LM4881 Datasheet, PDF (1/11 Pages) National Semiconductor (TI) – Dual 200 mW Headphone Amplifier with Shutdown Mode

September 1997
LM4881
Dual 200 mW Headphone Amplifier with Shutdown Mode
General Description
The LM4881 is a dual audio power amplifier capable of deliv-
ering 200 mW of continuous average power into an 8Ω load
with 0.1% (THD) 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 LM4881 does not require bootstrap capacitors or snub-
ber networks, it is optimally suited for low-power portable
systems.
The LM4881 features an externally controlled, low power
consumption shutdown mode which is virtually clickless and
popless, as well as an internal thermal shutdown protection
mechanism.
The unity-gain stable LM4881 can be configured by external
gain-setting resistors.
Key Specifications
n THD at 1 kHz at 125 mW
continuous average output
power into 8Ω
n THD at 1 kHz at 75 mW continuous
average output power into 32Ω
n Output power at 10% THD+N
at 1 kHz into 8Ω
n Shutdown Current
0.1% (max)
0.02% (typ)
300 mW (typ)
0.7 µA (typ)
Features
n MSOP surface mount packaging
n Unity-gain stable
n External gain configuration capability
n Thermal shutdown protection circuitry
n No bootstrap capacitors, or snubber circuits are
necessary
Applications
n Headphone Amplifier
n Personal Computers
n Microphone Preamplifier
Typical Application
Connection Diagrams
MSOP Package
DS100005-2
SOP and DIP Package
DS100005-1
*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
DS100005-38
Top View
Order Number LM4881MM, LM4881M, or LM4881N
See NS Package Number MUA08A, M08A, or N08E
Boomer^® is a registered trademark of National Semiconductor Corporation.
© 1999 National Semiconductor Corporation DS100005
www.national.com