Datasheet

REF
CPGND
I
2
C
INTERFACE
I 2
C
BUS
C
S
C
S
V
DD
MCLK
I 2
S _
CLK
I 2
S _
SDI
I 2
S _
WS
SDA
SCL
DGND
HPR
HPL
LSGND
RLS-
RLS+
LLS
-
LLS
+
LSV
DD
LSV
DD
V
DD
HPS
C
REF
CLASS D
CLASS D
CLASS
AB
CLASS
AB
INL
INR
24
-
BIT
STEREO
DAC
32
-
STEP
VOLUME
CONTROL
CHARGE PUMP
C
1
C
1P
C
1N
HPV
DD
HPGND
C
S
CPV
DD
CPV
DD
C
2
HPV
SS
L
R
OSCILLATOR
HPV
DD
I
2
S
INTERFACE
3
D
PROCESSOR
C
S
BYPASS
C
BYPASS
GND
IOV
DD
DV
DD
1 .
8 V to
4
. 5
V
2
. 7 V to
4 . 5
V
IOV
DD
DV
DD
2
. 7
V to
5 .
5 V
LM49450
SNAS440D –FEBRUARY 2008–REVISED MAY 2013 www.ti.com
DESCRIPTION (CONTINUED)
The filterless Class D amplifiers deliver 1.25W/channel into an 8Ω load with <1% THD+N with a 5V supply. The
LM49450 offers two logic selectable modulation schemes, fixed frequency mode, and an EMI reducing spread
spectrum mode. The 36mW/channel headphone drivers feature TI’s ground referenced architecture that creates
a ground-referenced output from a single supply, eliminating the need for bulky and expensive DC-blocking
capacitors, saving space and minimizing system cost. A headphone sense input (HPS) automatically detects the
presence of a headphone, and configures the device accordingly.
The LM49450 stereo, 24-bit DAC supports a wide range of sample rates (including 192kHz, 96kHz, 48kHz, and
44.1kHz). The digital audio signal path features better than 100dB SNR, and low 0.05% THD+N when measured
at the headphone outputs. The flexible 3-wire I
2
S interface supports left or right justified audio data.
The LM49450 features separate 32-step volume control for the headphones and speaker outputs. 3D
enhancement, mode selection, shutdown control, and volume are controlled through an I
2
C compatible interface.
Output short circuit and thermal overload protection prevent the device from being damaged during fault
conditions. Superior click and pop suppression eliminates audible transients on power-up/down and during
shutdown. The LM49450 is available in a space saving 32-pin WQFN package.
Typical Application
Figure 1. Typical Audio Amplifier Application Circuit
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