如何制作低功耗数字MEMS麦克风

关键词： ADI , ADMP441 , MEMS , 麦克风

　　MEMS“ title=”MEMS“》MEMS” title=“MEMS”》MEMS麦克风，包括有MEMS传感器，信号调理，ADC，抗混淆滤波器，电源管理以及工业标准的24位I2S接口，并直接连到数字处理器如DSP和MCU.SNR为61 BA，灵敏度为−26 dBFS，平坦的频率响应60Hz到15kHz，主要用在远程会议，游戏控制台，移动设备，笔记本电脑，平板电脑和安全系统。本文介绍了ADMP4411主要特性，方框图，系统框图和评估板子板EVAL-ADMP441Z电路图，材料清单。

　　The ADMP4411 is a high performance， low power， digital output， omnidirectional MEMS microphone with a bottom port. The complete ADMP441 solution consists of a MEMS sensor， signal conditioning， an analog-to-digital converter， antialiasing filters， power management， and an industry standard 24-bit I2S interface. The I2S interface allows the ADMP441 to connect directly to digital processors， such as DSPs and microcontrollers， with-out the need for an audio codec in the system.

　　The ADMP441 has a high SNR and high sensitivity， making it an excellent choice for far field applications. The ADMP441 has a flat wideband frequency response， resulting in natural sound with high intelligibility. A built-in particle filter provides high reliability.

　　The ADMP441 is available in a thin 4.72 mm × 3.76 mm × 1 mm surface-mount package. It is reflow solder compatible with no sensitivity degradation. The ADMP441 is halide free.

　　ADMP4411主要特性：

　　Digital I²S 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 mm × 3.76 mm × 1 mm surface-mount package

　　Compatible with Sn/Pb and Pb-free solder processes

　　RoHS/WEEE compliant

　　ADMP4411应用：

　　Teleconferencing systems

　　Gaming consoles

　　Mobile devices

　　Laptops

　　Tablets

　　Security systems

　　

　　图1.ADMP4411功能框图

　　

　　图2.ADMP4411系统框图

　　评估板子板EVAL-ADMP441Z

　　EVAL-ADMP441Z SDP Daughter Board for the ADMP441 I2S MEMS Microphone

　　The EVAL-ADMP441Z is an evaluation board that works with the EVAL-ADMP441Z-FLEX and the system demonstration platform （SDP） to allow quick evaluation of the performance of the ADMP441 MEMS microphone. This evaluation system can be used to stream two channels of audio from two ADMP441 microphones to a PC over a USB connection. The system identifies itself to a PC as a standard USB audio interface; therefore， no additional drivers or software are required to run the system. One EVAL-ADMP441Z-FLEX board is included in the evaluation kit. The SDP-B controller board is purchased separately. The EVAL-ADMP441Z board also provides hardware control and probe/test points to examine the digital signals of the ADMP441.

　　评估套件包括：

　　EVAL-ADMP441Z daughter board

　　EVAL-ADMP441Z-FLEX board

　　5 V power supply

　　

　　图3.评估板子板EVAL-ADMP441Z外形图

　　

　　图4.评估板子板EVAL-ADMP441Z电路图

　　评估板子板EVAL-ADMP441Z材料清单：