LM4923 1.1 Watt Fully Differential Audio Power Amplifier With Shutdown Select
July 2004
LM4923
1.1 Watt Fully Differential Audio Power Amplifier With
Shutdown Select
General Description
The LM4923 is a fully differential audio power amplifier
primarily designed for demanding applications in mobile
phones and other portable communication device applica-
tions. It is capable of delivering 1.1 watt of continuous aver-
age power to an 8鈩?BTL 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 LM4923 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 LM4923 features a low-power consumption shutdown
mode. To facilitate this, Shutdown may be enabled by logic
low. Additionally, the LM4923 features an internal thermal
shutdown protection mechanism.
The LM4923 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
j
Power Output at 5.0V
@
1% THD+N
j
Power Output at 3.3V
@
1% THD+N
j
Shutdown Current
85dB(typ)
1.1W(typ)
400mW(typ)
0.1碌A(typ)
Features
Fully differential amplification
Available in space-saving LLP package
Ultra low current shutdown mode
Can drive capacitive loads up to 100pF
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
n
n
n
n
n
Applications
n
Mobile phones
n
PDAs
n
Portable electronic devices
Connection Diagrams
LQ Package
8 Pin LQ Marking
20071302
20071330
Top View
Order Number LM4923LQ
See NS Package Number LQB08A
X 鈭?Date Code
TT 鈭?Die Traceability
G 鈭?Boomer
B2 鈭?LM4923LQ
Boomer
庐
is a registered trademark of National Semiconductor Corporation.
漏 2004 National Semiconductor Corporation
DS200713
www.national.com