LMV1089 Datasheet, PDF (1/37 Pages) National Semiconductor (TI) – Dual Input, Far Field Noise Suppression Microphone Amplifier with Automatic Calibration Capability

LMV1089
www.ti.com
SNAS441H – SEPTEMBER 2008 – REVISED MAY 2010
LMV1089 Dual Input, Far Field Noise Suppression Microphone Amplifier with Automatic
Calibration Capability
Check for Samples: LMV1089
FEATURES
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•2 Low Power Consumption
• Shutdown Function
• No Added Processing Delay
• Differential Inputs and Outputs
• Automatic Calibration
• Adjustable 6 - 48dB Gain
• Excellent RF Immunity
• Space-Saving 36–Bump DSBGA Package
APPLICATIONS
• Headset and Boom Microphones
• Mobile Handsets and Two-Way Radios
• Bluetooth and Other Powered Headsets
• Hand-Held Voice Microphones
• Equalized Stereo Microphone Preamplifier
KEY SPECIFICATIONS
• Far Field Noise Suppression
(Electrical), (f = 1kHz) 37 dB
• Supply Voltage 2.7 to 5.5 V
• Supply Current 1.1 mA (typ)
• Standby Current 0.7 µA (typ)
• Signal-to-Noise Ratio (A-weighted) 65 dB (typ)
• Total Harmonic Distortion + Noise 0.1 % (typ)
• PSRR (217Hz) 96 dB (typ)
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
communication 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 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 superior performance 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 microphone system. 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 microphones are biased with an
internal low-noise bias supply.
Far-field noise, > 50 cm
Traffic _Noise
Loud _Music
Crowd Noise
Announcements
Machine ^Noise
Up to 4 cm
LMV1089
Pure analog solution
provides superior
performance over DSP
solutions
Low-cost
omnidirectional
microphones
Analog
Filter
Near-Field Voice
EEPROM
Far field noise reduced
by up to 20 dB in properly
configured and calibrated
system
Figure 1.
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2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
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