OUTP

OUTN

OUTP

Speaker

Current

OUTP

OUTN

Speaker

Current

OUTP

OUTN

OUTP

Speaker

Current

0 V

0 V

PVCC

No Output

Positive Output

Negative Output

0 A

0 A

0 V

TPA3116D2-Q1, TPA3118D2-Q1

SLOS862A – JULY 2015 – REVISED AUGUST 2015

www.ti.com

Figure 16. BD Mode Modulation

7.3.12.2 MODSEL = HIGH: 1SPW Modulation

The 1SPW mode alters the normal modulation scheme in order to achieve higher efficiency with a slight penalty

in THD degradation, and more attention required in the output filter selection. In 1SPW mode, the outputs

operate at approximately 15% modulation during idle conditions. When an audio signal is applied, one output

decreases and one increases. The decreasing output signal quickly rails to GND at which point all the audio

modulation takes place through the rising output. The result is that only one output is switching during a majority

of the audio cycle. Efficiency is improved in this mode due to the reduction of switching losses. The THD penalty

in 1SPW mode is minimized by the high-performance feedback loop. The resulting audio signal at each half-

output has a discontinuity each time the output rails to GND. This can cause ringing in the audio reconstruction

filter unless care is taken in the selection of the filter components and type of filter used.

16

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