LM49321 Datasheet, PDF (1/45 Pages) National Semiconductor (TI) – Audio Sub-System with Stereo DAC, Mono Class AB Loudspeaker Amplifier, OCL/SE Stereo Headphone Output and RF Suppression

LM49321, LM49321RLEVAL
www.ti.com
SNAS457C – SEPTEMBER 2008 – REVISED MAY 2013
LM49321
Audio Sub-System with Stereo DAC, Mono Class
AB Loudspeaker Amplifier, OCL/SE Stereo Headphone Output and RF Suppression
Check for Samples: LM49321, LM49321RLEVAL
FEATURES
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•2 8-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
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 amplifier
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 capacitor-less
(OCL) or single-ended (SE) mode. It integrates the
audio amplifiers, volume control, mixer, and power
management control all into a single package. In
addition, the LM49321 routes and mixes the single-
ended stereo and differential 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: 520 mW (Typ)
• P_OUT HP, 32Ω, 3.3V, 1% THD+N: 36 mW (Typ)
• P_OUT Mono Earpiece, 32Ω, 1% THD+N: 55 mW
(Typ)
• Shutdown Current: 0.6 µA (Typ)
• SNR (DAC + Amplifier): 85 dB (Typ)
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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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