February 1998
LM4832
Digitally Controlled Tone and Volume Circuit with Stereo
Audio Power Amplifier, Microphone Preamp Stage and
National 3D Sound
General Description
Key Specifications
The LM4832 is a monolithic integrated circuit that provides
volume and tone (bass and treble) controls as well as a ste-
reo audio power amplifier capable of producing 250 mW
(typ) into 8Ω or 90 mW (typ) into 32Ω with less than 1.0%
THD. In addition, a two input microphone preamp stage, with
volume control, capable of driving a 1 kΩ load is imple-
mented on chip.
n Output Power at 10% into:
8Ω
32Ω
350 mW(typ)
100 mW(typ)
n THD + N at 75 mW into
32Ω at 1 kHz
0.5%(max)
7 µV(typ)
n Microphone Input Referred
The LM4832 also features National’s 3D Sound circuitry
which can be externally adjusted via a simple RC network.
For maximum system flexibility, the LM4832 has an exter-
nally controlled, low-power consumption shutdown mode,
and an independent mute for power and microphone ampli-
fiers .
Boomer® audio integrated circuits were designed specifically
to provide high quality audio while requiring few external
components. Since the LM4832 incorporates tone and vol-
ume controls, a stereo audio power amplifier and a micro-
phone preamp stage, it is optimally suited to multimedia
monitors and desktop computer applications.
Noise
n Supply Current
13 mA(typ)
4 µA(max)
n Shutdown Current
Features
n Independent Left and Right Output Volume Controls
n Treble and Bass Control
n National 3D Sound
n I2C Compatible Interface
n Two Microphone Inputs with Selector
n Software Controlled Shutdown Function
Applications
n Multimedia Monitors
n Portable and Desktop Computers
Block Diagram
Connection Diagram
DS100014-2
Top View
Order Number LM4832N, LM4832M
See NS Package Number N28B for DIP
DS100014-1
FIGURE 1. LM4832 Block Diagram
See NS Package Number M28B for SOIC
Boomer® is a registered trademark of National Semiconductor Corporation.
© 1998 National Semiconductor Corporation
DS100014
www.national.com
NSC [ National Semiconductor ]
