TPA3131D2 Datasheet, PDF (23/31 Pages) Texas Instruments – 4W, 25W Filter-Free Class-D Stereo Amplifier with AM Avoidance

TPA3131D2
TPA3132D2
www.ti.com
SLOS841 – JULY 2013
PRINTED-CIRCUIT BOARD (PCB LAYOUT)
The TPA3131/32D2 can be used with a small, inexpensive ferrite bead output filter for most applications.
However, since the class-D switching edges are fast, it is necessary to take care when planning the layout of the
printed circuit board. The following suggestions will help to meet EMC requirements.
• Decoupling capacitors — The high-frequency decoupling capacitors should be placed as close to the PVCC
and AVCC terminals as possible. Large (100 μF or greater) bulk power supply decoupling capacitors should
be placed near the TPA3131/32D2 on the PVCC supplies. Local, high-frequency bypass capacitors should be
placed as close to the PVCC pins as possible. These caps can be connected to the IC GND pad directly for
an excellent ground connection. Consider adding a small, good quality low ESR ceramic capacitor between
220 pF and 1 nF and a larger mid-frequency cap of value between 100 nF and 1 µF also of good quality to
the PVCC connections at each end of the chip.
• Keep the current loop from each of the outputs through the ferrite bead and the small filter cap and back to
GND as small and tight as possible. The size of this current loop determines its effectiveness as an antenna.
• Grounding — The PVCC decoupling capacitors should connect to GND. All ground should be connected at
the IC GND, which should be used as a central ground connection or star ground for the TPA3131/32D2.
• Output filter — The ferrite EMI filter (see Figure 30) should be placed as close to the output terminals as
possible for the best EMI performance. The LC filter should be placed close to the outputs. The capacitors
used in both the ferrite and LC filters should be grounded.
For an example layout, see the TPA3131/32D2 Evaluation Module (TPA3131/32D2EVM) User Manual. Both the
EVM user manual and the thermal pad application report are available on the TI Web site at http://www.ti.com.
Copyright © 2013, Texas Instruments Incorporated
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