Wolfson 公司的WM7220是小型數(shù)字硅麥克風(fēng),具有高信噪比(58dB)和低功耗(睡眠模式10uA,正常工作為650uA),它采用有所有權(quán)的CMOS/MEMS技術(shù),集成了高性能ADC,PDM數(shù)字音頻輸出,工作電壓1.6V-3.7V,廣泛用在消費類電子產(chǎn)品包括手機(jī),便攜式設(shè)備,數(shù)碼相機(jī),數(shù)碼攝影機(jī),藍(lán)牙手機(jī),手提導(dǎo)航設(shè)備和多媒體播放器等.本文介紹了WM7220主要特性,方框圖以及評估板電路圖和材料費清單(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應(yīng)用:
Mobile telephone handsets
Portable computers
Portable media players
Digital still cameras
Digital video cameras
Bluetooth headsets
Portable navigation devices
圖1.WM7220方框圖
圖2.WM7220立體聲數(shù)字麥克風(fēng)和WM8903連接框圖
圖3.WM7220評估板功能方框圖
圖4.WM7220評估板電路圖(USB接口)
圖5.WM7220評估板電路圖(WM8804 SPDIF接口)
圖6.WM7220評估板電路圖(音頻選擇)
圖7.WM7220評估板電路圖(WM8903)
圖8.WM7220評估板電路圖(音頻I/O)
圖9.WM7220評估板電路圖(電源)
WM7220評估板材料清單:
圖10.WM7220評估板PCB頂層視圖
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