LM4928 Datasheet, PDF (1/20 Pages) National Semiconductor (TI) – 1.2 Watt Stereo Fully Differential Audio Amplifier with RF Suppression and Shutdown Low

February 2006
LM4928
1.2 Watt Stereo Fully Differential Audio Amplifier with RF
Suppression and Shutdown Low
General Description
The LM4928 is an stereo fully differential stereo audio power
amplifier primarily designed for demanding applications in
mobile phones and other portable communication devices. It
is capable of delivering 1.2 watts of continuous average
power to a 8Ω load with less than 1% distortion (THD+N)
from a 5V_DC power supply.
Boomer audio power amplifiers were designed specifically to
provide high quality output power with a minimal amount of
external components. The LM4928 does not require output
coupling capacitors or bootstrap capacitors, and therefore is
ideally suited for mobile phone and other low voltage appli-
cations where minimal power consumption is a primary re-
quirement.
The LM4928 features a low-power consumption shutdown
mode. To facilitate this, shutdown may be enabled by logic
low. Additionally, the LM4928 features an internal thermal
shutdown protection mechanism.
The LM4928 contains advanced pop & click circuitry which
eliminates noises which would otherwise occur during
turn-on and turn-off transitions.
Key Specifications
j Improved PSRR at 217Hz
90dB (typ)
j Output Power at 5.0V @ 1% THD+N (8Ω) 1.2W (typ)
j Output Power at 3.0V @ 1% THD+N (8Ω)400mW (typ)
j Shutdown Current
0.1µA (typ)
Features
n RF Suppression Circuitry
n Fully differential amplification
n Available in space-saving micro SMD and LLP packages
n Ultra low current shutdown mode
n Can drive capacitive loads up to 100pF
n Improved pop & click circuitry eliminates noises during
turn-on and turn-off transitions
n 2.4 - 5.5V operation
n No output coupling capacitors, snubber networks or
bootstrap capacitors required
Applications
n Mobile phones
n PDAs
n Portable electronic devices and accessories
Boomer^® is a registered trademark of National Semiconductor Corporation.
© 2006 National Semiconductor Corporation DS201600
www.national.com