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 I
2S or PCM compatible audio interfaces
|
| • | Read/write I
2C 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 |
Description The LM49352 is a high performance mixed signal audio subsystem. 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 loudspeaker amplifier, and
an earpiece speaker amplifier. It combines 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 I
2S or PCM audio interfaces and an I
2C compatible interface for control. The stereo DAC path features an SNR of 103dB with 24-bit 48 kHz input. The headphone amplifier
delivers 65mWRMS (typ) to a 32Ω single-ended stereo load with less than 1% distortion (THD+N) when HP_VDD = 2.8V. The loudspeaker amplifier delivers up to 970mW into an 8Ω load with less than 1% distortion when LS_VDD = 4.2V.
The LM49352 employs advanced techniques to extend battery 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
Key Specification
|
Class D Amplifier Efficiency
|
93% (typ)
|
|
PEP at A_VDD = 3.3V, 32Ω, 1% THD
|
58mW (typ)
|
|
PHP at HP_VDD = 2.8V, Stereo 32Ω,
1% THD
|
65mW/ch (typ)
|
|
PLS at LS_VDD = 5V, 8Ω, 1% THD
|
1.4W (typ)
|
|
PLS at LS_VDD = 4.2V, 8Ω, 1% THD
|
970mW (typ)
|
|
PLS at LS_VDD = 3.3V, 8Ω, 1% THD
|
590mW (typ)
|
|
SNR (Stereo DAC at 48kHz)
|
103dB (typ)
|
|
PSRR at 217 Hz, A_VDD = 3.3V, (HP from AUX)
|
100dB (typ)
|
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 |
|
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