LM4856 Integrated Audio Amplifier System
May 2004
LM4856
Integrated Audio Amplifier System
General Description
The LM4856 is an audio power amplifier system capable of
delivering 1.1W (typ) of continuous average power into a
mono 8鈩?bridged-tied load (BTL) with 1% THD+N and
60mW (typ) per channel of continuous average power into
stereo 32鈩?single-ended (SE) loads with 0.5% THD+N, us-
ing a 5V power supply.
The LM4856 features a 32 step digital volume control and
eight distinct output modes. The digital volume control and
output modes are programmed through a two-wire I
2
C com-
patible control interface, that allows flexibility in routing and
mixing audio channels.
The LM4856 is designed for cellular phone, PDA, and other
portable handheld applications. It delivers high quality output
power from a surface-mount package and requires only
eight external components.
The industry leading micro SMD package only utilizes 2mm
x 2.3mm of PCB space, making the LM4856 the most space
efficient audio sub system available today.
Key Specifications
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THD+N at 1kHz, 1.1W into 8鈩?BTL
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THD+N at 1kHz, 60mW into 32鈩?SE
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Single Supply Operation
1.0% (typ)
0.5% (typ)
2.6 to 5.0V
Features
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1.1W (typ) output power with 8鈩?mono BTL load
60mW (typ) output power with stereo 32鈩?SE loads
I
2
C programmable 32 step digital volume control
Eight distinct output modes
micro-SMD and LLP surface mount packaging
"Click and Pop" suppression circuitry
Thermal shutdown protection
Low shutdown current (0.1uA, typ)
Applications
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Moblie Phones
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PDAs
Typical Application
20060732
FIGURE 1. Typical Audio Amplifier Application Circuit
Boomer
廬
is a registered trademark of National Semiconductor Corporation.
漏 2004 National Semiconductor Corporation
DS200607
www.national.com