Packaged MEMS microphones with a 70dB signal-to-noise ratio

  

The analogue and digital microphones are based on the company’s dual backplate MEMS technology whereby a membrane is embedded within two backplates, which is said to generate a truly differential signal. Current MEMS microphone technology uses a sound wave actuated membrane and a static backplate.

According to the company, this allows improved high frequency immunity for better audio signal processing and increases the acoustic overload point of 10% total harmonic distortion to 135dB sound pressure level.

In a 4 x 3 x 1.2mm MEMS package, the company claims the microphones are well 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; additionally we now address low noise high end use cases with our two new packaged microphones.”

The signal-to-noise ratio of 70dB is said to be an improvement of 6dB compared to a conventional MEMS microphone. According to the company, 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 features ±1 dB sensitivity matching and ± 2° phase matching, useful for implementing in arrays. For this reason, the MEMS microphones are suited for ultra-precise beam forming and noise cancelling.