LM4927

2.5 Watt Fully Differential Audio Power Amplifier With

Shutdown

General Description

The LM4927 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 2.5 watts of continuous

average power to a 4

Ω load with less than 10% 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 LM4927 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 LM4927 features a low-power consumption shutdown

mode. To facilitate this, Shutdown may be enabled by logic

low. Additionally, the LM4927 features an internal thermal

shutdown protection mechanism.

The LM4927 contains advanced pop & click circuitry which

eliminates noises which would otherwise occur during

turn-on and turn-off transitions.

Key Specifications

85dB (typ)

Ω)

2.5W (typ)

550mW (typ)

0.1µA (typ)

Features

n

Fully differential amplification

n

Available in space-saving micro-array 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

Typical Application

20152529

FIGURE 1. Typical Audio Amplifier Application Circuit

April 2006

© 2006 National Semiconductor Corporation

DS201525

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