OUTP

OUTN

OUTP

-OUTN

Speaker

Current

OUTP

OUTN

OUTP-OUTN

Speaker

Current

OUTP

OUTN

OUTP

-OUTN

Speaker

Current

0 V

0 V

PVCC

No Output

Positive Output

Negative Output

0 A

0 A

0 V

- PVCC

16

TPA3136D2, TPA3136AD2

SLOS938F – MAY 2016 – REVISED JANUARY 2020

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9.4 Device Functional Modes

The TPA3136D2, TPA3136AD2 device is running in BD-modulation.

This is a modulation scheme that allows operation without the classic LC reconstruction filter when the amp is

driving an inductive load with short speaker wires. Each output is switching from 0 volts to the supply voltage.

The OUTPx and OUTNx are in phase with each other with no input so that there is little or no current in the

speaker. The duty cycle of OUTPx is greater than 50% and OUTNx is less than 50% for positive output voltages.

The duty cycle of OUTPx is less than 50% and OUTNx is greater than 50% for negative output voltages. The

voltage across the load sits at 0 V throughout most of the switching period, reducing the switching current, which

reduces any I2R losses in the load.

Figure 17. BD Mode Modulation