LM4871_03 Datasheet, PDF (1/16 Pages) National Semiconductor (TI) – 3W Audio Power Amplifier with Shutdown Mode

January 2003
LM4871
3W Audio Power Amplifier with Shutdown Mode
General Description
The LM4871 is a mono bridged audio power amplifier ca-
pable of delivering 3W of continuous average power into a
3Ω load with less than 10% THD when powered by a 5V
power supply (Note 1). To conserve power in portable appli-
cations, the LM4871’s micropower shutdown mode (I_Q =
0.6µA, typ) is activated when V_DD is applied to the SHUT-
DOWN pin.
Boomer audio power amplifiers are designed specifically to
provide high power, high fidelity audio output. They require
few external components and operate on low supply volt-
ages from 2.0V to 5.5V. Since the LM4871 does not require
output coupling capacitors, bootstrap capacitors, or snubber
networks, it is ideally suited for low-power portable systems
that require minimum volume and weight.
Additional LM4871 features include thermal shutdown pro-
tection, unity-gain stability, and external gain set.
Note 1: An LM4871LD that has been properly mounted to a circuit board will
deliver 3W into 3Ω (at 10% THD). The other package options for the LM4871
will deliver 1.5W into 8Ω (at 10% THD). See the Application Information
sections for further information concerning the LM4871LD, LM4871MM,
LM4871M, and the LM4871N.
Key Specifications
n PO at 10% THD+N, 1kHz
n LM4871LD: 3Ω , 4Ω loads
3W (typ), 2.5W (typ)
n All other LM4871 packages: 8Ω load
1.5W (typ)
n Shutdown current
0.6µA (typ)
n Supply voltage range
2.0V to 5.5V
n THD at 1kHz at 1W continuous average output power
into 8Ω
0.5% (max)
Features
n No output coupling capacitors, bootstrap capacitors, or
snubber circuits required
n Unity-gain stable
n LLP, MSOP, SO, or DIP packaging
n External gain configuration capability
n Pin compatible with the LM4861
Applications
n Portable computers
n Desktop computers
n Low voltage audio systems
Connection Diagrams
MSOP, Small Outline, and DIP Package
LLP Package
10000802
Top View
Order Number LM4871MM, LM4871M, or LM4871N
See NS Package Number MUA08A, M08A, or N08E
10000839
Top View
Order Number LM4871LD
See NS Package Number LDC08A
Boomer^® is a registered trademark of National Semiconductor Corporation.
© 2004 National Semiconductor Corporation DS100008
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