By switching clock frequency to trade bandwidth and SNR, the microphone can also be operated in a 420μA power saving mode and a 180μA in low power mode. There is also a 25μA (50μA max) stand-by with the output disabled.
It “masters the difficult task of switching between different power and performance profiles without any audible artifacts”, claimed the company.
Frequency response can be almost flat up to 10kHz and rolls off at 30Hz.
Sensitivity is typically -37dBFS (1kHz 94dBSPL) in all operating modes, and acoustic overload typically occurs at 128dBSPL (10% THD, 2nd to 5th harmonics, 1kHz).
The internal asic delivers a PDM (pulse density modulated) output, and a pad is available to allow two of the microphones to share a single PDM bus in stereo applications with no drop in performance, with one transmitting on the rising edge of the PDM clock and the other on the falling edge.
Operation is across 1.62 – 3.60 V and -40 to 85°C, and the 3.50 x 2.65 x 1mm package hears from underneath through a hole in the PCB and is sealed to IP57. “The acoustic port in the PCB should be larger than the acoustic port of the microphone to
ensure optimal performance. A diameter of 0.6mm is recommended”, said Infineon.
The IM69D128S product page can be found here
