LM4923_07 Datasheet, PDF (1/14 Pages) National Semiconductor (TI) – 1.1 Watt Fully Differential Audio Power Amplifier With Shutdown Select

December 17, 2007
LM4923 
1.1 Watt Fully Differential Audio Power Amplifier With
Shutdown Select
General Description
The LM4923 is a fully differential audio power amplifier pri-
marily designed for demanding applications in mobile phones
and other portable communication device applications. It is
capable of delivering 1.1 watt of continuous average 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
■ Improved PSRR at 217Hz
■ Power Output at 5.0V
@ 1% THD+N
■ Power Output at 3.3V
@ 1% THD+N
■ Shutdown Current
85dB(typ)
1.1W(typ)
400mW(typ)
0.1µA(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
■ ^{2.4 - 5.5V operation}
■ ^{No output coupling capacitors, snubber networks or}
bootstrap capacitors required
Applications
■ ^{Mobile phones}
■ ^PDAs
■ ^{Portable electronic devices}
Connection Diagrams
LQ Package
8 Pin LQ Marking
8 Pin MSOP Package
20071330
Top View
Order Number LM4923LQ
See NS Package Number LQB08A
20071302
X − Date Code
TT − Die Traceability
G − Boomer
B2 − LM4923LQ
Top View
200713a1
See Order Number LM4923MM
See NS Package Number MUA08A
Boomer® is a registered trademark of National Semiconductor Corporation.
© 2007 National Semiconductor Corporation 200713
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