Infineon Technologies AG enters the packaged silicon microphone market with analog and digital microphones based on its dual backplate MEMS technology and specifying a 70-dB signal-to-noise ratio (SNR). This is combined with a distortion level of 10% at a 135-dB sound pressure level (SPL). In a 4 mm x 3 mm x 1.2 mm MEMS package, the microphones arel suited for high-quality acoustic recordings and far field voice capturing applications.
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 percent 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 analog and digital microphones have notable microphone-to-microphone matching (±1 dB sensitivity matching and ± 2° phase matching) which is ideal for implementing in arrays. For this reason the MEMS microphones are a perfect 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. More information is available at the Infineon Technologies website.