LMV1051 LMV1051 PRODUCT BRIEF Processor for Dual Microphone Adaptive Noise Cancelling with Wind Noise Alert Literature Number: SNAS508 September 21, 2010 Processor for Dual Microphone Adaptive Noise Cancelling with Wind Noise Alert General Description Features The LMV1051-LLP is an ultra-low power signal processor that processes the signals from 2 ECM or MEMS microphones to create an adaptive beam forming noise reduction system. The LMV1051-LLP processor is intended to be integrated with microphones (ECMs or MEMS). By using a proprietary National algorithm, the processor extracts a clean intelligible signal from noisy environments through the use of an adaptive directional pattern. The resulting solution can reduce noise by up to 30 dB, resulting in a significant improvement to the signal-to-noise ratio (SNR). The signal processing does not introduce artifacts into the talker’s voice. The desired signal is unmodified, which improves intelligibility and speech recognition accuracy. The LMV1051-LLP is designed to replace a standard ECM using a two-wire or three-wire interface. The entire module, including the processing IC, is powered from the mic bias supply. The resulting system uses less power than an individual ECM giving the end-product designer the ability to upgrade current designs without modifying the existing circuit. The result is an easy-to-use, low cost microphone alternative, providing superior noise reduction for end users. Notice: This document is not a full datasheet. For more information regarding this product or to order samples please contact your local National Semiconductor sales office or visit http://www.national.com/support/dir.html ■ Superior Noise Cancellation ■ ■ ■ ■ ■ ■ ■ ■ ■ — Dual Mic Technology — Active Directional Pattern — Up to 30dB peak noise rejection of stationary and nonstationary noise sources — No distortion of desired signal — Flat Frequency Response Wind Noise Alert and Protection — Automatically reduces wind noise by ≈ 20 dB (vs. directional mic) — Wind Noise Alert can be used to further reduce impact of wind on desired signal Ultra-Low Power Consumption — 210 μA (typical) including mic bias — Battery-free operation in wired headsets Compatible with Standard ECM Interfaces — 2-wire or 3-wire interface — Powered from mic bias supply Complete Signal Processing Solution — No Software Required — Enables a fully integrated mic module Zero-Latency Signal Processing Noise Cancelling or Omni-Directional Output Better EMI Noise rejection than ECM Supports Telephony Bandwidth Small Size 3 x 3 mm Applications ■ Wired Headset ■ Webcams ■ Cellular or Cordless Handsets © 2010 National Semiconductor Corporation 301336 www.national.com LMV1051 PRODUCT BRIEF LMV1051 PRODUCT BRIEF LMV1051 Block Diagram 30133601 Typical Applications Circuit 30133602 www.national.com 2 LMV1051 Notes 3 www.national.com LMV1051 PRODUCT BRIEF Notes For more National Semiconductor product information and proven design tools, visit the following Web sites at: www.national.com Products Design Support Amplifiers www.national.com/amplifiers WEBENCH® Tools www.national.com/webench Audio www.national.com/audio App Notes www.national.com/appnotes Clock and Timing www.national.com/timing Reference Designs www.national.com/refdesigns Data Converters www.national.com/adc Samples www.national.com/samples Interface www.national.com/interface Eval Boards www.national.com/evalboards LVDS www.national.com/lvds Packaging www.national.com/packaging Power Management www.national.com/power Green Compliance www.national.com/quality/green Switching Regulators www.national.com/switchers Distributors www.national.com/contacts LDOs www.national.com/ldo Quality and Reliability www.national.com/quality LED Lighting www.national.com/led Feedback/Support www.national.com/feedback Voltage References www.national.com/vref Design Made Easy www.national.com/easy www.national.com/powerwise Applications & Markets www.national.com/solutions Mil/Aero www.national.com/milaero PowerWise® Solutions Serial Digital Interface (SDI) www.national.com/sdi Temperature Sensors www.national.com/tempsensors SolarMagic™ www.national.com/solarmagic PLL/VCO www.national.com/wireless www.national.com/training PowerWise® Design University THE CONTENTS OF THIS DOCUMENT ARE PROVIDED IN CONNECTION WITH NATIONAL SEMICONDUCTOR CORPORATION (“NATIONAL”) PRODUCTS. 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