Features
Spread Spectrum Class D architecture reduces EMI
Mono Class D 8Ω amplifier, 490 mW at 3.3V
OCL or AC-coupled headphone operation
33mW stereo headphone amplifier at 3.3V
115 mW earpiece amplifier at 3.3V
18-bit stereo DAC
16-bit mono ADC
8 kHz to 192 kHz stereo audio playback
8 kHz to 48 kHz mono recording
Bidirectional I
2S compatible audio interface
Bidirectional PCM compatible audio interface for Bluetooth transceivers
I
2S-PCM Bridge with sample rate conversion
Sigma-Delta PLL for operation from any clock at any sample rate
Digital 3D Stereo Enhancement
FIR filter programmability for simple tone control
Low power clock network operation if a 12 MHz or 13 MHz system clock is available
Read/write I
2C or SPI compatible control interface
Automatic headphone & microphone detection
Support for internal and external microphones
Automatic gain control for microphone input
Differential audio I/O for external cellphone module
Mono differential auxiliary output
Stereo auxiliary inputs
Differential microphone input for internal microphone
Flexible audio routing from input to output
32 Step volume control for mixers in 1.5 dB steps
16 Step volume control for microphone in 2 dB steps
Programmable sidetone attenuation in 3 dB steps
Two configurable GPIO ports
Multi-function IRQ output
Micro-power shutdown mode
Available in the 4 x 4 mm 49 bump micro SMDxt package
Description The LM49370 is an integrated audio subsystem that supports both analog and digital audio functions. The LM49370 includes a
high quality stereo DAC, a mono ADC, a stereo headphone amplifier, which supports output cap-less (OCL) or AC-coupled (SE)
modes of operation, a mono earpiece amplifier, and an ultra-low EMI spread spectrum Class D loudspeaker amplifier. It is designed
for demanding applications in mobile phones and other portable devices.
The LM49370 features a bi-directional I
2S interface and a bi-directional PCM interface for full range audio on either interface. The LM49370 utilizes an I
2C or SPI compatible interface for control. The stereo DAC path features an SNR of 85 dB with an 18-bit 48 kHz input. In SE
mode the headphone amplifier delivers at least 33 mWRMS to a 32Ω single-ended stereo load with less than 1% distortion (THD+N) when A_VDD = 3.3V. The mono earpiece amplifier delivers at least 115mWRMS to a 32Ω bridged-tied load with less than 1% distortion (THD+N) when A_VDD = 3.3V. The mono speaker amplifier delivers up to 490mW into an 8Ω load with less than 1% distortion when LS_VDD = 3.3V and up to 1.2W when
LS_VDD = 5.0V.
The LM49370 employs advanced techniques to reduce power consumption, to reduce controller overhead, to speed development time,
and to eliminate click and pop. Boomer audio power amplifiers were designed specifically to provide high quality output power
with a minimal amount of external components. It is therefore ideally suited for mobile phone and other low voltage applications
where minimal power consumption, PCB area and cost are primary requirements.
Key Specification
|
PHP (AC-COUP) (A_VDD = 3.3V, 32Ω, 1% THD)
|
33 mW
|
|
PHP (OCL) (A_VDD = 3.3V, 32Ω, 1% THD)
|
31 mW
|
|
PLS ( LS_VDD = 5V, 8Ω, 1% THD)
|
1.2 W
|
|
PLS (LS_VDD = 4.2V, 8Ω, 1% THD)
|
900 mW
|
|
PLS (LS_VDD = 3.3V, 8Ω, 1% THD)
|
490 mW
|
|
Shutdown Current
|
0.8 µA
|
|
PSRRLS (217 Hz, LS_VDD = 3.3V)
|
70 dB
|
|
SNRLS (AUX IN to Loudspeaker)
|
90 dB (typ)
|
|
SNRDAC (Stereo DAC to AUXOUT)
|
85 dB (typ)
|
|
SNRADC (Mono ADC from Cell Phone In)
|
90 dB (typ)
|
|
SNRHP (Aux In to Headphones)
|
98 dB (typ)
|
Applications
Smart phones
Mobile Phones and Multimedia Terminals
PDAs, Internet Appliances and Portable Gaming
Portable DVD/CD/AAC/MP3 Players
Digital Cameras/Camcorders
|
Also Recommended
| LM49352▲ | Lower Power Cusumption Headphone, Higher Output Power |
|
|
LM49352
