MEMS Microphone-Amp Chip Breaks Acoustics Ground

June 9, 2003

Designed for hearing aids and cell-phone microphones, this advanced-design IC portends "killer" applications.

A combination MEMS microphone/amplifier chip holds the promise of generating large-scale applications for hearing aids and cell phones. According to Akustica's CEO and CTO, Kaigham (Ken) Gabriel, the company believes its new chip will make a major impact in applications where space constraints and performance demands are critical, due to its relatively low cost.

The analog chip is a multimembrane CMOS IC that holds an array of 64 micromachined condenser microphones etched in silicon. Also incorporated on the 3- by 3.65- by 0.5-mm chip is a MOSFET amplifier.

The chip's omnidirectional performance characteristics include a sensitivity (at 1 V/Pa) of -40 to +4 dB and a target noise level of 35 dB SPL (sound pressure level). Frequency range is 100 Hz to 10,000 kHz. The device typically operates from a 3-V supply (5 V maximum) and consumes less than a mere 130 µA. This level of performance requires much larger chips of electret microphones than those being used in hearing aids today.

The chip accepts a maximum input sound level of 110 dB and produces an analog output voltage. Future versions might also integrate analog-to-digital converters (ADCs) for digital outputs, providing even higher levels of noise immunity.

While the chip's exact price has yet to be set, Akustica believes it will fall between $1 and $7 for OEM quantities. Sample quantities will be available this summer.

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Akustica Inc.www.akustica.com (412) 390-1730

About the Author

Roger Allan

Roger Allan is an electronics journalism veteran, and served as Electronic Design's Executive Editor for 15 of those years. He has covered just about every technology beat from semiconductors, components, packaging and power devices, to communications, test and measurement, automotive electronics, robotics, medical electronics, military electronics, robotics, and industrial electronics. His specialties include MEMS and nanoelectronics technologies. He is a contributor to the McGraw Hill Annual Encyclopedia of Science and Technology. He is also a Life Senior Member of the IEEE and holds a BSEE from New York University's School of Engineering and Science. Roger has worked for major electronics magazines besides Electronic Design, including the IEEE Spectrum, Electronics, EDN, Electronic Products, and the British New Scientist. He also has working experience in the electronics industry as a design engineer in filters, power supplies and control systems.

After his retirement from Electronic Design Magazine, He has been extensively contributing articles for Penton’s Electronic Design, Power Electronics Technology, Energy Efficiency and Technology (EE&T) and Microwaves RF Magazine, covering all of the aforementioned electronics segments as well as energy efficiency, harvesting and related technologies. He has also contributed articles to other electronics technology magazines worldwide.

He is a “jack of all trades and a master in leading-edge technologies” like MEMS, nanolectronics, autonomous vehicles, artificial intelligence, military electronics, biometrics, implantable medical devices, and energy harvesting and related technologies.