10 ° 200Hz ±5 Acoustic Noise Floor A-weighted 31 dB SPL Electrical Noise Floor A-weighted -101 dBV PSRR 217Hz sine wave, 100mV (peak-peak) 62 dB PSR 217Hz square wave, 100mV (peak-peak) -88 dBV Power Supply Rejection Ratio Power Supply Rejection Current Consumption IVDD 55 60 µA Output DC Impedance ZOUT 200 400 Ω TERMINOLOGY 1. 2. 3. 4. 5. Sensitivity (dBV) - Sensitivity is a measure of the microphone output response to the acoustic pressure of a 1kHz 94dB SPL (1Pa RMS) sine wave. Total Harmonic Distortion (%) – THD is the ratio of the RMS sum of the harmonic distortion products in the specified bandwidth (see note below) relative to the amplitude of the fundamental (ie. test frequency) output. Signal-to-Noise Ratio (dB) – SNR is a measure of the difference in level between the output response of a 1kHz 94dB SPL sine wave and the idle noise output. Dynamic Range (dB) – DR is the ratio of the 1% THD microphone output level (in response to a sine wave input) and the idle noise output level. All performance measurements are carried out within a 20Hz to 20kHz bandwidth and, where noted, an A-weighted filter. Failure to use these filters will result in higher THD and lower SNR values than are found in the Acoustic and Electrical Characteristics. The low pass filter removes out of band noise. Rev 3.2 5 WM7331E TYPICAL PERFORMANCE Sensitivity vs. Frequency (20Hz–20kHz) Sensitivity vs. Frequency (20kHz–80kHz) PSRR vs. Frequency Sensitivity vs. Supply Voltage Current Consumption vs. Supply Voltage THD vs. Sound Pressure Level Phase Response vs. Frequency (20Hz–10kHz) 6 Rev 3.2 WM7331E APPLICATIONS INFORMATION RECOMMENDED EXTERNAL COMPONENTS WM7331 VDD C + OUTPUT 1F R GND Figure 1 WM7331 Recommended External Components A DC-blocking output capacitor is required on the OUTPUT pin, as illustrated in Figure 1. A single capacitor is required for a single-ended connection. The capacitor must be correctly selected as it affects the cut-off frequency of the output path. A low cut-off frequency is desirable as it means there is no significant filtering of the audio bandwidth. The 3dB cut-off frequency of the output path is given by the equation below, where C is the output capacitance and R is the input resistance of the other circuit. 3dB filter roll-off frequency = 1 2 p RC A typical recommended configuration, with 1uF DC-blocking capacitor and 20kΩ minimum input circuit impedance, gives a 3dB cut-off frequency of 10Hz or less. Tantalum electrolytic capacitors are particularly suitable for the DC-blocking components as they offer high stability in a small package size. Rev 3.2 7 WM7331E CONNECTION TO A CIRRUS LOGIC CODEC Cirrus Logic provides a range of audio CODECs incorporating an analog microphone input interface; these support connection to silicon microphones such as the WM7331. The recommended connection of a WM7331 silicon microphone is illustrated in Figure 2 (for singleended mode) and Figure 3 (for pseudo-differential mode). A DC blocking capacitor is required, as described in the previous section. A 2.2µF decoupling capacitor is also recommended; this should be positioned close to the VDD pin of the WM7331. Further information on Cirrus Logic audio CODECs is provided in the respective product datasheet, which is available from the Cirrus Logic website. 2.2F WM7331 VDD Audio CODEC MICBIAS OUTPUT 1F Analogue Input pin (eg. IN1xP) GND Figure 2 WM7331 Silicon Microphone Single-ended Connection 2.2F WM7331 VDD Audio CODEC MICBIAS OUTPUT GND 1F Non-Inverting Input pin (eg. IN1xP) 1F Inverting Input pin (eg. IN1xN) Figure 3 WM7331 Silicon Microphone Pseudo-differential Connection 8 Rev 3.2 WM7331E PCB LAND PATTERN AND PASTE STENCIL The recommended PCB Land Pattern and Paste Stencil Pattern for the WM7331 microphone are shown in Figure 4 and Figure 5. See also Application Note WAN0284 (General Design Considerations for MEMS Microphones) for further details of PCB footprint design. Full definition of the package dimensions is provided in the “Package Dimensions” section. Figure 4 DM131 – PCB Land Pattern, Top View Figure 5 DM131 – Paste Stencil, Top View Rev 3.2 9 WM7331E PACKAGE DIMENSIONS 10 Rev 3.2 WM7331E IMPORTANT NOTICE Contacting Cirrus Logic Support For all product questions and inquiries, contact a Cirrus Logic Sales Representative. To find one nearest you, go to www.cirrus.com. "Pre-Production" product information describes products that are in production, but for which full characterization data is not yet available. For the purposes of our Terms and Conditions of Sale, "Preliminary" or "Advanced" datasheets are non-final datasheets that include but are not limited to datasheets marked as “Target”, “Advance”, “Product Preview”, “Preliminary Technical Data” and/or “Pre-production.” Products provided with any such datasheet are therefore subject to relevant terms and conditions associated with "Preliminary" or "Advanced" designations. The products and services of Cirrus Logic International (UK) Limited; Cirrus Logic, Inc.; and other companies in the Cirrus Logic group (collectively