TPA6139A2 Datasheet, PDF (9/22 Pages) Texas Instruments – DirectPath™ 25-mW Headphone Amplifier With Programmable-Fixed Gain

www.ti.com
TPA6139A2
SLOS700B – JANUARY 2011 – REVISED JUNE 2012
APPLICATION INFORMATION
LINE DRIVER AMPLIFIERS
Single-supply line-driver amplifiers typically require dc-blocking capacitors. The top drawing in Figure 9 illustrates
the conventional line-driver amplifier connection to the load and output signal.
DC blocking capacitors are often large in value, and a mute circuit is needed during power up to minimize click
and pop. The output capacitor and mute circuit consume PCB area and increase cost of assembly, and can
reduce the fidelity of the audio output signal.
9-12 V
Conventional solution
+
+
Co
OPAMP
+
-
Mute Circuit
Output
GND
VDD
VDD/2
MUTE
3.3 V
-
TPA6139A2
TPA 6139 A 2 Solution
Output
DirectPath
VDD
GND
VSS
MUTE
Figure 9. Conventional and DirectPath Line Driver
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.
Combining this with the built-in click and pop reduction circuit, the DirectPath™ amplifier requires no output dc
blocking capacitors.
The bottom block diagram and waveform of Figure 9 illustrate the ground-referenced line-driver architecture. This
is the architecture of the TPA6139A2.
Copyright © 2011–2012, Texas Instruments Incorporated
Product Folder Link(s) :TPA6139A2
Submit Documentation Feedback
9