An Introduction to analog and digital MEMS microphone interfaces


CUI’s Bruce Rose explains the different types of MEMS microphone interfaces and how to select the right one for the job.

The market share for MEMS (micro-electro-mechanical systems) microphones has been rising steadily, driven by the growing popularity of voice-controlled electronics such as digital home assistants and voice-enabled navigation devices. But to properly apply them in your next project, it is important to understand the differences in electrical interfaces available.

MEMS microphones designed with an analog output provide a straightforward interface with the host circuit. Driven by an internal amplifier, the microphone reaches a reasonable signal level with a relatively low output impedance. Loudspeakers or radio communication systems are common applications that benefit from an analog electrical interface. Furthermore, an analog output is likely to exhibit lower power consumption than MEMS microphones with a digital output due to the absence of an analog-to-digital converter (ADC).

An ADC is useful when a digital output signal is delivered from a MEMS microphone and applied to digital circuitry, like a digital signal processor or a microcontroller. MEMS microphones with a digital interface also typically encode their output signals with pulse density modulation (PDM), giving them improved electrical noise immunity and bit error tolerance compared to analog versions.

In this CUI Insights blog, CUI’s Principal Applications Engineer, Bruce Rose, considers the importance of fully understanding MEMS microphone interfaces so you can confidently select the right one for the job.

Read the full blog post here.