Texas Instruments TPA3130D2 Evaluation Module TPA3130D2EVM TPA3130D2EVM Datenbogen
Produktcode
TPA3130D2EVM
OUTP
OUTN
10 µH
L1
10 µH
L2
C2
C3
0.68 µF
0.68 µF
OUTP
OUTN
Ferrite
Chip Bead
1 nF
1 nF
Ferrite
Chip Bead
4
- 8
W
W
4
- 8
W
W
SLOS708C – APRIL 2012 – REVISED NOVEMBER 2013
Figure 34.
AM AVOIDANCE EMI REDUCTION
To reduce interference in the AM radio band, the TPA3116D2 has the ability to change the switching frequency
via AM<2:0> pins. The recommended frequencies are listed in
via AM<2:0> pins. The recommended frequencies are listed in
. The fundamental frequency and its
second harmonic straddle the AM radio band listed. This eliminates the tones that can be present due to the
switching frequency being demodulated by the AM radio.
switching frequency being demodulated by the AM radio.
Table 6. AM Frequencies
US
EUROPEAN
AM FREQUENCY (kHz)
AM FREQUENCY (kHz)
SWITCHING FREQUENCY (kHz)
AM2
AM1
AM0
522-540
540-917
540-914
500
0
0
1
0
1
0
917-1125
914-1122
600 (or 400)
0
0
0
1125-1375
1122-1373
500
0
0
1
0
1
0
1375-1547
1373-1548
600 (or 400)
0
0
0
0
1
0
1547-1700
1548-1701
600 (or 500)
0
0
1
PRINTED-CIRCUIT BOARD (PCB LAYOUT)
The TPA3116D2 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.
•
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
and AVCC terminals as possible. Large (100
μF or greater) bulk power supply decoupling capacitors should
be placed near the TPA3116D2 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.
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.
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 TPA3116D2.
the IC GND, which should be used as a central ground connection or star ground for the TPA3116D2.
24
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