Despite the proliferation of electronics devices that integrate voice, music, and video, the quality of sound produced by these handheld electronics has not lived up to consumer expectations. Analog Devices, well-known to audiophiles for its high-fidelity audio technology, has created a microphone capable of high-fidelity audio/video playback, conference calling, TIA-920-compliant. VoIP (voice-over-IP), voice recognition, and other functions. ADI combined audio applications know-how with MEMS (micro-electromechanical systems) technology to design a new family of microphones with the industry’s highest SNR (signal-to-noise ratio) of greater than 61-dB A-weighted. Today, the highest quality sound available in a cell phone, for example, is just 55 dB. The new omni-directional input microphones are available with digital output or analog output and deliver the industry’s flattest frequency response from 100Hz to greater than 15 kHz – and with a package size and cost tailored to the design considerations of portable electronics manufacturers.

Compared with electret condenser microphones MEMS microphones have several advantages: they can be manufactured using surface mounting, withstand high reflow temperatures, are easily integrated with CMOS processes and other audio electronics, and they offer improved noise cancellation and immunity to RF and EMI.

The ADMP421 PDM (pulse density modulated) digital output MEMS microphone is designed for multimedia and VoIP-enabled cell phones, Bluetooth headsets and other systems that rely on high quality digitized voice and audio. The digital output of the new ADMP421 microphone provides high immunity to coupled noise from RF (radio frequency) and EMI (electromagnetic interference) emanating from sources such as WiFi antennas and LCD (liquid crystal displays) clock signals. By eliminating the need for analog signal conditioning, as well as the cable shielding materials commonly required to route analog signals, system designers can optimize the placement of the ADMP421 digital MEMS microphone to improve audio-enhancement features, such as stereo sound and array beam forming. The ADMP421 features 80 dB FS PSRR (power supply rejection ratio), Left/Right select, and integrated sleep mode.

In addition to providing the industry’s best SNR and frequency response, Analog Devices’ ADMP401 analog output MEMS microphone delivers superior PSRR of better than 50 dBV, simplifying power supply design requirements to the microphone for near-field and far-field applications.

The ADMP401 analog output MEMS microphone is available in a thin 4.72 x 3.76 x 1.0mm surface mount package.

For further information please contact your local Sasco Holz branch office.