LM4908

10kV ESD Rated, Dual 120 mW Headphone Amplifier

General Description

The LM4908 is a dual audio power amplifier capable of

delivering 120mW per channel of continuous average power

into a 16

Ω load with 0.1% (THD+N) from a 5V power supply.

Boomer audio power amplifiers were designed specifically to

provide high quality output power with a minimal amount of

external components using surface mount packaging. Since

the LM4908 does not require bootstrap capacitors or snub-

ber networks, it is optimally suited for low-power portable

systems.

The unity-gain stable LM4908 can be configured by external

gain-setting resistors.

Key Specifications

continuous average output power

into 16

Ω

0.1% (typ)

continuous average output power

into 32

Ω

0.1% (typ)

at 1kHz into 32

Ω

75mW (typ)

Features

n

Up to 10kV ESD protection on all pins

n

MSOP, SOP, and LLP surface mount packaging

n

Switch on/off click suppression

n

Excellent power supply ripple rejection

n

Unity-gain stable

n

Minimum external components

Applications

n

Headphone Amplifier

n

Personal Computers

n

Portable electronic devices

Typical Application

20075201

*Refer to the Application Information Section for information concerning proper selection of the input and output coupling capacitors.

FIGURE 1. Typical Audio Amplifier Application Circuit

February 2004

© 2004 National Semiconductor Corporation

DS200752

www.national.com