Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 2
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
T H E R M A L D A T A
DB
44-P
IN
QSSOP P
ACKAGE
THERMAL RESISTANCE
-
JUNCTION TO AMBIENT
,
θ
JA
50
°
C/W
Junction Temperature Calculation: T
J
= T
A
+ (P
D
x
θ
JA
).
The
θ
JA
numbers are guidelines for the thermal performance of the device/pc-board
system. All of the above assume no ambient airflow.
P A C K A G E P I N O U T
1
22
23
44
LFAOUT
CPWM
RPWM
LMUTE
LEAOUT
LEAIN
VREF
CLOCK
GND
V25
LIN+
LIN-
LAMPOUT
RIN+
RIN-
RAMPOUT
SLEEP
STATUS
RMUTE
REAIN
REAOUT
RFAOUT
LFBK-
LFBK+
LISN
VDD
CN
PVDD
PGND
LN+
LP+
LP-
LN-
RN-
RP-
RP+
RN+
PGND
CP
PVDD
NC
RISN
RFBK+
RFBK-
DB P
ACKAGE
(Top View)
D E S C R I P T I O N
The stereo output controller is available in either an
LX1722 high power version (>65Wrms, 4
) with a supply
voltage range of 7V-25V or an LX1721 high fidelity
version (better SNR performance) with a supply voltage
range of 7V-15V. The current rating of the external
MOSFET’s, the available supply voltage, and speaker load
primarily limits the maximum output power. The amplifier
provides high fidelity performance and is designed to
operate over the full 20Hz to 20kHz audio band. Signal
distortion measurements yield
THD+N levels of 0.06%(1kHz, 1Wrms). Efficiency is
greater than 80% typical, which eliminates the need for
heatsinks in most applications. The AudioMAX solution
requires a single supply voltage, simplifying input power
requirements where a dual supply may not be available. To
minimize potential environmental noise issues and ease the
integration of the amplifier into a variety of applications,
features such as a balanced/differential audio input and a high
power supply rejection ratio help reduce the effects of noise
from the audio signal or power supply.
P
A
C
K
A
G
E
D
A
T
A