LM49352 Datasheet, PDF (1/4 Pages) Texas Instruments – Mono Class D Audio Codec Subsystem with Ground Referenced Headphone Amplifiers, Earpiece Driver, and Audio DSP

LM49352
PRODUCT BRIEF
PRELIMINARY
April 16, 2009
Mono Class D Audio Codec Subsystem with Ground
Referenced Headphone Amplifiers, Earpiece Driver, and
Audio DSP
1.0 General Description
The LM49352 is a high performance mixed signal audio sub-
system. The LM49352 includes a high quality stereo DAC, a
high quality stereo ADC, a stereo headphone amplifier, which
supports True Ground operation, a low EMI Class D loud-
speaker amplifier, and an earpiece speaker amplifier. It com-
bines advanced audio processing, conversion, mixing, and
amplification in the smallest possible footprint while extending
the battery life of feature rich portable devices.
The LM49352 features dual bi-directional I²S or PCM audio
interfaces and an I²C compatible interface for control. The
stereo DAC path features an SNR of 103dB with 24-bit 48 kHz
input. The headphone amplifier delivers 65mW_RMS (typ) to a
32Ω single-ended stereo load with less than 1% distortion
(THD+N) when HP_V_DD = 2.8V. The loudspeaker amplifier
delivers up to 970mW into an 8Ω load with less than 1% dis-
tortion when LS_V_DD = 4.2V.
The LM49352 employs advanced techniques to extend bat-
tery life, to reduce controller overhead, to speed development
time, and to eliminate click and pop artifacts. Boomer audio
power amplifiers are designed specifically for mobile devices
and require minimal PCB area and external components.
Notice: This document is not a full datasheet. For more
information regarding this product or to order samples
please contact your local National Semiconductor sales
office or visit http://www.national.com/support/dir.html
2.0 Applications
■ ^{Smart Phones}
■ ^{Mobile Phones and VOIP Phones}
■ ^{Portable GPS Navigator and Portable Gaming Devices}
■ ^{Portable DVD/CD/AAC/MP3/MP4 Players}
■ ^{Digital Cameras/Camcorders}
3.0 Key Specifications
■ ^{Class D Amplifier Efficiency}
■ ^P_EP ^{at A_V}_DD ^{= 3.3V, 32Ω, 1% THD}
■ ^P_HP ^{at HP_V}_DD ^{= 2.8V, Stereo 32Ω,}
1% THD
■ ^P_LS ^{at LS_V}_DD ^{= 5V, 8Ω, 1% THD}
93% (typ)
58mW (typ)
65mW/ch (typ)
1.4W (typ)
■ ^P_LS ^{at LS_V}_DD ^{= 4.2V, 8Ω, 1% THD}
■ ^P_LS ^{at LS_V}_DD ^{= 3.3V, 8Ω, 1% THD}
■ ^{SNR (Stereo DAC at 48kHz)}
■ ^{PSRR at 217 Hz, A_V}_DD ^{= 3.3V, (HP from}
AUX)
970mW (typ)
590mW (typ)
103dB (typ)
100dB (typ)
4.0 Features
■ ^{Ultra efficient, spread spectrum Class D loudspeaker}
amplifier that operates at 93% efficiency
■ ^{Low voltage, true ground headphone amplifier operation}
■ ^{High performance 103dB SNR stereo DAC}
■ ^{High performance 97dB SNR stereo ADC}
■ ^{Up to 96kHz stereo audio playback}
■ ^{Up to 48kHz stereo recording}
■ ^{Dual bidirectional I2S or PCM compatible audio interfaces}
■ ^{Read/write I2C compatible control interface}
■ ^{Flexible digital mixer with sample rate conversion}
■ ^{Sigma-delta PLL clock network that supports system}
clocks up to 50MHz including 13MHz, 19.2MHz, and
26MHz
■ ^{Dual stereo 5 band parametric equalizers}
■ ^{Cascadable DSP effects that allow stereo 10 band}
parametric equalization
■ ^{ALC/Limiter/Compressor on both DAC and ADC paths}
■ ^{Dedicated Earpiece Speaker Amplifier}
■ ^{Stereo auxiliary inputs and mono differential input}
■ ^{Differential microphone input with single-ended option}
■ ^{Automatic level control for digital audio inputs, mono}
differential input, microphone input, and stereo auxiliary
inputs
■ ^{Flexible audio routing from input to output}
■ ^{16 Step volume control for microphone with 2dB steps}
■ ^{32 Step volume control for auxiliary inputs in 1.5dB steps}
■ ^{4 Step volume control for class D loudspeaker amplifier}
■ ^{8 Step volume control for headphone amplifier}
■ ^{Micro-power shutdown mode}
■ ^{Available in the 3.3 x 3.3 mm 36 bump micro SMD package}
Boomer® is a registered trademark of National Semiconductor Corporation.
© 2009 National Semiconductor Corporation 300727
www.national.com