Tiniest MEMS mic goes digital

With a die measuring just 1 x 1 mm, the omnidirectional CMOS device provides a PDM output that integrates easily with digital electronics

Designed to provide improved voice quality in laptops and other portable consumer electronics, the AKU2002C MEMS omnidirectional digital microphone integrates on a single, 1-mm2 monolithic die all the MEMS and logic circuitry needed to produce a digital pulse-density-modulated output. Devices are fabricated using standard CMOS processes.

For design flexibility, the device’s PDM output is a single-bit digital stream that can be decimated by a digital filter in downstream electronics. For stereo functionality, the output of two microphones can be multiplexed on a single wire. The device’s digital output inherently provides high immunity to RF and EM interference, which can be a costly, intractable problem with analog-output microphones. Typical PSRR is −57 dB, SNR is 56 dBA at 1 kHz, and frequency range is 50 Hz to 22 kHz. The device consumes 7 µA quiescent and 750 µA in operation (no load) from a 3-V source.

The microphone is available off the shelf in a 3.76 x 4.72-mm industry-standard package that is pin- and footprint-compatible with earlier devices; delivery in die/wafer form is also possible. The surface-mountable device is RoHS compliant and can be handled by automated pick-and-place machines. ($2.09 ea / 1,000 — sample qty available now; prod qty 1st qtr 2009.)

Akustica , Pittsburgh , PA
Information 412-390-1730

http://www.akustica.com