INR+

INR-

INL+

INL-

OUTR

OUTL

GND

GND

VSS

CP

CN

UVP

VDD

MUTE

Gain-Setting

Resistor

Array

OUTR+

OUTR-

OUTL+

OUTL-

CODEC

VBAT

MUTE CONTROL

TPA6138A2

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Folder

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TPA6138A2

SLOS704B – JANUARY 2011 – REVISED AUGUST 2015

TPA6138A2 DirectPath™ Headphone Driver With Adjustable Gain

1 Features

3 Description

The TPA6138A2 is a pop-free stereo headphone

1

•

Stereo DirectPath™ Headphone Amplifier

amplifier designed to allow the removal of the output

–

40 mW Into 32

Ω With 3.3-V Supply

dc-blocking capacitors for reduced component count

•

Low THD+N < 0.01% at 10 mW Into 32

Ω

and cost. The device is ideal for single-supply

electronics where size and cost are critical design

•

High SNR, >90 dB

parameters.

•

Differential Input and Single-Ended Output

Designed

using

TI’s

patented

DirectPath™

•

Adjustable Gain by External Gain-Setting

technology, The TPA6138A2 is capable of driving 25

Resistors

mW into a 32-

Ω load with 3.3-V supply voltage. The

•

Configurable as a Second-Order Low-Pass Filter

device has differential inputs and uses external gain-

–

Ideal for PWM Audio Sources

setting resistors that supports a gain range of ±1 V/V

to ±10 V/V. Gain can be configured individually for

•

Low DC Offset, <1 mV

each channel. The device can also be configured as

•

Ground-Referenced Outputs Eliminate DC-

a second-order low-pass filter and is ideal for

Blocking Capacitors

interfacing with PWM audio sources. Audio output

–

Reduce Board Area

compiles with ±8-kV IEC ESD protection, requiring

just a simple resistor-capacitor ESD protection circuit.

–

Reduce Component Cost

The TPA6138A2 has built-in active-mute control for

–

Improve THD+N Performance

pop-free audio on/off control. The TPA6138A2 has an

–

No Degradation of Low-Frequency Response

external undervoltage detector that mutes the output

Due to Output Capacitors

when the power supply is removed, ensuring a pop-

free shutdown.

•

Short-Circuit Protection

•

Click- and Pop-Reduction Circuitry

Using the TPA6138A2 in audio products can reduce

component

count

considerably

compared

to

•

External Undervoltage Mute

traditional headphone amplifiers. The TPA6138A2

•

Active Mute Control for Pop-Free Audio On/Off

does not require a split-rail power supply or a dc

Control

blocking capacitor. The TPA6138A2 integrates its

•

Space-Saving TSSOP Package

own charge pump to generate a negative supply rail

that provides a clean, pop-free ground-biased audio

signal.

2 Applications

The TPA6138A2 is available in a 14-pin TSSOP.

•

LCD and PDP TV

•

Blu-ray Disc™, DVD Players

Device Information(1)

•

Set-Top Boxes

PART NUMBER

PACKAGE

BODY SIZE (NOM)

•

Mini/Micro Combo Systems

TPA6138A2

TSSOP (14)

5.00 mm × 4.40 mm

•

Sound Cards

(1) For all available packages, see the orderable addendum at

•

Laptops

the end of the datasheet.

Simplified Diagram

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.