Texas Instruments DEM-DAI3793A User Manual
www.ti.com
5.4.3.1
LC Low-Pass Filter
Note (1): Same configuration at SPORN/SPORP
SPOL
SPOR
J3
J4
Snubber Circuit
LC LPF
SPOLN
SPOLP
L1 22 H
m
L2 22 H
m
C11
2.2 F
m
C12
2.2 F
m
C9
0.82 F
m
C8
0.82 F
m
R6
330W
R5
330W
R
8
8
L
W
Audio
Analyzer
Differential
Input
J3
TP2
TP1
+
-
f =
C
»
37.5 [kHz]
2
p
´
´
LC
1
(1)
Measurements for Dynamic Characteristics
Daughter Card #2 provides an LC low-pass filter (LPF) to obtain a clean analog signal from the
pulse-width modulated (PWM) output of the speaker output. This configuration is shown in
pulse-width modulated (PWM) output of the speaker output. This configuration is shown in
.
Additionally, a snubber circuit is inserted into the signal line to achieve the best output power performance
by suppressing ringing in the PWM pulse; however, a snubber circuit will have negligible effects in the end
system.
by suppressing ringing in the PWM pulse; however, a snubber circuit will have negligible effects in the end
system.
Figure 5-7. Speaker Output Filter Configuration
Evaluation and Measurements
58
SBAU127 – July 2007