Fairchild's digital microphone series converts ECM outputs to digital PDM data streams

SAN JOSE, USA: Fairchild Semiconductor expanded its high-performance analog mobile audio device portfolio with the introduction of the FAN3850x series of digital microphone pre-amplifiers, including the FAN3850A 16dB or 19dB gain and the FAN3850T with 15dB gain and added temperature compensation.

These devices integrate a pre-amplifier, Low Drop-Out Regulator (LDO) and Analog-to-Digital Converter (ADC) that converts Electret Condenser Microphone (ECM) outputs to digital pulse density modulation (PDM) data streams. This provides advanced noise rejection capabilities as well as an easy interface to mobile handset processors – resulting in better sound quality.

Features and benefits
* FAN3850A features both 16dB and 19dB gain versions.
* FAN3850T offers 15dB gain and includes integrated negative temperature coefficient to compensate for ECM positive temperature coefficient to achieve a flat sensitivity response over temperature.
* Pre-amplifier accepts analog signals from the ECM and drives an over-sampled sigma delta ADC and outputs Pulse Density Modulation (PDM) data streams.
* Powered from the system supply rails, 1.64V to 3.63V, with lower power consumption of only 0.8mW and less than 20µW in power down mode.
* Excellent signal to noise ratio (SNR), lower distortion, and high power supply rejection even at high sound pressure levels (SPL).
* Suitable for use in mobile handset and notebook microphone applications.