Digital MEMS microphones from Wolfson target high-quality audio processing in mobile devices

(October 27, 2010) — Fabless audio chip company Wolfson Microelectronics plc (LSE: WLF.L) launched its next-generation digital silicon micro-electro-mechanical-systems (MEMS) microphones, the WM7210 and the WM7220. The digital MEMS are manufactured with Wolfson’s CMOS/MEMS membrane design, similar to the company’s analog MEMS microphones.

The WM7210 and the WM7220 complement Wolfson’s family of analog MEMS microphones. Based on Wolfson’s proprietary CMOS/MEMS membrane technology, the new digital devices deliver high reliability and performance, and can withstand the high temperatures needed for automated flow solder assembly, which can damage conventional microphones.

Wolfson’s digital MEMS microphones combine low power consumption, excellent audio capture, signal-to-noise (SNR) ratio of 59dB -Top port, low total harmonic distortion (THD) at high sound pressure levels, and a miniature low-profile package, suiting applications including mobile phones, PCs, portable media players, digital still cameras, and navigation devices. Audio is again becoming a differentiator in low- and high-tier consumer electronics devices, said Ron Schaeffer, audio hub product manager at WFL.L.

The WM7210 and WM7220 also help save battery life with ultra low sleep mode power consumption.  When the clock delivered to the microphone drops below a specified frequency, the microphones automatically power down into a sleep mode consuming just 2.5 micro amps.

Each microphone incorporates a high-performance ADC, which outputs a single bit Pulse Density Modulated (PDM) format audio data stream, while the microphone output can be defined for left or right configuration allowing for applications requiring stereo operation. The package is designed to accommodate various porting requests.

The WM7210 is available in a 4 x 3 x 1mm thin package design, priced at $1.83 in 1K volume, while the WM7220 is available in a 4.72 x 3.76 x 1.25mm, priced at $1.83 in 1K volume.

Wolfson entered the MEMS market with the acquisition of Oligon in January 2007. iSuppli noted their venture into the MEMS space, stating that this “factor will accelerate the penetration of MEMS microphones in the 2009-2012 timeframe.” Schaeffer noted with the digital MEMS launch that, “Complexity of audio capture and playback, across various platforms, and often in challenging environments, is leading to the integration of multiple (up to 8) microphones into a single smartphone, for example.” MEMS offer a more robust microphone chip, and are seeing adoption across major OEMs, he added, saying that product designers want drop-in package solutions from large-scale suppliers.

Wolfson Microelectronics supplies high-performance, mixed-signal semiconductor solutions to the consumer electronics market.Wolfson Microelectronics plc is listed on the London stock exchange (LSE: WLF.L).  For more information about Wolfson Microelectronics, visit: 

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