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Tpa3200d1 modulation scheme – Texas Instruments TPA3200D1 User Manual

Page 18

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TPA3200D1 Modulation Scheme

0 V

−12 V

+12 V

Current

OUTP

OUTN

Differential

Voltage

Across

Load

0 V

−12 V

+12 V

Current

OUTP

OUTN

Differential

Voltage

Across

Load

Output = 0 V

Output > 0 V

TPA3200D1

SLOS442A – MAY 2005 – REVISED JULY 2005

The TPA3200D1 uses a modulation scheme that still has each output switching from ground to V

CC

. However,

OUTP and OUTN are now in phase with each other with no input. The duty cycle of OUTP is greater than 50%
and OUTN is less than 50% for positive output voltages. The duty cycle of OUTP is less than 50% and OUTN is
greater than 50% for negative output voltages. The voltage across the load is 0 V throughout most of the
switching period, greatly reducing the switching current, which reduces any I

2

R losses in the load. (See

Figure 22

.)

Figure 22. The TPA3200D1 Output Voltage and Current Waveforms Into an Inductive Load

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