Datasheet

NearestCompetitor
t-Time=20 s/divm
V-Voltage=1V/div
TPA3106D1
TPA3106D1
t-Time=100 s/divm
V-Voltage=10V/div
NearestCompetitor
TPA3106D1
SLOS516C –OCTOBER 2007–REVISED AUGUST 2010 www.ti.com
Adaptive Dynamic Range Control
Figure 31. 1-kHz Sine Output at 10% THD+N Figure 32. 8-kHz Sine Output at 10% THD+N
The Texas Instruments patent-pending adaptive dynamic range control (ADRC) technology removes the notch
inherent in class-D audio power amplifiers when they come out of clipping. This effect is more severe at higher
frequencies as shown in Figure 32.
Gain Setting via GAIN0 and GAIN1 Inputs
The gain of the TPA3106D1 is set by two input terminals, GAIN0 and GAIN1.
The gains listed in Table 2 are realized by changing the taps on the input resistors and feedback resistors inside
the amplifier. This causes the input impedance (Z
I
) to be dependent on the gain setting. The actual gain settings
are controlled by ratios of resistors, so the gain variation from part-to-part is small. However, the input impedance
from part-to-part at the same gain may shift by ±20% due to shifts in the actual resistance of the input resistors.
For design purposes, the input network (discussed in the next section) should be designed assuming an input
impedance of 12.8 kΩ, which is the absolute minimum input impedance of the TPA3106D1. At the lower gain
settings, the input impedance could increase as high as 38.4 kΩ
Table 2. Gain Setting
INPUT IMPEDANCE
AMPLIFIER GAIN (dB)
(kΩ)
GAIN1 GAIN0
TYP TYP
0 0 20 32
0 1 26 16
1 0 32 16
1 1 36 16
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