LM4930_04 Datasheet, PDF (1/35 Pages) National Semiconductor (TI) – Audio Subsystem with Stereo Headphone & Mono Speaker Amplifiers

September 2004
LM4930
Audio Subsystem with Stereo Headphone & Mono
Speaker Amplifiers
General Description
The LM4930 is an integrated audio subsystem that supports
voice and digital audio functions. The LM4930 includes a
high quality I²S input stereo DAC, a voice band codec, a
stereo headphone amplifier and a high-power mono speaker
amplifier. It is primarily designed for demanding applications
in mobile phones and other portable devices.
The LM4930 features an I²S serial interface for full range
audio, a 16-bit PCM bi-directional serial interface for the
voice band codec and an two-wire interface for control. The
full range music path features an SNR of 86dB with a 16-bit
48kHz input. The stereo DAC can also be used while the
voice codec is in use. The headphone amplifier delivers
25mW_RMS to a 32Ω single-ended stereo load with less than
0.5% distortion (THD+N) when AV_DD = 3V. The mono
speaker amplifier delivers up to 330mW into an 8Ω load with
less than 1% distortion when AV_DD = 3V.
The LM4930 employs advanced techniques to reduce power
consumption, to reduce controller overhead and to eliminate
click and pop. Boomer audio power amplifiers were de-
signed 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 appli-
cations where minimal power consumption is a primary re-
quirement.
Key Specifications
j P_{LS OUT} at AV_DD = 5.0V, 8Ω
1% THD+N
j P_{LS OUT} at AV_DD = 3.0V, 8Ω
1% THD+N
j P_{H/P OUT} at AV_DD = 3.0V, 32Ω
0.5% THD+N
j Supply voltage range
DV_DD (Note 8)
AV_DD (Note 8)
j Total shutdown current
j PSRR at 217Hz, AV_DD = 3V
1W (typ)
330mW (typ)
25mW (typ)
2.6V to 4.5V
2.6V to 5.5V
2µA (typ)
50dB (typ)
Features
n 16-bit resolution 48kHz stereo DAC
n 16-bit resolution 8kHz voice codec
n I²S digital audio data serial interface
n Two-wire serial control interface
n PCM voice audio data serial interface
n 25mW/channel stereo headphone amplifier
n 330mW mono 8Ω amplifier (at AV_DD = 3.0V)
n 32-step volume control for audio output amplifiers
n No snubber networks or bootstrap capacitors are
required by the headphone or hands-free amplifiers
n Digital sidetone generation with adjustable attenuation
n Gain controllable headphone amp, mono BTL amp, mic
preamp
n Available in the 36–bump micro SMD and 44–lead LLP
packages
Applications
n Mobile Phones
n Mobile/low power audio appliances
n PDAs
Boomer^® is a registered trademark of National Semiconductor Corporation.
© 2004 National Semiconductor Corporation DS200720
www.national.com