LM4995

1.3 Watt Audio Power Amplifier

General Description

The LM4995 is an audio power amplifier primarily designed

for demanding applications in mobile phones and other por-

table communication device applications. It is capable of

delivering 1.3W of continuous average power to an 8

Ω 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 LM4995 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 LM4995 features a low-power consumption shutdown

mode, which is achieved by driving the shutdown pin with

logic low. Additionally, the LM4995 features an internal ther-

mal shutdown protection mechanism.

The LM4995 contains advanced pop & click circuitry which

eliminates noise which would otherwise occur during turn-on

and turn-off transitions.

The LM4995 is unity-gain stable and can be configured by

external gain-setting resistors.

Key Specifications

75dB

Ω

1.3W (typ)

Ω

625mW (typ)

0.01µA (typ)

Features

n

Available in space-saving 0.4mm pitch µSMD package

n

Ultra low current shutdown mode

n

BTL output can drive capacitive loads

n

Improved pop & click circuitry eliminates noise 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

Unity-gain stable

n

External gain configuration capability

Applications

n

Mobile Phones

n

PDAs

n

Portable electronic devices

Typical Application

201599D3

FIGURE 1. Typical Audio Amplifier Application Circuit

April 2006

© 2006 National Semiconductor Corporation

DS201599

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