TPA3120D2_07 Datasheet, PDF (21/27 Pages) Texas Instruments – 25-W STEREO CLASS-D AUDIO POWER AMPLIFIER

TPA3120D2
www.ti.com
SLOS507C – MARCH 2007 – REVISED MAY 2007
SE Input and SE Output (TPA312002 Stereo Configuration)
The SE input and output configuration is used with class-AB amplifiers. A block diagram of a fully SE
measurement circuit is shown in Figure 30. SE inputs normally have one input pin per channel. In some cases,
two pins are present; one is the signal and the other is ground. SE outputs have one pin driving a load through
an output ac coupling capacitor and the other end of the load is tied to ground. SE inputs and outputs are
considered to be unbalanced, meaning one end is tied to ground and the other to an amplifier input/output.
The generator should have unbalanced outputs, and the signal should be referenced to the generator ground for
best results. Unbalanced or balanced outputs can be used when floating, but they may create a ground loop that
will effect the measurement accuracy. The analyzer should have balanced inputs to cancel out any
common-mode noise in the measurement.
Generator
V_GEN
R_GEN
Evaluation Module
Audio Power
Amplifier
C_IN
R_IN
L_filt
C_filt
C_L
R_L
Analyzer
R_ANA
R_ANA
C_ANA
C_ANA
Twisted-Pair Wire
Twisted-Pair Wire
Figure 30. SE Input—SE Output Measurement Circuit
The following general rules should be followed when connecting to APAs with SE inputs and outputs:
• Use an unbalanced source to supply the input signal.
• Use an analyzer with balanced inputs.
• Use twisted pair wire for all connections.
• Use shielding when the system environment is noisy.
• Ensure the cables from the power supply to the APA, and from the APA to the load, can handle the large
currents (see Table 4)
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