Single-chip MEMS-based Digital Microphone Shrinks to Fit Laptops, Notebooks

The insides of laptop and table computers are inherently noisy environments. Keyboards and antennas create interference for electronically sensitive devices, such as the system microphone. Fortunately for designers, MEMS (microelectromechanical-system)-based digital microphones are inherently noise-resistant. Akustica has released its fourth-generation AKU230 chip, which the company claims is the only MEMS-based digital microphone to include the microphone membrane, amplifier, and sigma-delta converter on one die, which measures just 7mm². Bosch in 2009 purchased Akustica; the part is the first in the Bosch supply chain.

The AKU230 package fits the industry-standard footprint of 3.76×4.72mm and measures 1.25mm tall in its LGA package. It features -26dB±2dB sensitivity, 56dB typical SNR (signal-to-noise ratio), and -57dB PSSR (power-supply-rejection ratio). Its closely matched sensitivity control and stereo-microphone data multiplexing are important for dual-microphone arrays that allow directionality and noise suppression.

Akustica