There are three architectural approaches to microelectromechanical systems (MEMS) microphones, miniature devices used in a wide range of products. Capacitive microelectromechanical systems (MEMS) microphones are embedded in billions of consumer electronics. Solder-compatible; providing tight part-to-part sensitivity matching—all in a small footprint—capacitive MEMS microphones have demonstrated improved performance in recent years. State-of-the-art digital capacitive MEMS microphones can now achieve up to 72dB signal-to-noise ratio (SNR), with a 22dBA noise floor ; overall dynamic range in the order of 106 dB.
However, capacitive MEMS microphone technology has now reached the limits of its architecture, which constrains the key audio performance metrics: SNR; acoustic overload point (AOP).
Piezoelectric MEMS microphones have not demonstrated SNR performance exceeding 65dB,; require new materials to be developed to increase their performance. Optical MEMS microphones—a new architectural approach that combines a laser optical subsystem, a MEMS; advanced CMOS circuit design—has exceeded the limits of capacitive technology. With 80dB SNR supporting a 14 dBA noise floor, 132 dB dynamic range,; a 146dB AOP, optical MEMS microphones accomplish studio-quality performance in a tiny form factor that supports semiconductor-level yields in high-volume manufacturing.
This presentation will explain the architectural advancements of optical MEMS microphones in comparison to capacitive MEMS microphones. It will provide example use cases of high-SNR; high-AOP microphones in high volume applications.
