STMicroelectronics : MP34DT01-M – MEMS microphone supports voice recognition in novel user interfaces

The MP34DT01-M from STMicroelectronics is a tiny, low-power MEMS microphone with a digital audio-signal output.

Its capacitive-sensing element, capable of detecting acoustic waves, is manufactured using a silicon micro-machining process developed specifically for the production of audio sensors. Its IC interface is made in a CMOS process which enables the creation of a dedicated signal-processing circuit. Its digital signal output is provided in pulse-density modulation format.

Average current in normal operation is 0.6mA. The MP34DT01-M also has a power-down mode in which the current it draws is just 20μA. The MP34DT01-M has an acoustic overload point of 120dB Sound Pressure Level (SPL). The signal-to-noise ratio is 61dB, and the microphone’s omnidirectional sensitivity is -26dBFS. The MP34DT01-M is available in a top-port, surface-mount, EMIshielded package measuring 3mm x 4mm x 1mm. It is guaranteed to operate over an extended temperature range from – 40°C to 85°C.


  • Supply-voltage range: 1.64V to 3.6V
  • 10ms maximum turn-on time
  • <1% total harmonic distortion and noise at 100dBSPL


  • Portable media players
  • VoIP terminals
  • Speech-recognition equipment
  • eLearning devices
  • Gaming and virtual-reality input devices
  • Theft-prevention systems

MEMS Microphone applications
The STEVAL-MKI155V3 board is a daughterboard to be used with the STEVAL-MKI126Vx Smart Voice kit. It contains four MP34DT01-M digital MEMS microphones. When connected to the Smart Voice board, it is possible to detach the single PCBs hosting each microphone.

Orderable Part Number: STEVAL-MKI155V3