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Top Port Analog Silicon Microphone http://www.cirrus.com Copyright Cirrus Logic, Inc., 2014–2016 (All Rights Reserved) Rev 4.1 MAR ‘16 WM7121PE
DESCRIPTION
The WM7121P 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. The WM7121P incorporates Cirrus Logic ® proprietary CMOS/MEMS membrane technology, offering high reliability and high performance in a miniature, low -profile package. The WM7121P is designed to withstand the high temperatures associated with a utomated flow solder assembly processes. (Note that conventional microphones can be damaged by this process.) The WM7121P Top Port microphone offers matched performance to the WM7132P Bottom Port microphone. The matched characteristics enable highly accura te sound pick - up in opposite directions, suitable for noise cancellation and other DSP algorithms. The WM7121P offers tight tolerance on the microphone sensitivity, giving reduced variation between parts. This removes the need for in -line production calibration of part - to-part microphone variations.
FEATURES
High SNR (65dB) Low variation in sensitivity (±1dB tolerance) Matched pair with Bottom Port microphone WM7132P - Matched sensitivity, roll-off, and phase response Low current consumption (190µA) Analog output Top Port LGA Package 1.5V to 3.7V supply
APPLICATIONS
Mobile phone handsets Portable media players Digital still cameras Digital video cameras Bluetooth™ headsets Portable navigation devices Portable games consoles BLOCK DIAGRAM CMOS MEMS Transducer VDD CHARGE PUMP GND WM7121P AMP OUTPUT 3D VIEW 3.76mm x 2.95mm x 1.10mm LGA package
2 Rev 4.1 TABLE OF CONTENTS
Rev 4.1 3 PIN CONFIGURATION Top View PIN DESCRIPTION PIN NAME TYPE DESCRIPTION
1 VDD Supply Analog Supply
2 GND Supply Analog ground
3 GND Supply Analog ground
4 OUTPUT Analogue Output Microphone analog output signal
ORDERING INFORMATION
WM7121PIMSE/RV -40 to +100°C LGA (tape and reel) MSL2A +260°C Note: Reel quantity = 5000 All devices are Pb-free and Halogen free.
4 Rev 4.1 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 SYMBOL MIN TYP MAX UNIT Analog Supply Range VDD 1.5 3.7 V Ground GND 0 V
Rev 4.1 5 ACOUSTIC AND ELECTRICAL CHARACTERISTICS Test Conditions: VDD=2.1V, 1kHz test signal, TA = 25°C, unless otherwise stated. PARAMETER SYMBOL TEST CONDITIONS MIN TYP MAX UNIT Directivity Omni-directional Polarity Positive sound pressure Positive output voltage Sensitivity S 94dB SPL -39 -38 -37 dBV Acoustic Overload No Load, THD < 10% 126 dB SPL Total Harmonic Distortion THD 100dB SPL 0.1 1 % 114dB SPL 0.2 122dB SPL 1 Signal to Noise Ratio SNR A-weighted 65 dB Dynamic Range DR A-weighted 93 dB Frequency Response -3dB low frequency 62 Hz +3dB high frequency 13000 Frequency Response Flatness 200Hz to 6kHz -1 +1 dB Acoustic Noise Floor A-weighted 29 dB SPL Electrical Noise Floor A-weighted -103 dBV Power Supply Rejection Ratio PSRR 217Hz sine wave, 100mV (peak-peak) 46 dB Power Supply Rejection PSR 217Hz square wave, 100mV (peak-peak) -72 dBV Current Consumption IVDD 190 240 µA Output DC Impedance ZOUT 55 150 Ω TERMINOLOGY 1. Sensitivity (dBV) – Sensitivity is a measure of the microphone output response to the acoustic pressure of a 1kHz 94dB SPL (1Pa RMS) sine wave. 2. 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. 3. 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. 4. 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. 5. All performance measur ements 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.
6 Rev 4.1 TYPICAL PERFORMANCE Sensitivity vs. Frequency PSRR vs. Frequency Sensitivity vs. Supply Voltage Current Consumption vs. Supply Voltage THD vs. Sound Pressure Level
Rev 4.1 7 APPLICATIONS INFORMATION RECOMMENDED EXTERNAL COMPONENTS OUTPUT VDD GND 1F C R WM7121P Figure 1 WM7121P 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 desi rable 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 RCp
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 componen ts as they offer high stability in a small package size. OPTIMISED SYSTEM RF DESIGN For optimised RF design please refer to document WAN0278 (Recommended PCB Layout for Microphone RF Immunity in Mobile Cell Phone Applications) for further information.
10 Rev 4.1 PACKAGE DIMENSIONS
Rev 4.1 11 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. 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 specific ations or to discontinue any product or service without notice. Customers should therefore obtain the latest version of relevant informati on 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 a lteration 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 an y 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. Bluetooth is a trademark of Bluetooth SIG, Inc.
12 Rev 4.1
REVISION HISTORY
DATE REV DESCRIPTION OF CHANGES PAGE CHANGED BY 26/02/14 1.0 First Release IS 25/03/14 2.0 Formatting and miscellaneous updates throughout document Electrical Characteristics updated Package Outline Drawing updated 1-9 PH 13/06/14 3.0 Electrical Characteristics updated Typical Performance graphs added PCB Stencil drawings updated Package Outline Drawing updated PH 05/01/15 4.0 Updated to Rev 4.0 (Production) status PH 19/10/15 4.1 Frequency response updated Package Outline Drawing updated 5, 6 PH