LM4864 300 mW Audio Power Amplifier with Shutdown Mode
September 1999
LM4864
300 mW Audio Power Amplifier with Shutdown Mode
General Description
The LM4864 is a bridged audio power amplifier capable of
delivering 300 mW of continuous average power into an 8Ω
load with 1% (THD) from a 5V power supply.
Boomer
®
audio power amplifiers were designed specifically
to provide high quality output power from a low supply volt-
age while requiring a minimal amount of external compo-
nents. Since the LM4864 does not require output coupling
capacitors, bootstrap capacitors or snubber networks, it is
optimally suited for low-power portable applications.
The LM4864 features an externally controlled, low power
consumption shutdown mode, and thermal shutdown protec-
tion.
The closed loop response of the unity-gain stable LM4864,
can be configured by external gain-setting resistors. The de-
vice is available in multiple package types to suit various ap-
plications.
Key Specifications
n
THD at 1 kHz at 300 mW continuous
average output power into 8Ω
n
THD at 1 kHz at 300 mW continuous
average output power into 16Ω
n
Shutdown current
1.0% (max)
1.0% (max)
0.7 µA (typ)
Features
n
MSOP, SOP, and DIP packaging
n
No output coupling capacitors, bootstrap capacitors, or
snubber circuits are necessary
n
Thermal shutdown protection circuitry
n
Unity-gain stable
n
External gain configuration capability
Applications
n
Cellular Phones
n
Personal Computers
n
General Purpose Audio
Typical Application
Connection Diagram
MSOP, SOP, and DIP Package
DS012607-2
Top View
Order Number LM4864MM,
LM4864M or LM4864N
See NS Package Number MUA08A,
M08A or N08E
DS012607-1
FIGURE 1. Typical Audio Amplifier Application Circuit
Boomer
®
is a registered trademark of National Semiconductor Corporation.
© 1999 National Semiconductor Corporation
DS012607
www.national.com
NSC [ NATIONAL SEMICONDUCTOR ]
