Product Brief
Analog audio subsystem integrates noise suppression for smartphones
Rich Pell7/28/2010 3:23 PM EDT
Comment
kdboyce
National Semiconductor pioneered the audio subsystem category for mobile phones ...
National Semiconductor has announced the LM49155 analog audio subsystem with integrated noise reduction for mobile phones and other portable handheld applications. Designed to maintain voice quality in noisy environments while using minimum power consumption, the device enables the rapid integration of noise suppression performance in phone handsets.
The device combines a noise suppression microphone amplifier, a 1.35-W mono class-D amplifier with ALC, a class-AB earpiece driver with AGC, a high-efficiency, stereo, ground-referenced headphone amplifier with click/pop suppression and I2C mode select and volume control. Quiescent current consumption is 3.7 mA for the earpiece amplifier and microphone amplifier signal path.
The LM49155's uplink noise suppression technology rejects far-field noise at 34 dB at 1 kHz through a two-microphone amplifier implementation. Downlink voice intelligibility is improved by enhancing the SNR (by 16 dB typ) between the handset's earpiece signal level and the ambient noise level.
The LM49155 is packaged in a 36-bump micro SMD package measuring 3.4 x 3.4 mm. Pricing is $2.25 each in 1,000-unit quantities.
Related Link:
LM49155 information page
LM49155 Product Brief (PDF)
|
|
|
|
|
Most Popular
Datasheets.com Parts Search
185 million searchable parts
(please enter a part number or hit search to begin)
Our technical library houses over 4,000 high-quality sponsored white papers, application notes, reference guides, use cases—all organized by company.
kdboyce
7/29/2010 2:08 PM EDT
National Semiconductor pioneered the audio subsystem category for mobile phones and other portable hand held products, and continues to innovate in that category.
Of particular note, the analog background noise suppression solution maintains the original voice quality with essentially zero latency as compared to DSP solutions which often have quirky artifacts in the resultant speech signal. This will result in very high MOS (Mean Opinion Score) for voice calls for phones using this type of product.
Sign in to Reply