LM4731 Stereo 25W Audio Power Amplifier with Mute and Standby Modes
July 2003
LM4731
Stereo 25W Audio Power Amplifier with Mute and
Standby Modes
General Description
The LM4731 is a stereo audio amplifier capable of delivering
typically 25W per channel of continuous average output
power into a 4鈩?or 8鈩?load with less than 10% THD+N from
20Hz - 20kHz.
Each amplifier has an independent smooth transition fade-
in/out mute and a power conserving standby mode which
can be controlled by external logic.
The LM4731 has short circuit protection and a thermal shut
down feature that is activated when the die temperature
exceeds 150藲C. The LM4731 also has a under voltage lock
out feature for click and pop free power off and on.
The LM4731 has a wide operating supply range from +/-10V
- +/-28V allowing for lower cost unregulated power supplies
to be used.
Key Specifications
j
Output Power into 4鈩?or 8鈩? 10% THD+N
j
THD+N at 1kHz with 2 x 1W into 8鈩?/div>
j
Mute Attenuation
j
PSRR with f
RIPPLE
= 120Hz,
25W (typ)
0.02% (typ)
85dB (typ)
50dB (typ)
18V/碌s (typ)
4.8mA (typ)
V
RIPPLE
= 1V
RMS
j
Slew Rate
j
Standby Current (+/-22V)
Features
n
Minimal amount of external components necessary
n
Quiet fade-in/out mute mode
n
Low current Standby-mode
Applications
n
n
n
n
n
Audio
Audio
Audio
Audio
Audio
amplifier
amplifier
amplifier
amplifier
amplifier
for
for
for
for
for
high-end stereo TVs
component stereo
compact stereo
PC satellite speaker systems
self powered speakers
Connection Diagrams
Plastic Package
TO-220 Top Marking (Note 12)
20060375
20060352
Top View
Non-Isolated Package
Order Number LM4731TA
See NS Package Number TA15A
Top View
U - Wafer Fab Code
Z - Assembly Plant Code
XY - Date Code
TT - Die Traceability
LM4731TA - LM4731TA
漏 2003 National Semiconductor Corporation
DS200603
www.national.com
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