Texas Instruments TPA3200D1 - 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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