Tutorial for MEMS microphones （教程为MEMS麦克风）.pdf

AN4426 Application note Tutorial for MEMS microphones Introduction This application note serves as a tutorial for MEMS microphones, providing general characteristics of these devices, both acoustic and mechanical, as well as summarizing the portfolio available from ST. MEMS microphones target all audio applications where small size, high sound quality, reliability and affordability are key requirements. STs MEMS microphones are designed, developed and manufactured within ST, creating an industry- unique, vertically integrated supply chain. Both analog and digital-input, top and bottom-port solutions are available. Our best-in-class AOP and SNR make ST鈥檚 MEMS microphones suitable for applications that require a very high dynamic range, improving the audio experience in any environment. Matching very tight sensitivity allows optimizing beamforming and noise cancelling algorithms for multi-microphone arrays. Low power consumption allows extending battery life. February 2017 DocID025704 Rev 2 1/20 Contents AN4426 Contents 1 Mechanical specifications, construction details4 2 Acoustic parameters 11 2.1 Sensitivity 11 2.2 Directionality 11 2.3 SNR 12 2.4 Dynamic range and acoustic overload point 12 2.5 Equivalent input noise 13 2.6 Frequency response 15 2.7 Total harmonic distortion 16