LMV1091

LMV1091 Dual Input, Far Field Noise Suppression Microphone Amplifier October 28, 2009 LMV1091 Dual Input, Far Field Noise Suppression Microphone Amplifier General Description The LMV1091 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 communication applications. The LMV1091 preserves near-field voice signals within 4cm of the microphones while rejecting far-field acoustic noise greater than 50cm from the microphones. Up to 20dB of farfield rejection is possible in a properly configured and using ±0.5dB matched micropohones. Part of the Powerwise™ family of energy efficient solutions, the LMV1091 consumes only 600μA of supply current providing superior performance over DSP solutions consuming greater than ten times the power. 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 * SNRIE Supply voltage Supply current Standby current Signal-to-Noise Ratio (Voice band) Total Harmonic Distortion + Noise PSRR (217Hz) 34dB (typ) 26dB (typ) 2.7V to 5.5V 600μA (typ) 0.1μA (typ) 65dB (typ) 0.1% (typ) 99dB (typ)   *FFNSE at f = 1kHz Features ■ ■ ■ ■ ■ ■ ■ ■ No loss of voice intelligibility Low power consumption Shutdown function No added processing de...