Analog audio subsystem integrates noise reduction
Suited for use in smart phones and full-featured phones, the LM49155 analog audio subsystem is offered as the first of its kind to integrate noise reduction. The part offers the lowest power consumption, consuming only 3.7 mA of quiescent current for the earpiece amplifier and microphone amplifier signal path. In addition it improves the talker’s voice-signal-to-background-noise ratio while retaining natural speech quality.
The LM49155 provides uplink noise suppression and downlink SNR enhancement in a 36-bump micro SMD package measuring 3.4 x 3.4 mm. The subsystem includes a 1.35-W Class D speaker driver with automatic level control (ALC), ground-referenced headphone amplifier with click-pop suppression, and mixing and volume control.
The part preserves uplink near-field voice signals within close range, while rejecting acoustic noise more than 0.5 m away from the microphones. In addition, the LM49155 provides continuous downlink signal adjustments so the caller’s voice is always clearly heard regardless of the listener’s environment. ($2.25 each in 1,000 — available now.)
National Semiconductor , Santa Clara , CA
Sales 800-272-9959
Advertisement
Learn more about National Semiconductor
