LMV1089 Datasheet | National Semiconductor

Description The LMV1089 is a fully analog dual differential input, differential output, microphone array amplifier designed to reduce background acoustic noise, while delivering superb speech .. clarity in voice munication applications. The LMV1089 preserves near-field voice signals within 4cm of the microphones while rejecting far-field acoustic noise greater than 50cm from the microphones. Up to 20d B of farfield rejection is possible in a properly configured and calibrated system. Part of the Powerwise™ family of energy efficient solutions, the LMV1089 consumes only 1.1m A of supply current providing superior performance over DSP solutions consuming greater than ten times the power. A quick calibration during the manufacturing test process of a product containing the LMV1089 pensates the entire microphone system. This calibration pensates 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 mand or by a logic pin control. The dual microphone inputs and the processed signal output are differential to provide excellent noise immunity. The microphones are biased with an internal low-noise bias supply. Key Specifications - - - - - - - Far Field Noise Suppression Electrical Supply voltage Supply current Standby current Signal-to-Noise Ratio (A-weighted) Total Harmonic Distortion + Noise PSRR (217Hz) 33d B 2.7V to 5.5V 1.1m A (typ) 0.7μA (typ) 65d B (typ) 0.1% (typ) 96d B (typ) Features - - - - - - - - Low power consumption Shutdown function No added processing delay Differential outputs Automatic calibration Adjustable 6 - 48d B gain Excellent RF immunity Space-saving 36- bump micro SMD package Applications - - - - - Headset and Boom microphones Mobile and handheld two-way radios Bluetooth and other powered headsets Hand-held voice microphones Equalized stereo microphone preamplifier FIGURE 1. © 2008 National...