![background image](http://html1.mh-extra.com/html/texas-instruments/tpa3124d2/tpa3124d2_instructions-manual_1094286015.webp)
LOUT / ROUT
L
filter
C
filter
LOUT
L
filter
C
filter
L
filter
C
filter
ROUT
Power-Supply Decoupling, C
S
www.ti.com
........................................................................................................................................................................................................
SLOS578 – MAY 2008
Table 4. Recommended Filter Output Components
Output Configuration
Speaker Impedance (
Ω
)
Filter Inductor (
µ
H)
Filter Capacitor (nF)
4
22
680
Single Ended (SE)
8
33
220
Bridge Tied Load (BTL)
8
22
680
Figure 27. BTL Filter Configuration
Figure 28. SE Filter Configuration
The TPA3124D2 is a high-performance CMOS audio amplifier that requires adequate power-supply decoupling
to ensure that the output total harmonic distortion (THD) is as low as possible. Power-supply decoupling also
prevents oscillations for long lead lengths between the amplifier and the speaker. The optimum decoupling is
achieved by using two capacitors of different types that target different types of noise on the power-supply leads.
For higher-frequency transients, spikes, or digital hash on the line, a good low equivalent-series-resistance (ESR)
ceramic capacitor, typically 0.1
µ
F to 1
µ
F, placed as close as possible to the device V
CC
lead works best. For
filtering lower frequency noise signals, a larger aluminum electrolytic capacitor of 470
µ
F or greater placed near
the audio power amplifier is recommended. The 470-
µ
F capacitor also serves as local storage capacitor for
supplying current during large signal transients on the amplifier outputs. The PVCC terminals provide the power
to the output transistors, so a 470-
µ
F or larger capacitor should be placed on each PVCC terminal. A 10-
µ
F
capacitor on the AVCC terminal is adequate. These capacitors must be properly derated for voltage and
ripple-current rating to ensure reliability.
Copyright © 2008, Texas Instruments Incorporated
15
Product Folder Link(s):