LM49321 Datasheet, PDF (1/42 Pages) National Semiconductor (TI) – Audio Sub-System with Stereo DAC, Mono Class AB Loudspeaker Amplifier, OCL/SE Stereo Headphone Output and RF Suppression

LM49321
August 31, 2009
Audio Sub-System with Stereo DAC, Mono Class AB
Loudspeaker Amplifier, OCL/SE Stereo Headphone Output
and RF Suppression
General Description
The LM49321 is an integrated audio sub-system designed for
mono voice, stereo music cell phones connecting to base
band processors with mono differential analog voice paths.
Operating on a 3.3V supply, it combines a mono speaker am-
plifier delivering 520mW into an 8Ω load, a stereo headphone
amplifier delivering 36mW per channel into a 32Ω load, and
a mono earpiece amplifier delivering 55mW into a 32Ω load.
The headphone amplifier can be configured for output capac-
itor-less (OCL) or single-ended (SE) mode. It integrates the
audio amplifiers, volume control, mixer, and power manage-
ment control all into a single package. In addition, the
LM49321 routes and mixes the single-ended stereo and dif-
ferential mono inputs into multiple distinct output modes. The
LM49321 features an I²S serial interface for full range audio
and an I²C or SPI compatible interface for control. The full
range music path features an SNR of 85dB with up to 192kHz
playback.
Boomer audio power amplifiers are designed specifically to
provide high quality output power with a minimal amount of
external components.
Key Specifications
■ P_OUT LS, 8Ω, 3.3V, 1% THD+N
■ P_OUT HP, 32Ω, 3.3V, 1% THD+N
■ P_OUT Mono Earpiece, 32Ω
1% THD+N
■ Shutdown current
■ SNR (DAC + Amplifier)
520mW (typ)
36mW (typ)
55mW (typ)
0.6µA (typ)
85dB (typ)
Features
■ ^{18-bit stereo DAC with up to 192kHz sampling rate}
■ ^{Multiple distinct output modes}
■ ^{Mono class AB speaker amplifier}
■ ^{Stereo OCL/SE headphone amplifier}
■ ^{Mono earpiece amplifier}
■ ^{Differential mono analog input}
■ ^{Single-ended analog inputs}
■ ^{Independent loudspeaker, headphone and mono earpiece}
volume controls
■ ^{I2C/SPI (selectable) compatible interface}
■ ^{Ultra low shutdown current}
■ ^{Click and Pop Suppression circuit}
Applications
■ ^{Cell Phones}
■ ^PDAs
■ ^{Laptop computers}
■ ^{Portable devices}
Boomer® is a registered trademark of National Semiconductor Corporation.
© 2009 National Semiconductor Corporation 300618
www.national.com