Datasheet

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C
O
C
O
V
OUT
V
OUT
GND
GND
V
DD
V
DD
V /2
DD
V
BIAS
Conventional
Capless
GND
V
DD
V
SS
V
BIAS
DirectPath
TM
Input-Blocking Capacitors
TPA6130A2
SLOS488B – NOVEMBER 2006 – REVISED FEBRUARY 2008
connected to the headphone jack shield pin. This is the voltage on which the audio output signals are centered.
This voltage reference is half of the amplifier power supply to allow symmetrical swing of the output voltages. Do
not connect the shield to any GND reference or large currents will result. The scenario can happen if, for
example, an accessory other than a floating GND headphone is plugged into the headphone connector. See the
second block diagram and waveform in Figure 36 .
Figure 36. Amplifier Applications
The DirectPath™ amplifier architecture operates from a single supply but makes use of an internal charge pump
to provide a negative voltage rail. Combining the user provided positive rail and the negative rail generated by
the IC, the device operates in what is effectively a split supply mode. The output voltages are now centered at
zero volts with the capability to swing to the positive rail or negative rail. The DirectPath™ amplifier requires no
output dc blocking capacitors, and does not place any voltage on the sleeve. The bottom block diagram and
waveform of Figure 36 illustrate the ground-referenced headphone architecture. This is the architecture of the
TPA6130A2.
DC input-blocking capacitors block the dc portion of the audio source, and allow the inputs to properly bias.
Maximum performance is achieved when the inputs of the TPA6130A2 are properly biased. Performance issues
such as pop are optimized with proper input capacitors.
The dc input-blocking capacitors may be removed provided the inputs are connected differentially and within the
input common mode range of the amplifier, the audio signal does not exceed ± 3 V, and pop performance is
sufficient.
Copyright © 2006 – 2008, Texas Instruments Incorporated 13
Product Folder Link(s): TPA6130A2