Memsensing MEMS Microphones

Analog MEMS microphones output a continuous voltage signal proportional to sound pressure, offering simplicity and lower power consumption. Digital MEMS microphones output PDM (Pulse Density Modulation) data, providing better noise immunity and direct digital interface. Analog microphones are ideal for basic audio applications with simple ADCs. Digital microphones eliminate analog signal path noise and are preferred for multi-microphone arrays and applications requiring long traces. Memsensing offers both types with equivalent acoustic performance.

Choose analog for simple, cost-sensitive designs. Select digital for multi-mic arrays, noisy environments, or when direct processor interface is preferred.

Microphone sensitivity determines the output level for a given sound pressure. Typical values range from -42dBV to -26dBV for analog microphones. Higher sensitivity (-26dBV) provides stronger output for quiet sources but may clip with loud sounds. Lower sensitivity (-42dBV) handles louder sources without distortion. For normal speech applications (smartphones, voice assistants), -38dBV to -42dBV is typical. For quiet environment recording, choose higher sensitivity. Consider your system's ADC input range and expected sound levels when selecting sensitivity.

Match microphone sensitivity to your expected sound levels and system ADC capabilities. Contact our FAE for application-specific recommendations.

SNR (Signal-to-Noise Ratio) measures the ratio of desired audio signal to microphone self-noise, expressed in dB. Higher SNR means cleaner audio capture, especially important for quiet sounds. Consumer applications typically require 58-64dB SNR. Professional audio may need 65dB+. SNR affects the microphone's ability to capture distant or quiet sources clearly. Memsensing microphones offer competitive SNR specifications ranging from 58dB to 65dB depending on the model. For voice recognition applications, SNR above 60dB is recommended for reliable performance.

Select SNR based on your application's noise requirements - 60dB+ for voice recognition, 58dB+ for general consumer applications.

Standard MEMS microphones have limited environmental protection and are designed for indoor consumer electronics. For outdoor or harsh environment applications, consider: 1) Adding external acoustic mesh or membrane protection

2) Using sealed enclosures with acoustic ports

3) Selecting automotive-qualified microphones with enhanced reliability

4) Implementing conformal coating on the PCB. Memsensing automotive microphones (AEC-Q100 qualified) offer improved reliability for demanding applications. For extreme environments, additional external protection is recommended.

For outdoor use, implement proper environmental protection or select automotive-qualified microphones. Contact our FAE for harsh environment recommendations.

Digital MEMS microphones using PDM output can share a common data line with different clock polarities (left/right channel selection). Typical configurations include: 1) Dual microphones sharing CLK and DATA lines with opposite LR pin connections

2) Multiple microphones using time-division multiplexing on shared bus

3) Individual data lines with shared clock for arrays. The processor's PDM interface or decimation filter must support the chosen configuration. Memsensing digital microphones support standard PDM timing compatible with most processors and audio codecs.

Plan your microphone array configuration based on processor capabilities. Our FAE team can provide reference designs for multi-microphone arrays.