LM4923 Datasheet, PDF (1/12 Pages) National Semiconductor (TI) – 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 8Ω 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)
0.1µA(typ)
Features
n Fully differential amplification
n Available in space-saving LLP package
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
Connection Diagrams
LQ Package
8 Pin LQ Marking
20071330
Top View
Order Number LM4923LQ
See NS Package Number LQB08A
20071302
X − Date Code
TT − Die Traceability
G − Boomer
B2 − LM4923LQ
Boomer^® is a registered trademark of National Semiconductor Corporation.
© 2004 National Semiconductor Corporation DS200713
www.national.com