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TPA3126D2

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SLOS942 – APRIL 2018

Product Folder Links: TPA3126D2

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Copyright © 2018, Texas Instruments Incorporated

11 Layout

11.1 Layout Guidelines

The TPA3126D2 can be used with a small, inexpensive ferrite bead output filter in most applications. However,

because the Class-D switching edges are fast, the layout of the printed circuit board must be planned carefully.

The following suggestions helps 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 TPA3126D2 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.

•

Minimize the current loop from each of the outputs through the ferrite bead filter and back to GND. 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 TPA3126D2.

•

Output filter — The ferrite EMI filter (see Figure 31) 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 TPA3126D2 Evaluation Module (TPA3126D2EVM) User Guide (SLOU506). Both

the EVM user manual and the thermal pad application reports, SLMA002 and SLMA004, are available on the TI

Web site at http://www.ti.com.