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

Ω BTL load with less than 1% distortion

(THD+N) from a 5V

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

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

July 2004

© 2004 National Semiconductor Corporation

DS200713

www.national.com