LM4851LQ

Manufacturer Part NumberLM4851LQ
DescriptionIntegrated Audio Amplifier System
ManufacturerNational Semiconductor
LM4851LQ datasheet
 


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LM4851
Integrated Audio Amplifier System
General Description
The LM4851 is an audio power amplifier system capable of
delivering 1.1W (typ) of continuous average power into a
mono 8Ω bridged-tied load (BTL) with 1% THD+N and
115mW (typ) per channel of continuous average power into
stereo 32Ω BTL loads with 0.5% THD+N, using a 5V power
supply.
The LM4851 features a 32 step digital volume control and
eight distinct output modes. The digital volume control and
output modes are programmed through a three-wire SPI
serial control interface, that allows flexibility in routing and
mixing audio channels. The LM4851 has 3 inputs: one pair
for a two-channel stereo signal and the third for a single-
channel mono input.
The LM4851 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 five
external components.
The industry leading micro SMD package utilizes only 2mm
x 2.3mm of PCB space, making the LM4851 the most space
efficient audio sub system available today.
Typical Application
FIGURE 1. Typical Audio Amplifier Application Circuit
Boomer
®
is a registered trademark of National Semiconductor Corporation.
© 2002 National Semiconductor Corporation
Key Specifications
n THD+N at 1kHz, 1.5W into 4Ω BTL (LQ)
n THD+N at 1kHz, 1.1W into 8Ω BTL
n THD+N at 1kHz, 115mW into 32Ω BTL
n Single Supply Operation
Features
n Mono 1.1W (typ) and stereo 115mW (typ) output
n SPI programmable 32 step digital volume control
(-40.5dB to +6dB)
n Eight distinct SPI programmable output modes
n micro-SMD and LLP surface mount packaging
n “Click and pop” suppression circuitry
n Thermal shutdown protection
n Low shutdown current (0.1µA, typ)
Applications
n Mobile phones
n PDAs
DS200408
December 2002
1% (typ)
1% (typ)
0.5% (typ)
2.6 to 5.0V
20040831
www.national.com

LM4851LQ Summary of contents