LM4810

Dual 105mW Headphone Amplifier with Active-High

Shutdown Mode

General Description

The LM4810 is a dual audio power amplifier capable of

delivering 105mW 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. Since the LM4810 does not require

bootstrap capacitors or snubber networks, it is optimally

suited for low-power portable systems.

The unity-gain stable LM4810 can be configured by external

gain-setting resistors.

The LM4810 features an externally controlled, active-high,

micropower consumption shutdown mode, as well as an

internal thermal shutdown protection mechanism.

Key Specifications

n

THD+N at 1kHz, 105mW continuous average power into

16

Ω

0.1% (typ)

n

THD+N at 1kHz, 70mW continuous average power into

32

Ω

0.1% (typ)

n

Shutdown Current

0.4µA (typ)

Features

n

Active-high shutdown mode

n

LLP, MSOP, and SO surface mount packaging

n

"Click and Pop" suppression circuitry

n

Low shutdown current

n

No bootstrap capacitors required

n

Unity-gain stable

Applications

n

Cellular Phones

n

Personal Computers

n

Microphone Preamplifier

n

PDA’s

Typical Application

20008901

*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

November 2002

© 2002 National Semiconductor Corporation

DS200089

www.national.com