TPA6138A2_15 Datasheet, PDF (1/22 Pages) Texas Instruments – TPA6138A2 DirectPath™ Headphone Driver With Adjustable Gain

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TPA6138A2
SLOS704B – JANUARY 2011 – REVISED AUGUST 2015
TPA6138A2 DirectPath™ Headphone Driver With Adjustable Gain
1 Features
•1 Stereo DirectPath™ Headphone Amplifier
– 40 mW Into 32 Ω With 3.3-V Supply
• Low THD+N < 0.01% at 10 mW Into 32 Ω
• High SNR, >90 dB
• Differential Input and Single-Ended Output
• Adjustable Gain by External Gain-Setting
Resistors
• Configurable as a Second-Order Low-Pass Filter
– Ideal for PWM Audio Sources
• Low DC Offset, <1 mV
• Ground-Referenced Outputs Eliminate DC-
Blocking Capacitors
– Reduce Board Area
– Reduce Component Cost
– Improve THD+N Performance
– No Degradation of Low-Frequency Response
Due to Output Capacitors
• Short-Circuit Protection
• Click- and Pop-Reduction Circuitry
• External Undervoltage Mute
• Active Mute Control for Pop-Free Audio On/Off
Control
• Space-Saving TSSOP Package
2 Applications
• LCD and PDP TV
• Blu-ray Disc™, DVD Players
• Set-Top Boxes
• Mini/Micro Combo Systems
• Sound Cards
• Laptops
3 Description
The TPA6138A2 is a pop-free stereo headphone
amplifier designed to allow the removal of the output
dc-blocking capacitors for reduced component count
and cost. The device is ideal for single-supply
electronics where size and cost are critical design
parameters.
Designed using TI’s patented DirectPath™
technology, The TPA6138A2 is capable of driving 25
mW into a 32-Ω load with 3.3-V supply voltage. The
device has differential inputs and uses external gain-
setting resistors that supports a gain range of ±1 V/V
to ±10 V/V. Gain can be configured individually for
each channel. The device can also be configured as
a second-order low-pass filter and is ideal for
interfacing with PWM audio sources. Audio output
compiles with ±8-kV IEC ESD protection, requiring
just a simple resistor-capacitor ESD protection circuit.
The TPA6138A2 has built-in active-mute control for
pop-free audio on/off control. The TPA6138A2 has an
external undervoltage detector that mutes the output
when the power supply is removed, ensuring a pop-
free shutdown.
Using the TPA6138A2 in audio products can reduce
component count considerably compared to
traditional headphone amplifiers. The TPA6138A2
does not require a split-rail power supply or a dc
blocking capacitor. The TPA6138A2 integrates its
own charge pump to generate a negative supply rail
that provides a clean, pop-free ground-biased audio
signal.
The TPA6138A2 is available in a 14-pin TSSOP.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (NOM)
TPA6138A2
TSSOP (14)
5.00 mm × 4.40 mm
(1) For all available packages, see the orderable addendum at
the end of the datasheet.
Simplified Diagram
OUTR+
OUTR-
CODEC
OUTL+
OUTL-
MUTE CONTROL
VBAT
Gain-Setting
Resistor
Array
TPA6138A2
INR+
INR-
OUTR
INL+
OUTL
INL-
MUTE
VDD
GND
GND
UVP
CN
VSS
CP
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.