By Bruce Rose, Principal Applications Engineer, CUI Inc
Many of today’s smart devices such as home digital assistants and IoT sensors are required to “hear” their environment. There is a growing demand for microphones that are not only highly miniaturized, but also robust, easy to design-in, and resistant to nearby acoustic or electrical noise.
Fortunately, designers have options, as both MEMS (Micro-Electro-Mechanical System) and electret condenser microphone (ECM) technologies are viable solutions. Both operate along similar principles, leveraging the deflection of a diaphragm acting as a capacitor plate to cause a change in electrical properties. This is then amplified (and subsequently converted and encoded in the case of digital MEMS microphones) to produce an audio signal for the host system. On the other hand, aspects such as the internal circuitry, packaging and application-circuit design associated with each type differ significantly so that each has unique strengths relative to the other.
While MEMS microphones may win where ultimate miniaturization, superior digital noise immunity or close matching between devices is required, ECMs offer compelling advantages in certain situations. For instance, higher Ingress Protection (IP) ratings can be achieved, a wider variety of termination types is available, they can tolerate a more loosely regulated supply voltage, and they can be the best choice when upgrading a legacy design.
In the CUI Insights blog, “Comparing MEMS and Electret Condenser (ECM) Microphones”, find out more about the two most common microphone technologies, and how to make the best selection for your application.
