STMicroelectronics Enables Even More Interactive Portables with New Microphone Interface Chip

Consumer-electronic applications requiring a microphone are increasing, as users expect to use their PCs for voice calls, use voice commands to control devices such as GPS receivers and automotive systems, and record audio directly onto portable media devices. In addition, mobile devices such as cellphones that have traditionally featured one microphone are now adding extra microphones to support active noise cancellation for improved user experience.

Although demand for embedded microphones is increasing, little extra space – if any – is available inside the enclosure. Designers need solutions that make the microphone smaller and allow the essential interface circuitry to be mounted on the printed circuit board. ST’s EMIF02-MIC07F3 is a next-generation device integrating the complete noise filtering, ESD (electrostatic discharge) protection and biasing for one microphone in a single IC occupying only 1.37mm2. The single chip replaces multiple discrete components that consume at least 20.8mm2.

The EMIF02-MIC07F3 also enhances performance by using ST’s advanced PZT (Lead Zirconium Titanate) process, which allows high capacitance values within ultra-miniature dimensions. This gives designers extra freedom to optimize the filter characteristics. In addition, as all of the interface components are fabricated on a single chip, close matching between the capacitor and resistor values produces more repeatable performance than is possible with discrete components. This enhances the quality of the end product.

Major features of the EMIF02-MIC07F3:

* 1.17 x 1.17mm ST IPAD™ (Integrated Passive and Active Devices) package
* IEC 61000-4-2 Level 4 ESD protection
* High capacitance-density PZT technology: 45nF per mm²
* Single-chip solution enables:
o Simplified design
o Faster time to market
o Enhanced reliability
o Efficient supply-chain management