Packaged MEMS microphones offer enhanced far-field voice capture
This SNR is combined with a low distortion level of 10% at a 135 dB sound pressure level (SPL). In a 4 x 3 x 1.2 mm MEMS package, the microphones are suited for high-quality acoustic recordings and far field voice capturing applications.
“This is an expansion of the established high volume bare die MEMS and ASIC business model with our packaging partners around the world,” said Dr. Roland Helm, Senior Director and Head of Product Line Sensors for Infineon’s Power Management and Multimarket Division. “We will continue to strengthen and grow our business with our partners with bare dies [dice]; additionally we now address low noise high-end use cases with our two new packaged microphones.”
Current MEMS microphone technology uses a sound wave actuated membrane and a static backplate. Infineon’s dual backplate MEMS technology uses a membrane embedded within two backplates thus generating a truly differential signal. This allows improved high frequency immunity for better audio signal processing and increases the acoustic overload point of 10% Total Harmonic Distortion (THD) to 135 dB SPL.
The SNR of 70 dB is an improvement of 6 dB compared to a conventional MEMS microphone. This improvement is equivalent to doubling the distance from which a user can give a voice command that is captured by the microphone. Additionally, the analogue and digital microphones have close microphone-to-microphone matching (±1 dB sensitivity matching and ± 2° phase matching) which is suitable for implementing in arrays. For this reason the MEMS microphones are a good fit for ultra-precise beam forming and noise cancelling.
Engineering samples of the low noise packaged analog and digital MEMS microphones will be available in Q4/2017. Start of production will be in Q1/2018.