LM4831 Datasheet, PDF (1/12 Pages) National Semiconductor (TI) – Multimedia Computer Audio Chip

November 1998
LM4831
Multimedia Computer Audio Chip
General Description
The LM4831 is a monolithic integrated circuit that provides a
stereo three input mixer, two stereo input analog multiplexer,
a stereo line out and a dual 1W bridged audio power ampli-
fier. In addition, a low noise microphone preamp is included
on-chip.
The LM4831 is ideal for multimedia computers since it incor-
porates an input mixer, analog multiplexer, and configurable
stereo audio power amplifier, as well as a microphone
preamp stage. This combination allows for all of the analog
audio processing to be enclosed in a 44-pin TQFP package.
The LM4831 features an externally controlled, low-power
consumption shutdown mode, as well as both headphone
and docking station modes. To temporarily override the shut-
down mode and allow audio signals to be amplified, the
LM4831 provides four “beep” pins.
Key Specifications
n THD+N at 1W into 8Ω
n Microphone Input Referred Noise
n Supply Current - Bridged Mode
n Shutdown Current
0.6% (typ)
10µV (typ)
16mA (typ)
2µA (typ)
Features
n Stereo 1W audio power amplifier
n “Click and pop” suppression circuitry
n Stereo three input mixer
n Shutdown mode
n Multiple operating modes — bridged, single-ended and
docking station modes
n Internal mux for switching in/out external filter
n Beep circuitry for “wake-up” while in shutdown
n 44 Pin TQFP Packaging
Applications
n Portable and Desktop Computers
Block Diagram
Connection Diagram
DS100057-1
FIGURE 1. LM4831 Block Diagram
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© 1998 National Semiconductor Corporation DS100057
Top View
Order Number LM4831VF
See NS Package Number VEJ44A
DS100057-3
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