原标题：Wolfson WM7220数字麦克风MEMS解决方案

　　Wolfson 公司的WM7220是小型数字硅麦克风,具有高信噪比(58dB)和低功耗(睡眠模式10uA,正常工作为650uA),它采用有所有权的CMOS/MEMS技术,集成了高性能ADC,PDM数字音频输出,工作电压1.6V-3.7V,广泛用在消费类电子产品包括手机,便携式设备,数码相机,数码摄影机,蓝牙手机,手提导航设备和多媒体播放器等.本文介绍了WM7220主要特性,方框图以及评估板电路图和材料费清单(BOM).

　　The WM7220 is a low-profile silicon digital microphone. It offers high Signal to Noise Ratio (SNR) and low power consumption and is suited to a wide variety of consumer

　　applications.

　　The WM7220 incorporates Wolfson’s proprietary CMOS/MEMS membrane technology, offering high reliability and high performance in a miniature, low-profile package. The WM7220 is designed to withstand the high temperatures associated with automated flow solder assembly processes. (Note that conventional microphones can be damaged by this process.)

　　The WM7220 incorporates a high performance ADC, which outputs a single-bit Pulse Density Modulated (PDM) audio data stream. The WM7220 supports selectable left/right channel assignment for a two-channel digital microphone interface, enabling efficient connection of multiple microphones in stereo/array configurations.

　　WM7220主要特性:

　　High SNR (58dB)

　　Low power

　　- Sleep mode - 10μA

　　- Normal operation - 650μA

　　Low profile packaging

　　Support for automated flow solder assembly

　　PDM digital audio output

　　Stereo/array operation

　　Proprietary ADC technology

　　- Reduced clock jitter sensitivity

　　- Low noise floor modulation

　　- Stable in overload condition

　　Top port package

　　1.64V to 3.7V supply

　　4.72 x 3.76 x 1.25mm thin package design

　　WM7220应用:

　　Mobile telephone handsets

　　Portable computers

　　Portable media players

　　Digital still cameras

　　Digital video cameras

　　Bluetooth headsets

　　Portable navigation devices

　　图1.WM7220方框图

　　图2.WM7220立体声数字麦克风和WM8903连接框图

　　WM7220评估板材料清单: