Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 1
Copyright
2000
Rev. 0.1b,2001-09-19
W
M
.
C
AudioMAX
LX1721 / 1722
Class-D Stereo Power Amplifier Controller
P
RELIMINARY
L I N F I N I T Y D I V I S I O N
D E S C R I P T I O N
The LX1721/1722 is a monolithic high
performance Class-D stereo controller IC
designed for high efficiency or space
constrained audio requirements such as
portable or battery operated products,
automotive amplifiers, and multi-channel
multimedia computer and video game
applications. This high frequency, full
audio
bandwidth
amplifier controller offers dramatically
improved performance over Linfinity’s
previous generation amplifier products.
Enhancements include higher output
power, better SNR, lower noise floor, and
reduced THD. Combined with output
power MOSFET’s and an output filter, the
LX1721/1722 is a complete Class-D audio
solution.
IMPORTANT:
For the most current data, consult
MICROSEMI
’s website:
http://www.microsemi.com
switching
power
A complete audio amplifier module is
available to quickly evaluate the LX1721
or LX1722 stereo controller. Simply
connect the amplifier to the power source,
audio signal, and speakers. Reference
designs support a variety of requirements
including
multi
subwoofers, satellite / subwoofer com-
binations and various speaker loads (2
,
4
, 8
). The versatile amplifier solution
can easily be adjusted for frequency
response, optimized for efficiency and
performance, or designed to minimize
PCB area and component count. The
LX1721/1722 is available in a space
saving 44-pin QSOP package.
(Continued Next Page)
channel
systems,
P R O D U C T H I G H L I G H T
LX1722
Stereo
FETs
FETs
LX1711
Mono
IN +
IN -
FETs
IN +
IN -
IN +
IN -
CLOCK
Left
Right
Subwoofer
2
, 4
, 8
Channel
1
Channel 2
Channel 3
7V - 25V
2.1 Audio Amplifier
Configuration
Output Power vs. Supply Voltage
1kHz, 4
, THD+N=1%
K E Y F E A T U R E S
!
Integrated Switching Class-D
Stereo Controller IC
!
Full 20Hz-20kHz Audio
Bandwidth
!
High Fidelity (LX1721) Or
High Power (LX1722)
Versions Available
!
Single Supply Operation
!
THD+N <0.06% Typical
(1Wrms, 1kHz, 4
)
!
Maximum Efficiency 80%-
85%
!
Output Power >60Wrms per
Channel (LX1722, 4
, 1%
THD+N)
!
PSRR –70dB Typical
!
Differential Input To Minimize
Noise Effects
!
Supports Multi-Channel
Systems
!
Complete LXE1721or
LXE1722 Amplifier Evaluation
Module Available
!
44-Pin QSOP Package
A P P L I C A T I O N S
!
Multimedia Speakers
!
Surround Sound Game
Systems
!
Notebook Computers
!
Desktop Computers
!
Automotive Amplifiers And
Head units
!
Battery Operated Equipment
(Megaphone, Public Address
System)
!
Portable Audio (Boom Box)
!
Wireless Speakers
!
High Power Subwoofer
!
Automotive Audio Systems
!
Home Theatre
P A C K A G E O R D E R I N F O
T
J
(
°
C)
V
DD
DB
Plastic QSOP
44-Pin
LX1721CDB
LX1722CDB
0 to 70
0 to 70
7V – 15V
7V – 25V
Note: Available in Tape & Reel.
Append the letter “T” to the part number. (i.e. LX1722CDBT)
L
X
1
7
2
1
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2
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