New MEMS microphone from ADI simplifies voice recognition

Analog Devices has introduced new MEMS microphones for quality audio capture even in a noisy background. These TIA-920-compliant microphones with built-in processing capabilities are suggested for high-fidelity audio/video playback, voice recognition applications, and for phones with hands free feature.

The two new MEMS microphones ADMP404 and ADMP405 does a bit of audio signal processing internally and deliver SNR (signal-to-noise ratio) of 62 dB A-weighted and the highest PSRR (power supply rejection ratio) of 70 dBV with integrated high-pass filtering. ADI says this is an industry's best specification for a MEMS microphone.

The portable electronic devices such as phones audio/video capturing devices can now use this microphone to generate intelligible voice quality without the background noise/hiss directly from the microphone leads. The external noise is common with most of the normal microphones without built-in signal processing capabilities.

ADMP404 with a sensitivity of -38 dBV deliver flat frequency response from 100 Hz to 15 kHz while ADMP404 in the frequency range of 200 Hz to 15 kHz. These signal processing capable microphones saves the additional hardware otherwise required to clean up the ambient noise such as fan-noise, wind noise or any continuous and repetitive noise signal in the range. As the computers and phones getting keyboard less, the natural interface such as voice need this kind of smart sensors.

"There's a growing recognition by system designers that poor microphone performance at the front end significantly increases requirements for downstream audio processing. This leads to higher power consumption, higher cost and a more complex system design," said Mark Martin, vice president, MEMS/Sensor Group, Analog Devices

The omnidirectional ADMP404 packs MEMS microphone element, an impedance converter, and an output amplifier. The built-in particle filter enhances reliability. With all the above features, the ADMP405 additionally features low-frequency 200 Hz roll-off to reduce wind noise. ADMP404 and ADMP405 are suitable for capturing audio both at close distance as well as from sources from long distance.

The ADMP404 and ADMP405 are available in a small and thin 3.35 mm × 2.50 mm × 0.88 mm surface-mount package that is reflow-solder-compatible with no sensitivity degradation. The ADMP404 and ADMP405 are halide-free.

Availability: Now in samples and volumes by Jun 2010
Price: Each $1.79 per unit in 1,000-unit quantities
To know more visit http://www.analog.com/Microphones