Описание
The LMV1089 is a fully analog dual differential input, differential output, microphone array amplifier designed to reducebackground acoustic noise, while delivering superb speech clarity in voice communication applications. The LMV1089 preserves near-field voice signals within 4cm of the microphones while rejecting far-field acoustic noise greaterthan 50cm from the microphones. Up to 20dB of far-field rejection is possible in a properly configured and calibrated system. Part of the Powerwise family of energy efficient solutions, the LMV1089 consumes only 1.1mA of supply current providing superiorperformance over DSP solutions consuming greater than ten times the power. A quick calibration during the manufacturing test process of the product containing the LMV1089 compensates the entire microphonesystem. This calibration compensates for mismatch in microphone gain and frequency response, as well as acoustical path variances.The LMV1089 stores the calibration coefficients in the on-chip EEPROM. The calibration is initiated by an I2C command or by a logic pin control. The dual microphone inputs and the processed signal output are differential to provide excellent noise immunity. The microphonesare biased with an internal low-noise bias supply.
