ST's new MP34DB01 MEMS microphone
6 May 2012
acoustic sensor technology has been developed which is much more immune to
mechanical vibration, temperature variations, and electromagnetic interference
while providing high-fidelity reproduction of audio signals with very low power
ST Microelectronics has teamed up with Omron Corporation to produce
the new MP34DB01 digital MEMS microphone, which integrates ST's electronic control circuit and Omron Corporation's micro-machined sensor in a
The MP34DB01 is an omni-directional sound-sensing device with a
built-in capacitive sensing element and an IC interface with stereo operation
capability. Omni-directional sensitivity improves sound quality by detecting
and filtering out background noise.
device is the first top-port digital MEMS microphone with better acoustic
parameters than bottom-port microphones.
A new patentable top port technology
enables the microphone membrane to be placed closer to the acoustic port hole
on the top of the package and still provide a substantial increase in
performance with the same size package.
It is the first microphone ever to be
is equipped with a top-port sound-inlet with a signal-to-noise (SNR) ratio of
63 dB and a flat frequency response in the audio band of 20-20,000 Hz.
acoustic sensing element is made using a special silicon micromachining process
designed to produce audio sensors. The IC interface is manufactured using a
CMOS process that allows designing a dedicated circuit able to provide a
digital signal externally in PDM format.
MP34DB01 has an acoustic overload point of 120 dBSPL with a very high 62.6 dB
signal-to-noise ratio and -26 dBFS sensitivity. It is contained in a
SMD-compliant, EMI-shielded package and has an extended temperature range from
-30 °C to +85 °C.
These features make the microphones perfect for applications
like speech-recognition systems, where speech is used to control software
applications or other types or voice activated actuators.
This microphone would
also work well in noisy industrial applications, where the high signal-to-noise
ratio and dynamic range make them ideal for devices like phonometers.
low power requirements and tiny 3x4x1 mm package, the device has a huge
potential in consumer applications like cell phones, tablets, media player,
video cameras, or other applications where small size, high sound quality,
reliability, and affordability are critical factors.
microphones can be used in the same device and set up in an array to increase
the filtering levels and provide even better sound quality. The Smart Voice
audio processors within the device make use of the enhanced capabilities of ST’s
digital MEMS microphones in multi-microphone arrays, enabling features like
acoustic echo cancellation, noise suppression, or beam-forming, which is a
sound-processing technique that helps isolate a sound and its location.