LM4871 1.1W Audio Power Amplifier with Shutdown Mode
February 2000
LM4871
1.1W Audio Power Amplifier with Shutdown Mode
General Description
The LM4871 is a bridge-connected audio power amplifier ca-
pable of delivering typically 1.1W of continuous average
power to an 8Ω load with 0.5% (THD) from a 5V power sup-
ply.
Boomer audio power amplifiers were designed specifically to
provide high quality output power with a minimal amount of
external components. Since the LM4871 does not require
output coupling capacitors, bootstrap capacitors, or snubber
networks, it is optionally suited for low-power portable sys-
tems.
The LM4871 features an externally controlled, low-power
consumption shutdown mode, as well as an internal thermal
shutdown protection mechanism.
The unity-gain stable LM4871 can be configured by external
gain-setting resistors.
Key Specifications
n
THD at 1 kHz at 1W continuous
average output power into 8Ω
n
Output power at 10% THD+N
at 1 kHz into 8Ω
n
Shutdown Current
0.5% (max)
1.5W (typ)
0.6 µA (typ)
Features
n
No output coupling capacitors, bootstrap capacitors, or
snubber circuits are necessary
n
Small Outline or DIP packaging
n
Unity-gain stable
n
External gain configuration capability
n
Pin compatible with LM4861
Applications
n
Portable Computers
n
Desktop Computers
n
Low Voltage Audio Systems
Typical Application
Connection Diagram
Small Outline and DIP Package
DS100008-2
Top View
Order Number LM4871M or LM4871N
See NS Package Number M08A or N08E
DS100008-1
FIGURE 1. Typical Audio Amplifier Application Circuit
Boomer
®
is a registered trademark of National Semiconductor Corporation.
© 2000 National Semiconductor Corporation
DS100008
www.national.com
NSC [ NATIONAL SEMICONDUCTOR ]
