LOW-COST METHOD FOR TESTING THE SIGNAL-TO-NOISE RATIO OF MEMS MICROPHONES

摘要

A method is provided for testing a MEMS microphone. The MEMS microphone includes a pressure sensor positioned within a housing and a pressure input port to direct acoustic pressure from outside the housing towards the pressure sensor. An acoustic pressure source provides acoustic pressure to the MEMS microphone. A reference microphone is positioned proximal to the MEMS microphone. An output signal of the MEMS microphone and an output signal of the reference microphone are compared. A common signal component is removed from the output signal of the MEMS microphone and the output signal of the MEMS microphone is analyzed for noise due to the construction of the device and for a signal-to-noise ratio of the device. Based on the noise signal and the signal-to-noise ratio, the MEMS microphone is rejected or accepted.