MEMS Microphone Simplifies Audio Design

A new MEMS microphone could make it easier for makers ofsmart phones, video cameras and voice recognition systems to employ multiple microphonesin a constrained space.

Known as the ADMP441MEMS (microelectromechanical systems) microphone, the new product is said to bethe first of its kind to incorporate an I2S (Inter-IC Sound),a standard serial bus interface for audio devices. By doing so, it is said toreduce complexity and cost, while freeing up space on printed circuit boards.

"Today, designers of microphone applications have to designan amplifier circuit, a codec circuit and a converter circuit," notes KieranHarney, product line director for AnalogDevices' MEMS/Sensors Technology Group, maker of the new microphone."Whereas with an I²S device, the only thing between the microphoneand the microprocessor is a wire. It totally simplifies the design of thoseapplications."

Harney says the technology is particularly well suited forapplications that need multiple microphones, but don't have a speakerassociated with each of the microphones. "In a lot of cases, people are tryingto put two, four, six or even eight microphones in their system," he says. "Andthey're finding themselves having to buy codecs or converters or amplifiersthat they really don't need. If they can get rid of all that, it saves them alot of cost and space."

Candidate applications for the new technology include videocameras and voice recognition systems, which don't necessarily need a speakerattached to every microphone. The microphone is said to be well suited forthose applications because it measures a scant 4.72 x 3.76 x 1.00 mm.

"Many new applications are trying to incorporate more thanone microphone," Harney says. "For customers in those high-performance,space-constrained applications, this MEMS microphone is an ideal solution."