Nov. 16, 2006 — Infineon Technologies AG unveiled a silicon microphone for consumer and computer communications devices that is approximately one-half the size and operates on one-third the power of conventional microphones.
The company says its MEMS-based microphone achieves the same acoustic and electrical properties as conventional microphones, but is more rugged and exhibits higher heat resistance.
Infineon says its microphone can withstand temperatures of up to 260 degrees Celsius and is more immune to vibrations and shocks than conventional microphones. Due to the high temperature-resistance, it can be soldered without difficulty onto any standard PCB and is ideally suited to use on fully automated production lines common to mass market consumer products. A 1.5 to 3.3V power supply slashes the miniature microphone’s power consumption to about one third (70 µA) that of ECM microphones.
The microphone consists of two chips, the MEMS chip and an ASIC, both of which share the same package on a surface-mounted device. The MEMS consists of a rigid, perforated back electrode and a flexible silicon membrane that serves as a capacitor, transforming acoustic pressure waves into capacitive variations. The ASIC detects these variations, converts them into electrical signals and passes them to the appropriate processing devices, such as a baseband processor or amplifier. The technology used to manufacture the MEMS microphones was developed at Infineon in Villach, Austria.
The new silicon MEMS microphone broadens the Infineon existing portfolio of mechanical and radio-frequency MEMS products, which include accelerometers, gyroscopes and pressure sensors and bulk acoustic wave filters.