LM4811 Dual 105mW Headphone Amplifier with Digital Volume Control and Shutdown Mode
December 2002
LM4811
Dual 105mW Headphone Amplifier with Digital Volume
Control and Shutdown Mode
General Description
The LM4811 is a dual audio power amplifier capable of
delivering 105mW per channel of continuous average power
into a 16Ω 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 LM4811 does not require
bootstrap capacitors or snubber networks, it is optimally
suited for low-power portable systems.
The LM4811 features a digital volume control that sets the
amplifier’s gain from +12dB to −33dB in 16 discrete steps
using a two−wire interface.
The unity-gain stable LM4811 also features an externally
controlled, active-high, micropower consumption shutdown
mode. It also has an internal thermal shutdown protection
mechanism.
Key Specifications
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THD+N at 1kHz, 105mW continuous average output
power into 16Ω
0.1% (typ)
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THD+N at 1kHz, 70mW continuous average power into
32Ω
0.1% (typ)
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Shutdown Current
0.3µA (typ)
Features
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Digital volume control range from +12dB to −33dB
LD and MSOP surface mount packaging
"Click and Pop" suppression circuitry
No bootstrap capacitors required
Low shutdown current
Applications
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Cellular Phones
MP3, CD, DVD players
PDA’s
Portable electronics
Connection Diagrams
MSOP Package
LD Package
20006102
Top View
Order Number LM4811MM
See NS Package Number MUB10A
20006162
Top View
Order Number LM4811LD
See NS Package Number LDA10A
Boomer
®
is a registered trademark of National Semiconductor Corporation.
© 2002 National Semiconductor Corporation
DS200061
www.national.com
NSC [ NATIONAL SEMICONDUCTOR ]