either “Cirrus Logic” or “Cirrus”) are sold subject to Cirrus Logic’s terms and conditions of sale supplied at the time of order acknowledgment, including those pertaining to warranty, indemnification, and limitation of liability. Software is provided pursuant to applicable license terms. Cirrus Logic reserves the right to make changes to its products and specifications or to discontinue any product or service without notice. Customers should therefore obtain the latest version of relevant information from Cirrus Logic to verify that the information is current and complete. Testing and other quality control techniques are utilized to the extent Cirrus Logic deems necessary. Specific testing of all parameters of each device is not necessarily performed. In order to minimize risks associated with customer applications, the customer must use adequate design and operating safeguards to minimize inherent or procedural hazards. Cirrus Logic is not liable for applications assistance or customer product design. The customer is solely responsible for its selection and use of Cirrus Logic products. Use of Cirrus Logic products may entail a choice between many different modes of operation, some or all of which may require action by the user, and some or all of which may be optional. Nothing in these materials should be interpreted as instructions or suggestions to choose one mode over another. Likewise, description of a single mode should not be interpreted as a suggestion that other modes should not be used or that they would not be suitable for operation. Features and operations described herein are for illustrative purposes only. CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF DEATH, PERSONAL INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE (“CRITICAL APPLICATIONS”). CIRRUS LOGIC PRODUCTS ARE NOT DESIGNED, AUTHORIZED OR WARRANTED FOR USE IN PRODUCTS SURGICALLY IMPLANTED INTO THE BODY, AUTOMOTIVE SAFETY OR SECURITY DEVICES, NUCLEAR SYSTEMS, LIFE SUPPORT PRODUCTS OR OTHER CRITICAL APPLICATIONS. INCLUSION OF CIRRUS LOGIC PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TO BE FULLY AT THE CUSTOMER’S RISK AND CIRRUS LOGIC DISCLAIMS AND MAKES NO WARRANTY, EXPRESS, STATUTORY OR IMPLIED, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR PARTICULAR PURPOSE, WITH REGARD TO ANY CIRRUS LOGIC PRODUCT THAT IS USED IN SUCH A MANNER. IF THE CUSTOMER OR CUSTOMER’S CUSTOMER USES OR PERMITS THE USE OF CIRRUS LOGIC PRODUCTS IN CRITICAL APPLICATIONS, CUSTOMER AGREES, BY SUCH USE, TO FULLY INDEMNIFY CIRRUS LOGIC, ITS OFFICERS, DIRECTORS, EMPLOYEES, DISTRIBUTORS AND OTHER AGENTS FROM ANY AND ALL LIABILITY, INCLUDING ATTORNEYS’ FEES AND COSTS, THAT MAY RESULT FROM OR ARISE IN CONNECTION WITH THESE USES. This document is the property of Cirrus Logic and by furnishing this information, Cirrus Logic grants no license, express or implied, under any patents, mask work rights, copyrights, trademarks, trade secrets or other intellectual property rights. Any provision or publication of any third party’s products or services does not constitute Cirrus Logic’s approval, license, warranty or endorsement thereof. Cirrus Logic gives consent for copies to be made of the information contained herein only for use within your organization with respect to Cirrus Logic integrated circuits or other products of Cirrus Logic, and only if the reproduction is without alteration and is accompanied by all associated copyright, proprietary and other notices and conditions (including this notice). This consent does not extend to other copying such as copying for general distribution, advertising or promotional purposes, or for creating any work for resale. This document and its information is provided “AS IS” without warranty of any kind (express or implied). All statutory warranties and conditions are excluded to the fullest extent possible. No responsibility is assumed by Cirrus Logic for the use of information herein, including use of this information as the basis for manufacture or sale of any items, or for infringement of patents or other rights of third parties. Cirrus Logic, Cirrus, the Cirrus Logic logo design, and SoundClear are among the trademarks of Cirrus Logic. Other brand and product names may be trademarks or service marks of their respective owners. Copyright © 2014–2016 Cirrus Logic, Inc. All rights reserved. Rev 3.2 11 WM7331E REVISION HISTORY DATE REV 01/04/14 1.0 Initial version 29/09/14 2.0 3D image added Electrical Characteristics updated Package Outline Drawing added 1 5 8 PH 08/10/14 2.0 Test Pin (pin 4) added to Pin Configuration & Pin Description 4 PH 24/03/15 2.1 Frequency response updated PCB Land Pattern and Paste Stencil added Package Drawing updated 5 8 9 PH 27/05/15 2.2 Released for general distribution 06/11/15 3.0 Frequency response updated Typical performance graphs added 5 6 PH 01/03/16 3.1 Frequency response performance graphs updated 6 PH 26/04/16 3.2 Phase variation specification and performance plot added 5, 6 PH 12 DESCRIPTION OF CHANGES PAGE CHANGED BY CT PH Rev 3.2