January 2000
LM4663
2 Watt Stereo Class D Audio Power Amplifier with Stereo
Headphone Amplifier
%
83 (typ)
n Efficiency at 2 Watt into 4Ω
General Description
%
n Efficiency at 250mW into 4Ω
n Total quiescent power supply current
n Total shutdown power supply current
n THD+N 1kHz, 20mW, 32Ω (Headphone)
n Single supply range
69 (typ)
The LM4663 is a fully integrated single supply, high effi-
ciency Class D audio power amplifier solution. The LM4663
utilizes a continuous time delta-sigma modulation technique
that lowers output noise and THD when compared to con-
ventional pulse width modulators.
22mA (typ)
2µA (typ)
%
0.15 (typ)
4.5V to 5.5V
The LM4663 also features a stereo headphone amplifier that
Features
%
delivers 80mW into a 32Ω headset with less than 0.5 THD.
The LM4663 has two stereo inputs that can be selected to
drive either the headphone amplifier or the Class D amplifier.
All amplifiers are protected with thermal shutdown.
n Delta-sigma modulator.
n Two stereo input selector.
n “Click and pop” suppression circuitry.
n Micropower shutdown mode.
In standby mode, the LM4663 draws an extremely low 2µA
supply current. With a 4Ω load, the IC’s efficiency for a
n 24 lead TSSOP package (No heatsink required).
n Stereo headphone amplifier.
%
%
250mW power level is 69 , reaching 83 at a power level
of 2W. The IC features click and pop reduction circuitry that
minimizes audible popping during device turn-on and
turn-off. The LM4663 is available in a 24-lead TSSOP pack-
age, ideal for portable and desktop computer applications.
Applications
n Portable computers
n Desktop computers
n Multimedia Monitors
Key Specifications
=
%
n PO at THD+N 1
2.1W (typ)
n THD+N at 1kHz at 1 Watt into 4Ω (Power
%
Amp)
0.2 (typ)
Block Diagram
Connection Diagram
TSSOP Package
DS101269-2
Top View
Order Number LM4663MT
See NS Package Number MTC24
(TSSOP Package)
DS101269-1
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© 2000 National Semiconductor Corporation
DS101269
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